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2012 ENGINE

DESCRIPTION

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

3.6L - Service Information - Wrangler

Fig. 1: 3.6L (219.7 CID) Flexible Fuel V-6 Engine Courtesy of CHRYSLER GROUP, LLC

NOTE: WK engine shown in illustration, JK engine similar.

The 3.6 liter (219.7 CID) flexible fuel V-6 engine features Variable Valve Timing (VVT), Dual Overhead Camshafts (DOHC) and a high-pressure die-cast aluminum cylinder block with steel liners in a 60° configuration. The 3.6 liter engine has a chain driven variable discharge oil pump with a two-stage pressure regulator for improved fuel economy. The exhaust manifolds are integrated into the cylinder heads for reduced weight. The cylinders are numbered from front to rear. The right bank is numbered 1, 3, 5 and the left bank is numbered 2, 4, 6. The firing order is 1-2-3-4-5-6. The engine serial number is located on the left side of the cylinder block at the transmission flange.

DIAGNOSIS AND TESTING

ENGINE DIAGNOSIS - INTRODUCTION

viernes, 1 de octubre de 2021 06:58:22 p. m. Page 1 © 2011 Mitchell Repair Information Company, LLC. viernes, 1 de octubre de 2021 06:58:37 p. m. Page 1 © 2011 Mitchell Repair Information Company, LLC.

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Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

maintenance.

These malfunctions may be classified as either performance (e.g., engine idles rough and stalls) or mechanical (e.g., a strange noise).

Refer to ENGINE MECHANICAL DIAGNOSTIC TABLE and ENGINE PERFORMANCE DIAGNOSTIC TABLE for possible causes and corrections of malfunctions.

Refer to FUEL SYSTEM article, for the fuel system diagnosis.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that can not be isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the following diagnosis:

 Cylinder Compression Pressure Test. Refer to CYLINDER COMPRESSION PRESSURE

LEAKAGE.

 Cylinder Combustion Pressure Leakage Test. Refer to CYLINDER COMBUSTION PRESSURE

LEAKAGE.

 Engine Cylinder Head Gasket Failure Diagnosis. Refer to CYLINDER HEAD, DIAGNOSIS AND

TESTING.

 Intake Manifold Leakage Diagnosis. Refer to MANIFOLD, INTAKE, DIAGNOSIS AND TESTING.

ENGINE PERFORMANCE DIAGNOSTIC TABLE

CONDITION POSSIBLE CAUSE CORRECTION

ENGINE WILL NOT START

1. Weak battery 1. Charge or replace as necessary. Refer to BATTERY, DIAGNOSIS AND TESTING .

2. Corroded or loose

battery connections.

3. Faulty engine starting

system.

4. Faulty coil or control

unit.

5. Incorrect spark plug

2. Clean and tighten battery connections. Refer to CLEANING .

3. Diagnose engine starting system. Refer to DIAGNOSIS AND TESTING .

4. Replace ignition coil. Refer to COIL, IGNITION, 3.6L, REMOVAL .

5. Correct as necessary.

gap.

6. Incorrect cam timing. 6. Verify cam timing. Refer to Engine/Valve Timing - Standard Procedure.

7. Dirt or water in fuel

7. Clean fuel system.

system.

8. Faulty fuel pump or

8. Repair or replace as necessary.

wiring.

9. Faulty Camshaft

Position (CMP) sensor.

9. Replace sensor. Refer to SENSOR, CAMSHAFT POSITION, 3.6L, REMOVAL .

10. Faulty Crankshaft 10. Replace sensor. Refer to SENSOR,

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ENGINE STALLS OR ROUGH IDLE

ENGINE LOSS OF POWER

ENGINE MISSES ON ACCELERATION

ENGINE MISSES AT HIGH SPEED

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Position (CKP) sensor. CRANKSHAFT POSITION, REMOVAL .

1. Vacuum leak. 1. Inspect intake manifold and vacuum hoses, repair or replace as necessary.

2. Faulty Crankshaft

Position (CKP) sensor.

2. Replace sensor. Refer to SENSOR, CRANKSHAFT POSITION, REMOVAL .

3. Faulty ignition coil. 3. Replace ignition coil. Refer to COIL, IGNITION, 3.6L, REMOVAL .

4. Incorrect cam timing. 4. Verify cam timing. Refer to Engine/Valve Timing - Standard Procedure.

1. Dirty or incorrectly

gapped spark plugs.

2. Dirt or water in fuel

1. Correct as necessary. Refer to SPARK PLUG, REMOVAL .

2. Clean fuel system.

system.

3. Faulty fuel pump. 3. Replace fuel pump. Refer to MODULE, FUEL PUMP, REMOVAL .

4. Leaking cylinder

head gasket.

4. Replace cylinder head gasket. Refer to CYLINDER HEAD, REMOVAL.

5. Low compression. 5. Determine the cause and repair as necessary. Refer to CYLINDER COMBUSTION PRESSURE LEAKAGE.

6. Burned, warped or

pitted valves.

7. Plugged or restricted

6. Replace as necessary. Refer to VALVES, INTAKE AND EXHAUST, REMOVAL.

7. Inspect and replace as necessary.

exhaust system.

8. Faulty ignition coil. 8. Replace ignition coil. Refer to COIL, IGNITION, 3.6L, REMOVAL .

9. Incorrect cam timing. 9. Verify cam timing. Refer to Engine/Valve Timing - Standard Procedure.

1. Dirty or incorrectly

gapped spark plugs.

1. Correct as necessary. Refer to SPARK PLUG, REMOVAL .

2. Dirt in fuel system. 2. Clean fuel system.

3. Burned, warped or

pitted valves.

3. Replace as necessary. Refer to VALVES, INTAKE AND EXHAUST, REMOVAL.

4. Faulty ignition coil. 4. Replace ignition coil. Refer to COIL, IGNITION, 3.6L, REMOVAL .

1. Dirty or incorrectly

gapped spark plugs.

1. Correct as necessary. Refer to SPARK PLUG, REMOVAL .

4. Faulty ignition coil. 2. Replace ignition coil. Refer to COIL, IGNITION, 3.6L, REMOVAL .

3. Dirt or water in fuel

3. Clean fuel system.

system.

ENGINE MECHANICAL DIAGNOSTIC TABLE

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

CONDITION POSSIBLE CAUSES CORRECTIONS

NOISY VALVES 1. High or low oil level in

crankcase.

1. Refer to Engine/Lubrication/OIL - Standard Procedure.

2. Thin or diluted oil. 2. Change oil and filter.

3. Low oil pressure. 3. Check oil pump, if Ok, check rod and main bearings for excessive wear.

4. Dirt in lash adjusters. 4. Replace as necessary.

5. Worn rocker arms. 5. Replace as necessary.

6. Worn lash adjusters 6. Replace as necessary.

7. Worn valve guides. 7. Inspect the valve guides for wear, cracks or looseness. If either condition exists, replace the cylinder head. Refer to CYLINDER HEAD, REMOVAL.

8. Excessive runout of valve

seats on valve faces.

8. Refer to VALVES, INTAKE AND

EXHAUST, STANDARD PROCEDURE.

CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Refer to Engine/Lubrication/OIL -

Standard Procedure.

2. Low oil pressure. 2. Check oil pump, if OK, check rod and main bearings for excessive wear.

3. Thin or diluted oil. 3. Change oil and filter.

4. Excessive bearing clearance. 4. Replace as necessary.

5. Connecting rod journal out-

5. Service or replace crankshaft.

of-round.

6. Misaligned connecting rods. 6. Replace bent connecting rods.

MAIN BEARING NOISE 1. Insufficient oil supply. 1. Refer to Engine/Lubrication/OIL -

Standard Procedure.

2. Low oil pressure. 2. Check oil pump, if OK, check rod and main bearings for excessive wear.

3. Thin or diluted oil. 3. Change oil and filter.

4. Excessive bearing clearance. 4. Replace as necessary.

5. Excessive end play. 5. Check thrust washers for wear.

6. Crankshaft journal out-of

6. Service or replace crankshaft.

round.

7. Loose flywheel or torque

7. Tighten to correct torque

converter.

CYLINDER COMPRESSION PRESSURE LEAKAGE

NOTE: The results of a cylinder compression pressure test can be utilized to diagnose

several engine malfunctions.

NOTE: Ensure the battery is completely charged and the engine starter motor is in

good operating condition. Otherwise the indicated compression pressures may

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Calibrate the tester according to the manufacturer's instructions. The shop air source for testing should

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

not be valid for diagnosis purposes.

1. Clean the spark plug recesses with compressed air.

2. Remove the spark plugs and record the cylinder number of each spark plug for future reference.

3. Inspect the spark plug electrodes for abnormal firing indicators such as fouled, hot, oily, etc.

4. Disable the fuel system and perform the fuel system pressure release procedure. Refer to FUEL SYSTEM PRESSURE RELEASE .

5. Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.

6. Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders.

NOTE: The recommended compression pressures are to be used only as a guide

to diagnosing engine problems. An engine should not be disassembled to determine the cause of low compression unless some malfunction is present.

7. Compression should not be less than 689 kPa (100 psi) and not vary more than 25 percent from cylinder to cylinder.

8. If one or more cylinders have abnormally low compression pressures, repeat the compression test.

NOTE: If the same cylinder or cylinders repeat an abnormally low reading on the

second compression test, it could indicate the existence of a problem in the cylinder in question.

9. If one or more cylinders continue to have abnormally low compression pressures, perform the cylinder combustion pressure leakage test. Refer to CYLINDER COMBUSTION PRESSURE LEAKAGE.

CYLINDER COMBUSTION PRESSURE LEAKAGE

The combustion pressure leakage test provides an accurate means for determining engine condition.

Combustion pressure leakage testing will detect:

 Exhaust and intake valve leaks (improper seating).

 Leaks between adjacent cylinders or into water jacket.

 Any causes for combustion/compression pressure loss.

1. Check the coolant level and fill as required. DO NOT install the radiator cap.

2. Start and operate the engine until it attains normal operating temperature, then turn the engine OFF.

3. Remove the spark plugs.

4. Remove the oil filler cap.

5. Remove the air cleaner hose.

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maintain 483 kPa (70 psi) minimum, 1, 379 kPa (200 psi) maximum and 552 kPa (80 psi) recommended.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

7. Perform the test procedures on each cylinder according to the tester manufacturer's instructions. Set piston of cylinder to be tested at TDC compression. While testing, listen for pressurized air escaping through the throttle body, tailpipe and oil filler cap opening. Check for bubbles in the radiator coolant.

All gauge pressure indications should be equal, with no more than 25% leakage.

FOR EXAMPLE: At 552 kPa (80 psi) input pressure, a minimum of 414 kPa (60 psi) should be maintained in the cylinder.

Refer to CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART.

CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART

CONDITION POSSIBLE CAUSE CORRECTION

AIR ESCAPES THROUGH THROTTLE BODY

Intake valve bent, burnt, or not seated properly

Inspect valve and valve seat. Reface or replace, as necessary. Inspect valve springs. Replace as necessary.

AIR ESCAPES THROUGH TAILPIPE

Exhaust valve bent, burnt, or not seated properly

Inspect valve and valve seat. Reface or replace, as necessary. Inspect valve springs. Replace as necessary.

AIR ESCAPES THROUGH RADIATOR

MORE THAN 50% LEAKAGE FROM ADJACENT CYLINDERS

MORE THAN 25% LEAKAGE AND AIR ESCAPES THROUGH OIL FILLER CAP OPENING ONLY

Head gasket leaking or cracked cylinder head or block

Head gasket leaking or crack in cylinder head or block between adjacent cylinders

Stuck or broken piston rings; cracked piston; worn rings and/or cylinder wall

Remove cylinder head and inspect. Replace defective part

Remove cylinder head and inspect. Replace gasket, head, or block as necessary

Inspect for broken rings or piston. Measure ring gap and cylinder diameter, taper and out-of-round. Replace defective part as necessary

OIL CONSUMPTION TEST AND DIAGNOSIS

DIAGNOSTIC PROCEDURES

The following diagnostic procedures are used to determine the source of excessive internal oil Consumption, these procedures and tests apply to vehicles with 50, 000 miles or less.

NOTE: Engine oil consumption may be greater than normal during engine break-in.

Repairs should be delayed until vehicle has been driven at least 7, 500 miles.

Severe service (high ambient temperature, short trips, heavy loading, trailer towing, taxi, off-road, or law enforcement use) may result in greater oil consumption than normal.

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Sustained high speed driving and high engine RPM operation may result in increased oil consumption.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Failure to comply with the recommended oil type and viscosity rating, as outlined in the owner's manual, may impact oil economy as well as fuel economy.

Oil consumption may increase with vehicle age and mileage due to normal engine wear.

NOTE: Because a few drops of external oil leakage per mile can quickly account for the

loss of one quart of oil in a few hundred miles, ensure no external engine oil leaks are present.

 Oil leakage is not the same as oil consumption and all external leakage must be eliminated before

any action can be taken to verify and/or correct oil consumption complaints.

 Verify that the engine has the correct oil level dipstick and dipstick tube installed.

 Verify that the engine is not being run in an overfilled condition. Check the oil level 15 minutes

after a hot shutdown with the vehicle parked on a level surface. In no case should the level be above MAX or the FULL mark on the dipstick.

OIL CONSUMPTION TEST

1. Check the oil level at least 15 minutes after a hot shutdown.

2. If the oil level is low, top off with the proper viscosity and API service level engine oil. Add one bottle of MOPAR® 4-In-1 Leak Detection Dye into the engine oil.

3. Tamper proof the oil pan drain plug, oil filter, dipstick and oil fill cap.

4. Record the vehicle mileage.

5. Instruct the customer to drive the vehicle as usual.

6. Ask the customer to return to the servicing dealer after accumulating 500 miles, Check the oil level at least 15 minutes after a hot shutdown. If the oil level is half way between the "FULL" and "ADD" mark continue with the next step.

7. Using a black light, re-check for any external engine oil leaks, repair as necessary, if no external engine oil leaks are present, continue with oil consumption diagnosis.

OIL CONSUMPTION DIAGNOSIS

1. Check the positive crankcase ventilation (PCV) system. Make sure the system is not restricted and the PCV valve has the correct part number and correct vacuum source (18-20 in. Hg at idle below 3000 ft. above sea level is considered normal).

2. Perform a CYLINDER COMPRESSION PRESSURE LEAKAGE test and CYLINDER-TO- CYLINDER LEAKAGE TEST using the standard leak down gauge following manufacturers suggested best practices.

NOTE: Verify the spark plugs are not oil saturated. If the spark plugs are oil

saturated and compression is good it can be assumed the valve seals or valve guides are at fault.

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

3. If one or more cylinders have more than 15% leak down further engine tear down and inspection will be required.

TOP 19 REASONS THAT MAY LEAD TO ENGINE OIL CONSUMPTION

1. Tapered and Out-of-Round Cylinders

The increased piston clearances permit the pistons to rock in the worn cylinders. While tilted momentarily, an abnormally large volume of oil is permitted to enter on one side of the piston. The rings, also tilted in the cylinder, permit oil to enter on one side. Upon reversal of the piston on each stroke, some of this oil is passed into the combustion chamber.

2. Distorted Cylinders

This may be caused by unequal heat distribution or unequal tightening of cylinder head bolts. This condition presents a surface which the rings may not be able to follow completely. In this case, there may be areas where the rings will not remove all of the excess oil. When combustion takes place, this oil will be burned and cause high oil consumption.

3. Improper operation of "PCV "system

The main purpose of the Positive Crankcase Ventilation (PCV) valve is to recirculate blow-by gases back from the crankcase area through the engine to consume unburned hydrocarbons. The PCV system usually has a one way check valve and a make up air source. The system uses rubber hoses that route crankcase blow by gases to the intake manifold. Vacuum within the engine intake manifold pulls the blow by gases out of the crankcase into the combustion chamber along with the regular intake air and fuel mixture.

The PCV system can become clogged with sludge and varnish deposits and trap blow by gases in the crankcase. This degrades the oil, promoting additional formation of deposit material. If left uncorrected, the result is plugged oil rings, oil consumption, rapid ring wear due to sludge buildup, ruptured gaskets and seals due to crankcase pressurization.

4. Worn Piston Ring Grooves

For piston rings to form a good seal, the sides of the ring grooves must be true and flat - not flared or shouldered. Piston rings in tapered or irregular grooves will not seal properly and, consequently, oil will pass around behind the rings into the combustion chamber.

5. Worn, Broken or Stuck Piston Rings

When piston rings are broken, worn or stuck to such an extent that the correct tension and clearances are not maintained, this will allow oil to be drawn into the combustion chamber on the intake stroke and hot gases of combustion to be blown down the cylinder past the piston on the power stroke. All of these conditions will result in burning and carbon build up of the oil on the cylinders, pistons and rings.

Cracked or Broken Ring Lands

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Cracked or broken ring lands prevent the rings from seating completely on their sides and cause oil

increase oil consumption; dirty oil by nature is also consumed at a higher rate than clean oil.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

pumping. This condition will lead to serious damage to the cylinders as well as complete destruction of the pistons and rings. Cracked or broken ring lands cannot be corrected by any means other than piston replacement.

7. Worn Valve Stems and Guides

When wear has taken place on valve stems and valve guides, the vacuum in the intake manifold will draw oil and oil vapor between the intake valve stems and guides into the intake manifold and then into the cylinder where it will be burned.

8. Bent or Misaligned Connecting Rods

Bent or misaligned connecting rods will not allow the pistons to ride straight in the cylinders. This will prevent the pistons and rings from forming a proper seal with the cylinder walls and promote oil consumption. In addition, it is possible that a bearing in a bent connect rod will not have uniform clearance on the connecting rod wrist pin. Under these conditions, the bearing will wear rapidly and throw off an excessive amount of oil into the cylinder.

9. Fuel Dilution

If raw fuel is allowed to enter the lubrication system, the oil will become thinner and more volatile and will result in higher oil consumption. The following conditions will lead to higher oil consumption;

 Excess fuel can enter and mix with the oil via a leaking fuel injector

 Gasoline contaminated with diesel fuel

 Restricted air intake

 Excessive idling

10. Contaminated Cooling Systems

Corrosion, rust, scale, sediment or other formations in the water jacket and radiator will prevent a cooling system from extracting heat efficiently. This is likely to cause cylinder distortion thus leading to higher oil consumption.

11. Oil Viscosity

The use of oil with a viscosity that is too light may result in high oil consumption. Refer to the vehicle owner's manual for the proper oil viscosity to be used under specific driving conditions and/or ambient temperatures.

12. Dirty Engine Oil

Failure to change the oil and filter at proper intervals may cause the oil to be so dirty that it will promote accumulation of sludge and varnish and restrict oil passages in the piston rings and pistons. This will

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Increasing performance through the use of performance/power enhancement products to a stock or factory

surface.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

13. Crankcase Overfull

Due to an error in inserting the oil dip stick so that it does not come to a seat on its shoulder, a low reading may be obtained. Additional oil may be added to make the reading appear normal with the stick in this incorrect position which will actually make the oil level too high. If the oil level is so high that the lower ends of the connecting rods touch the oil in the oil pan excessive quantities of oil will be thrown on the cylinder walls and some of it will work its way up into the combustion chamber.

14. Excessively High Oil Pressure

A faulty oil pressure relief valve may cause the oil pressure to be too high. The result will be that the engine will be flooded with an abnormally large amount of oil in a manner similar to that which occurs with worn bearings. This condition may also cause the oil filter to burst.

15. Aftermarket Performance Chips and Modification

engine will increase the chance of excessive oil consumption.

16. Lugging Engine

Lugging is running the engine at a lower RPM in a condition where a higher RPM (more power/torque) should be implemented. Especially susceptible on vehicles equipped with a manual transmission. This driving habit causes more stress loading on the piston and can lead to increases in engine oil consumption.

17. Turbocharged Engines

There is a possibility for PCV "push-over" due to higher crankcase pressure (as compared to naturally aspirated engines) which is normal for turbocharged engines. This condition causes varying amounts of engine oil to enter the intake manifold, charge air cooler and associated plumbing to and from the charge air cooler, also a leaking turbocharger seal will draw oil into the combustion chamber where it will burn (blue smoke from tail pipe may be present) and form carbon deposits which contribute to further oil consumption as they interfere with proper engine function.

18. Restricted Air Intake

Excessive restriction in the air intake system will increase engine vacuum and can increase oil consumption, an extremely dirty air filter would be one example of this situation.

19. Intake Manifold port seals

Engines that have a "V" configuration and a "wet valley" (3.3/3.8L) could draw oil into the intake ports due to improper sealing between the intake manifold ports and cylinder head. Causes may include improper torque of intake manifold bolts, corrosion (aluminum intake manifold) and or warped sealing

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ENGINE LUBRICATION DIAGNOSTIC TABLE

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

CONDITION POSSIBLE CAUSES CORRECTION

OIL LEAKS 1. Gaskets and O-rings.

1. Replace as necessary.

Misaligned or damaged. (a) Loose fasteners, broken or

porous metal parts.

(a) Tighten fasteners, Repair or replace metal parts.

2. Crankshaft rear oil seal. 2. Replace rear crankshaft oil seal. Refer to SEAL, CRANKSHAFT OIL, REAR, REMOVAL.

3. Crankshaft seal flange.

3. Polish or replace crankshaft.

Scratched, nicked or grooved.

4. Oil pan flange cracked. 4. Replace oil pan. Refer to PAN, OIL, REMOVAL.

5. Engine timing cover seal,

damaged or misaligned.

5. Replace seal. Refer to SEAL,

CRANKSHAFT OIL, FRONT, REMOVAL.

6. Scratched or damaged

6. Polish or replace damper.

vibration damper hub.

OIL PRESSURE DROP 1. Low oil level. 1. Check and correct oil level.

2. Faulty oil pressure sensor. 2. Replace sensor. Refer to SENSOR, OIL PRESSURE, REMOVAL.

3. Low oil pressure. 3. Check main bearing clearance. Refer to BEARING(S), CRANKSHAFT, MAIN, STANDARD PROCEDURE.

3. Check rod bearing clearance. Refer to

BEARING(S), CONNECTING ROD, STANDARD PROCEDURE.

4. Clogged oil filter. 4. Replace oil filter. Refer to FILTER, ENGINE OIL, REMOVAL.

5. Worn oil pump. 5. Replace oil pump. Refer to PUMP, ENGINE OIL, REMOVAL.

6. Thin or diluted oil. 6. Change oil and filter. Refer to

Engine/Lubrication/OIL - Standard Procedure.

7. Excessive bearing clearance. 7. Replace crankshaft bearings. Refer to

BEARING(S), CRANKSHAFT, MAIN, STANDARD PROCEDURE.

7. Replace rod bearings. Refer to

BEARING(S), CONNECTING ROD, STANDARD PROCEDURE.

8. Oil pump relief valve stuck. 8. Replace oil pump. Refer to PUMP, ENGINE OIL, REMOVAL.

9. Oil pump pick-up tube loose,

damaged or clogged.

9. Replace oil pump pick-up. Refer to PICK-UP, OIL PUMP, REMOVAL.

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created.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

OIL PUMPING AT RINGS;

1. Worn or damaged rings. 1. Hone cylinder bores and replace

SPARK PLUGS FOULING

2. Carbon in oil ring slots. 2. Replace rings. Refer to ROD,

3. Worn valve guides. 3. Replace cylinder heads. Refer to

4. Leaking valve guide seals. 4. Replace valve guide seals. Refer to

STANDARD PROCEDURE

DUST COVERS AND CAPS

rings. Refer to RING(S), PISTON, STANDARD PROCEDURE.

PISTON AND CONNECTING, REMOVAL.

CYLINDER HEAD, REMOVAL.

SEAL(S), VALVE GUIDE, REMOVAL.

Fig. 2: Covers/Caps Courtesy of CHRYSLER GROUP, LLC

Due to the high amounts of failures cased by dust, dirt, moisture and other foreign debris being introduced to the engine during service. Covers or caps are needed to reduce the possible damage that can be caused or

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in-place gaskets and sealers

must

free of grease or oil. Surfaces should be cleaned with Mopar

brake parts

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 3: Opening Cover Courtesy of CHRYSLER GROUP, LLC

Covers over openings will reduce any possibilities for foreign materials to enter the engine systems. Using miller tool (special tool #10368, Set, Universal Protective Cap), Select the appropriated cover needed to the procedure.

REPAIR DAMAGED OR WORN THREADS

CAUTION: Be sure that the tapped holes maintain the original center line.

Damaged or worn threads can be repaired. Essentially, this repair consists of:

 Drilling out worn or damaged threads.

 Tapping the hole with a special Heli-Coil Tap, or equivalent.

 Installing an insert into the tapped hole to bring the hole back to its original thread size.

FORM-IN-PLACE GASKETS AND SEALERS

NOTE: All of the sealants mentioned below are not used on every engine, they are

listed as a general reference guide. See appropriate service information for specific sealer usage.

There are numerous places where form-in-place gaskets are used on the engine. Care must be taken when applying form-in-place gaskets to assure obtaining the desired results.Do not use form-in-place gasket material unless specified. Bead size, continuity, and location are of great importance. Too thin a bead can result in leakage while too much can result in spill-over which can break off and obstruct fluid feed lines. A continuous bead of the proper width is essential to obtain a leak-free gasket. All sealing surfaces that use form-

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cleaner prior to sealer application. After the sealer is applied, the parts should be assembled in no more than 10

joint locations, a 3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the center of the gasket contact area.

6.35 mm (1/8 or 1/4 in.) drop is placed in the center of the gasket contact area. Uncured sealant may be removed

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

minutes.

There are numerous types of form-in-place gasket materials that are used in the engine area. Mopar® Engine RTV GEN II, Mopar® ATF-RTV, and Mopar® Gasket Maker gasket materials, each have different properties and can not be used in place of the other.

MOPAR® ENGINE RTV GEN II is used to seal components exposed to engine oil. This material is a specially designed black silicone rubber RTV that retains adhesion and sealing properties when exposed to engine oil. Moisture in the air causes the material to cure. This material is available in three ounce tubes and has a shelf life of one year. After one year this material will not properly cure. Always inspect the package for the expiration date before use.

MOPAR® ATF RTV is a specifically designed black silicone rubber RTV that retains adhesion and sealing properties to seal components exposed to automatic transmission fluid, engine coolants, and moisture. This material is available in three ounce tubes and has a shelf life of one year. After one year this material will not properly cure. Always inspect the package for the expiration date before use.

MOPAR® GASKET MAKER is an anaerobic type gasket material. The material cures in the absence of air when squeezed between two metallic surfaces. It will not cure if left in the uncovered tube. The anaerobic material is for use between two machined surfaces. Do not use on flexible metal flanges.

MOPAR® BED PLATE SEALANT is a unique (green-in-color) anaerobic type gasket material that is specially made to seal the area between the bed plate and cylinder block without disturbing the bearing clearance or alignment of these components. The material cures slowly in the absence of air when torqued between two metallic surfaces, and will rapidly cure when heat is applied.

MOPAR® THREEBOND ENGINE RTV SEALANT is a unique gasket material that is specially made to retain adhesion and sealing properties when used to seal components exposed to engine oil.

SEALER APPLICATION

Mopar® Gasket Maker material should be applied sparingly 1 mm (0.040 in.) diameter or less of sealant to one gasket surface. Be certain the material surrounds each mounting hole. Excess material can easily be wiped off. Components should be torqued in place within 15 minutes. The use of a locating dowel is recommended during assembly to prevent smearing material off the location.

Mopar® Engine RTV GEN II or ATF RTV gasket material should be applied in a continuous bead approximately 3 mm (0.120 in.) in diameter. All mounting holes must be circled. For corner sealing and "T"

Uncured sealant may be removed with a shop towel. Components should be torqued in place while the sealant is still wet to the touch (within 10 minutes). The usage of a locating dowel is recommended during assembly to prevent smearing material off the location.

Mopar® Threebond Engine RTV Sealant gasket material should be applied in a continuous bead approximately 3 mm (0.120 in.) in diameter. The gasket surfaces should be cleaned with isopropyl alcohol wipes in preparation for sealant application. All mounting holes must be circled. For corner sealing and "T" joint locations, a 3.17 or

Page 15

with a shop towel. Components should be assembled within 20 minutes and torqued in place within 45 minutes.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

The usage of a locating dowel is recommended during assembly to prevent smearing material off the location.

ENGINE GASKET SURFACE PREPARATION

Fig. 4: Proper Tool Usage For Surface Preparation Courtesy of CHRYSLER GROUP, LLC

1 - ABRASIVE PAD 2 - 3M ROLOC™ BRISTLE DISC 3 - PLASTIC/WOOD SCRAPER

To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.

Never use the following to clean gasket surfaces:

 Metal scraper.

 Abrasive pad or paper to clean cylinder block and head.

 High speed power tool with an abrasive pad or a wire brush (1).

NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.

Only use the following for cleaning gasket surfaces:

 Solvent or a commercially available gasket remover

 Plastic or wood scraper (3).

 Drill motor with 3M Roloc™ Bristle Disc (white or yellow) (2).

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

CAUTION: Excessive pressure or high RPM (beyond the recommended speed), can

damage the sealing surfaces. The mild (white, 120 grit) bristle disc is recommended. If necessary, the medium (yellow, 80 grit) bristle disc may be used on cast iron surfaces with care.

SPECIFICATIONS

GENERAL SPECIFICATIONS

DESCRIPTION SPECIFICATION

Type 60° DOHC V-6 24-Valve Compression Ratio 10.2:1 Lead Cylinder #1 Right Bank Firing Order 1-2-3-4-5-6

Metric Standard

Displacement 3.6 Liters 220 Cubic Inches Bore and Stroke 96.0 x 83.0 mm 3.779 in. x 3.268 in.

CYLINDER BLOCK

Description

Metric Standard

Specification

Cylinder Bore Diameter - Grade 1 95.995 mm ± 0.005 mm 3.7793 in. ± 0.0002 in. Cylinder Bore Diameter - Grade 2 96.005 mm ± 0.005 mm 3.7797 in. ± 0.0002 in. Cylinder Bore Out-of-Round (Max.) 0.009 mm 0.00035 in. Cylinder Bore Cylindricity 0.014 mm 0.0006 in. Crankshaft Bore Taper* (Max.) 0.006 mm 0.0002 in. *Measured over length of bulkhead

PISTONS

Description

Metric Standard

Specification

Material Cast Aluminum Alloy Piston Diameter (Metal to Metal) -

Grade 1 Piston Diameter (Metal to Metal) -

Grade 2 Piston Diameter (Metal to

Coating) - Grade 1 Piston Diameter (Metal to

Coating) - Grade 2 Clearance at Size Location (Metal

to Metal)

95.955 mm ± 0.005 mm 3.7778 in. ± 0.0002 in.

95.965 mm ± 0.005 mm 3.7781 in. ± 0.0002 in.

95.970 - 96.000 mm 3.7783 - 3.7795 in.

95.980 - 96.010 mm 3.7787 - 3.7835 in.

0.030 - 0.050 mm 0.0012 - 0.0020 in.

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Clearance at Size Location (Metal to Coating)

0.010 - 0.030 mm 0.0004 - 0.0012 in.

Piston Weight 354 - 364 grams 12.487 - 12.840 oz. Piston Pin Offset 0.8 mm 0.031 in. Piston Ring Groove Diameter -

No. 1 Piston Ring Groove Diameter -

No. 2 Piston Ring Groove Diameter -

No. 3

88.24 - 88.44 mm 3.474 - 3.482 in.

86.54 - 86.74 mm 3.407 - 3.415 in.

89.16 - 89.36 mm 3.510 - 3.518 in.

PISTON PINS

Description

Metric Standard

Specification

Type Full Floating Pin Diameter 21.9985 ± 0.0015 mm 0.86608 ± 0.00006 in. Clearance in Piston 0.002 - 0.011 mm 0.0001 - 0.0004 in. Clearance in Rod 0.011 - 0.024 mm 0.0004 - 0.0009 in.

PISTON RINGS

Description

Metric Standard

Specification

Ring Gap - Number 1 Ring (Top) 0.25 - 0.40 mm 0.010 - 0.016 in. Ring Gap - Number 2 Ring (Center) 0.30 - 0.45 mm 0.012 - 0.018 in. Ring Gap - Oil Control Ring (Steel Rails) 0.15 - 0.66 mm 0.006 - 0.026 in.

PISTON RING SIDE CLEARANCE

Description

Metric Standard

Specification

Number 1 Ring (Top) 0.025 - 0.083 mm 0.0010 - 0.0033 in. Number 2 Ring (Center) 0.030 - 0.078 mm 0.0012 - 0.0031 in. Oil Control Ring (Steel Rails) 0.007 - 0.173 mm 0.0003 - 0.0068 in.

PISTON RING WIDTH

Description

Metric Standard

Specification

Number 1 Ring (Top) 3.00 - 3.20 mm 0.118 - 0.126 in. Number 2 Ring (Center) 3.59 - 3.85 mm 0.141 - 0.152 in. Oil Control Ring (Steel Rails) 1.930 - 2.083 mm 0.076 - 0.082 in.

CONNECTING RODS

Description

Specification

Page 18

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Metric Standard

Bearing Clearance (With Crush) 0.023 - 0.064 mm 0.0009 - 0.0025 in. Side Clearance 0.070 - 0.370 mm 0.0028 - 0.0146 in. Side Clearance (Max.) 0.370 mm 0.0146 in. Piston Pin Bore Diameter 22.016 ± 0.005 mm 0.8668 ± 0.0002 in. Bearing Bore Out of Round (Max.) 0.008 mm 0.0003 in. Total Weight (Less Bearing) 546.7 ± 8 grams 19.28 ± 0.28 oz.

CRANKSHAFT MAIN BEARING JOURNALS

Description

Metric Standard

Specification

Diameter 71.996 ± 0.009 mm 2.8345 ± 0.0035 in. Bearing Clearance 0.024 - 0.050 mm 0.0009 - 0.0020 in. Bearing Clearance (Max.) 0.050 mm 0.0020 in. Out of Round (Max.) 0.005 mm 0.0002 in. Taper (Max.) 0.005 mm 0.0002 in. End Play 0.050 - 0.290 mm 0.0020 - 0.0114 in. End Play (Max.) 0.290 mm 0.0114 in.

CONNECTING ROD JOURNALS

Description

Metric Standard

Specification

Diameter 59.0 ± 0.009 mm 2.3228 ± 0.0035 in. Bearing Clearance 0.023 - 0.064 mm 0.0009 - 0.0025 in. Out of Round (Max.) 0.005 mm 0.0002 in. Taper (Max.) 0.005 mm 0.0002 in.

CAMSHAFT

Description

Metric Standard

Specification

Bore Diameter - No. 1 Cam Towers 32.020 - 32.041 mm 1.2606 - 1.2615 in. Bore Diameter - No. 2, 3, 4 Cam Towers 24.020 - 24.041 mm 0.9457 - 0.9465 in. Bearing Journal Diameter - No. 1 31.976 - 31.995 mm 1.2589 - 1.2596 in. Bearing Journal Diameter - No. 2, 3, 4 23.977 - 23.996 0.9440 - 0.9447 in. Bearing Clearance - No. 1 0.025 - 0.065 mm 0.00010 - 0.0026 in. Bearing Clearance - No. 2, 3, 4 0.024 - 0.064 mm 0.0009 - 0.0025 in. End Play 0.075 - 0.251 mm 0.003 - 0.010 in.

VALVE TIMING-INTAKE VALVES

Description Specification

Opens 2° (ATDC)

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2012 ENGINE 3.6L - Service Information - Wrangler

Closes 82° (ABDC) or 262° (ATDC) Duration 260° Centerline 128° Note: Units are in crank degrees, using 0.1524 mm (0.006 in.) valve lift as the threshold.

VALVE TIMING-EXHAUST VALVES

Description Specification

Opens 59° (BBDC) or 239° (BTDC) Closes 12° (ATDC) Duration 251° Valve Overlap 10° Note: Units are in crank degrees, using 0.1524 mm (0.006 in.) valve lift as the threshold.

CYLINDER HEAD

Description

Metric Standard

Specification

Gasket Thickness* (Compressed) 0.48 - 0.60 mm 0.019 - 0.024 in. Flatness (Head Gasket Surface) 0.09 mm 0.0035 in. Valve Seat Angle 44.75° ± 0.25° from the valve guide axis Valve Seat Runout (relative to the valve guide

axis) - Intake and Exhaust

0.050 mm 0.002 in.

Intake Valve Seat Width 1.0 - 1.2 mm 0.04 - 0.05 in. Exhaust Valve Seat Width 1.41 - 1.61 mm 0.055 - 0.063 in. Guide Bore Diameter (Std.) 6.00 - 6.02 mm 0.236 - 0.237 in. Valve Guide Height** - Intake and Exhaust 16.05 - 16.55 mm 0.632 - 0.652 in.

*Measured at the fire ring, not at the outer edge

**Measured from cylinder head valve spring seat surface to top of guide

VALVES

Description

Metric Standard

Specification

Face Angle 45.25° ± 0.25° Head Diameter - Intake 39.0 ± 0.100 mm 1.535 ± 0.004 in. Head Diameter - Exhaust 30.0 ± 0.100 mm 1.181 ± 0.004 in. Length-Intake (Overall) 116.54 ± 0.23 mm 4.588 ± 0.009 in. Length-Exhaust (Overall) 115.6 ± 0.23 mm 4.551 ± 0.009 in. Stem Diameter - Intake 5.968 ± 0.009 mm 0.2350 ± 0.0004 in. Stem Diameter - Exhaust 5.961± 0.009 mm 0.2347 ± 0.0004 in. Stem-to-Guide Clearance - Intake (New) 0.023 - 0.061 mm 0.0009 - 0.0024 in. Stem-to-Guide Clearance - Exhaust (New) 0.030 - 0.068 mm 0.0012 - 0.0027 in. Stem-to-Guide Clearance-Intake (Max.,

Rocking Method)

0.29 mm 0.011 in.

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Stem-to-Guide Clearance - Exhaust (Max., Rocking Method)

0.37 mm 0.015 in.

Valve Lift-Intake (Zero Lash) 10.3 mm 0.406 in. Valve Lift-Exhaust (Zero Lash) 10.0 mm 0.394 in. Valve Stem Tip Height* - Intake 52.4 - 53.5 mm 2.063 - 2.106 in. Valve Stem Tip Height* - Exhaust 51.8 - 52.9 mm 2.039 - 2.083 in. *Valve tip to aluminum spring seat boss

VALVE SPRING

Description

Free Length - Intake AND Exhaust (Approx.)

Spring Force - Intake AND Exhaust (Valve Closed)

Metric Standard

52.5 mm 2.067 in.

295 ± 13 N @ 40.0 mm 66 ± 3 lbs. @ 1.57 in.

Specification

Spring Force - Intake (Valve Open) 688 ± 31 N @ 10.3 mm 155 ± 7 lbs. @ 0.4055 in. Spring Force - Exhaust (Valve Open) 676 ± 30 N @ 10.0 mm 152 ± 6 lbs. @ 0.3937 in. Number of Coils - Intake AND Exhaust 9.35 Wire Diameter - Intake AND Exhaust 3.18 x 3.99 mm (ovate) 0.125 x 0.157 in. (ovate) Installed Height - Intake AND Exhaust

(Spring seat top to bottom of retainer)

40.0 mm 1.575 in.

OIL PRESSURE

Description

Metric Standard

Specification

(NOTE: At Normal Operating Temperatures) Pressure @ Curb Idle Speed* 34.7 kPa Min. 5 psi Min. Pressure @ 600 - 1200 RPM 34.7 (warm) - 958.0 (cold) kPa 5 (warm) - 139 (cold) psi Pressure @ 1201 - 3500 RPM 206.8 (warm) - 958.0 (cold) kPa 30 (warm) - 139 (cold) psi Pressure @ 3501 - 6400 RPM 427.0 (warm) - 958.0 (cold) kPa 62 (warm) - 139 (cold) psi *CAUTION: If oil pressure is zero at idle, DO NOT run engine at 3000 RPM.

TORQUE SPECIFICATIONS

DESCRIPTION N.m Ft. Lbs. In. Lbs.

Air Inlet Hose -

Band Clamps

Air Inlet Hose to

Core Support

A/C Compressor

4 - 35

12 - 106

28 21 -

to Engine - M8

Bolts

Camshaft Chain

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Tensioner

(Primary) - M6

12 - 106

T30

Camshaft Chain Guide (Primary)

12 - 106

- M6 T30

Camshaft Chain

Idler Sprocket -

25 18 -

M8 T45

Camshaft Chain

12 - 106 LH Tensioner (Secondary) -

M6 T30

Camshaft Chain

LH Guide

(Secondary) -

12 - 106

M6 T30

Camshaft Chain

RH Tensioner (Secondary) -

12 - 106

M6 T30

Camshaft Chain

RH Guide

(Secondary) -

12 - 106

M6 T30

Camshaft

Position (CMP)

Sensor to

9 - 80

Cylinder Head -

6M T30

Camshaft

9.5 - 84

Bearing Cap -

M6 T30

Connecting Rod

Cap - M9 Bolts

20 + 90° Turn 15 + 90° Turn -

Coolant Pump to

Engine Timing

Cover - M6

12 - 106

Bolts

Coolant

Crossover

Housing to

Engine Timing

12 - 106

Cover - M6

Bolts

Crankshaft 10 - 89

Page 22

Target Wheel to Counterweight -

M6 T30

Crankshaft Outer

Main Bearing

Cap and

Windage Tray -

M8 Bolts

Crankshaft Inner

Main Bearing

Cap - M11 Bolts

Crankshaft Side

Main Bearing

Cap (Tie Bolt) -

M8 Bolts

Crankshaft

Vibration

Damper - M16

Bolt

Crankshaft

Position (CKP)

Sensor to Engine

Block - M6 Bolt Crankshaft Rear

Oil Seal Retainer

- M6 T30

Cylinder Head

Oil Restrictor -

M8 Plug

Cylinder Head to

Engine Block -

M12 Bolts in

Sequence

Cylinder Head

Cover - M6

Bolts

Engine Coolant

Temperature

(ECT) Sensor

Left/Right

Engine Mount

Isolator to

Engine - Bolts

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

21 + 90° Turn 16 + 90° Turn -

20 + 90° Turn 15 + 90° Turn -

28 21 -

40 + 105° Turn 30 + 105° Turn -

12 - 106

15 - 133

See INSTALLATION Procedure.

12 - 106

11 - 97

61 45 -

Left Engine

Mount

12 - 106

Heatshield to

Page 23

Engine Mount -

M6 Bolts

Left/Right

Engine Mount

Isolator to Frame

- Bolt and Nut Flexplate to

Crankshaft -

M10 Bolts

Fuel Rail to

Lower Intake

Manifold - M6

Bolts

Heater Core

Coolant Supply

Tubes to Right

Upper Intake

Manifold

Support Bracket

- M6 Nuts Ignition

Capacitor to

Cylinder Head -

M6 Bolts

Ignition Coil to

Cylinder Head

Cover - M6

Bolts

Intake Manifold

(Upper) - M6

Bolts

Intake Manifold

(Lower) - M6

Bolts

Negative Battery

Cable to Battery

Engine Block

Oil Gallery -

M24 Plugs

Oil Control

Valve - Cam

Phaser M18

Upper Oil Pan to

Engine Block -

M8 Bolts

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

61 45 -

95 70 -

7 - 62

10 - 89

8 - 71

5 - 45

10 + 1250° Turn - 89 + 1250° Turn

150 110 -

25 18 -

Transmission to

Page 24

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Upper Oil Pan -

M10 Bolts

Torque

Converter Dust

Shield - M8 Bolt Oil Cooler to Oil

Filter Housing

Screws

Upper Oil Pan to

Rear Seal

Retainer - M6

Bolts

Oil Pan Drain -

Plug M14

Oil Pressure

Sensor to Oil

Filter Housing

Oil Temperature

Sensor to Oil

Filter Housing

Lower Oil Pan to

Upper Oil Pan -

M6 Bolts

Piston Oil

Cooler Jet to

Engine Block -

Oil Filter

Housing/Oil

Cooler to Engine

Block - M6

Bolts

Oil Filter

Housing Cap

Oil Pump to

Block - M6

Bolts

Oil Level

Indicator to

Cylinder Head -

M6 Bolt

Oil Pump

Sprocket - M8

T45

Oil Pump Pick

Up Tube Bracket

55 41 -

12 - 106

4 - 35

12 - 106

27 20 -

20 - 177

11 - 97

6 - 53

12 - 106

25 18 -

12 - 106

25 18 -

12 - 106

Page 25

to Windage Tray

- M6 Bolt

Oil Pump Pick

Up Tube to Oil

Pump - M6 Bolt

Oxygen Sensor

to Exhaust Pipe -

M18

PCV Valve - M5

T25

Power Steering

Pump Bracket to

Engine - M8

Bolts

Spark Plug to

Cylinder Head -

M12

Starter Mounting

- M10 Bolts

Throttle Body -

M6 Bolts

Engine Timing

Cover - M6

Bolts

Transmission to

Engine Block -

M10 Bolts

Transmission

Fluid Indicator

to Transmission

- M6 Bolt Torque

Converter - M8

Bolts

Left Rear Upper Intake Manifold Support Bracket

to Upper Intake

Manifold - M6

Nuts

Left Rear Upper Intake Manifold Support Bracket

to Cylinder Head

- M8 Studbolts

Left Front Upper

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

12 - 106

50 37 -

4 - 35

24 18 -

17.5 13 -

55 41 -

7 - 62

12 - 106

55 41 -

12 - 106

42 31 -

10 - 89

20 - 177

Page 26

Intake Manifold Support Bracket

to Upper Intake

Manifold - M6

Nuts

Left Front Upper

Intake Manifold Support Bracket

to Cylinder Head

- M6 Bolts

Right Upper Intake Manifold Support Bracket

to Cylinder Head

Cover Studbolts

- M6 Nuts

Right Upper Intake Manifold Support Bracket

to Upper Intake

Manifold - M6

Bolts

Upper Intake

Manifold

Insulation Pad

Brackets - Bolts

Variable Valve

Timing Solenoid

to Cylinder Head

Cover - M5 T25

Wire Harness

Retainer to RH

Cylinder Head -

Bolt

Rear Engine

Mount Bracket

to Manual

Transmission -

Bolts

Rear Engine

Mount Isolator to Rear Engine

Mount Bracket -

Bolts

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

10 - 89

8 - 71

4 - 35

12 - 106

54 40 -

28 21 -

Rear Engine

Mount Bracket

Page 27

Remove the engine cover (1).

to Automatic

Transmission -

4x2

Rear Engine

Mount Bracket

to Automatic

Transmission -

4x4

REMOVAL

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

33 24 -

54 40 -

Fig. 5: Engine Cover Courtesy of CHRYSLER GROUP, LLC

1. Perform the fuel pressure release procedure. Refer to FUEL SYSTEM PRESSURE RELEASE .

2. Disconnect and isolate the negative battery cable.

Page 28

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 6: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers Courtesy of CHRYSLER GROUP, LLC

4. Remove the air cleaner body (1). Refer to BODY, AIR CLEANER, REMOVAL.

Fig. 7: Shifter Shaft, Boots & Bolt Courtesy of CHRYSLER GROUP, LLC

5. If equipped with a manual transmission, remove the shift lever (2). Refer to LEVER, SHIFT,

REMOVAL

Page 29

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 8: Battery Tray Components Courtesy of CHRYSLER GROUP, LLC

6. Remove the battery, Totally Integrated Power Module (TIPM) and battery tray (4). Refer to TRAY, BATTERY, REMOVAL .

Fig. 9: Ground Strap, Bolt, Retainers & Crankshaft Position (CKP) Sensor Courtesy of CHRYSLER GROUP, LLC

7. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

8. Drain the cooling system. Refer to STANDARD PROCEDURE .

9. If required, drain the engine oil. Refer to Engine/Lubrication/OIL - Standard Procedure.

10. Remove the front wheelhouse inner splash shields. Refer to SHIELD, SPLASH, WHEELHOUSE,

REMOVAL

Page 30

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

11. Disconnect the main wire harness from the Crankshaft Position (CKP) sensor (5).

12. Disengage one main wire harness retainer (4) from the engine block and one main wire harness retainer (3) from the oil level indicator.

13. Remove the bolt (2) and ground strap (1) from the engine block.

Fig. 10: Oil Pump Solenoid Electrical Connector & Wire Harness Retainers Courtesy of CHRYSLER GROUP, LLC

14. Disconnect the oil pump solenoid electrical connector (1).

15. Disengage one wire harness retainer (2) from the engine block, one wire harness retainer (3) from the power steering pump mounting bracket and one wire harness retainer (4) from the right engine mount.

Fig. 11: Right And Left Upstream And Downstream Oxygen Sensor Connectors & Bolts Courtesy of CHRYSLER GROUP, LLC

Page 31

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

NOTE: Right catalytic converter shown in illustration, left catalytic converter

similar.

16. Disconnect the right and left upstream (3) and downstream (1) oxygen sensor connectors from the main wire harness.

17. Remove the right and left catalytic converters. Refer to CONVERTER, CATALYTIC, REMOVAL .

Fig. 12: Upper Radiator Hose Courtesy of CHRYSLER GROUP, LLC

18. Lower the vehicle.

19. Remove the upper radiator hose (1) from the engine thermostat housing.

Fig. 13: Heater Core Supply Hose, Heater Core Return Hose & Lower Radiator Hose Courtesy of CHRYSLER GROUP, LLC

Page 32

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

20. Remove the heater core supply hose (1) from the heater core tube assembly.

21. Remove the heater core return hose (2) from the heater core tube assembly.

22. Remove the lower radiator hose (3) from the engine coolant pump housing.

Fig. 14: Heater Core Return Hose, Heater Core Supply Hose, Nuts & Oil Cooler Return Hose Courtesy of CHRYSLER GROUP, LLC

23. Remove the heater core supply hose (2), heater core return hose (1) and oil cooler return hose (4) from the heater core tube assembly.

24. Remove two nuts (3) and the heater core tube assembly from the right upper intake manifold support bracket.

Fig. 15: Upper Intake Manifold & Fasteners Courtesy of CHRYSLER GROUP, LLC

Page 33

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

25. Remove the upper intake manifold (2) and insulator. Refer to MANIFOLD, INTAKE, REMOVAL.

Fig. 16: Fuel Supply Line And Connectors Courtesy of CHRYSLER GROUP, LLC

26. Disconnect the fuel supply hose (2) from the fuel rail. Refer to FITTING, QUICK CONNECT .

Fig. 17: PCV Hose & Valve Courtesy of CHRYSLER GROUP, LLC

27. Remove the PCV hose (1) from the PCV valve (2).

Page 34

32.

Remove the lower power steering pump retaining bolt (2).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 18: Oil Level Indicator & Bolt Courtesy of CHRYSLER GROUP, LLC

28. Remove the bolt (2) and the oil level indicator (1).

Fig. 19: Power Steering Pump Bracket, Bolt & Retainer Courtesy of CHRYSLER GROUP, LLC

29. Remove the accessory drive belt. Refer to BELT, SERPENTINE, REMOVAL .

30. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

31. Disengage the wiring harness routing retainer (3) from the power steering pump bracket (1).

Page 35

36.

Disconnect the field circuit connector (3) from the generator.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 20: Power Steering Return Hose, Supply Line, Retainer & Bolts Courtesy of CHRYSLER GROUP, LLC

33. Lower the vehicle.

34. Disengage the wiring harness routing retainer (2) from the power steering pump bracket.

35. Remove the upper power steering pump bracket retaining bolts (3) and reposition the pump (with bracket).

Fig. 21: Generator Stud, Connector, Retainers & Right Exhaust And Right Intake Variable Valve Timing Solenoid Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

NOTE: Mark the variable valve timing solenoid connectors (5 and 6) with a paint

pen or equivalent so that they may be reinstalled in their original locations.

Page 36

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

37. Remove the B+ terminal from the generator stud (2).

38. Disconnect the right exhaust variable valve timing solenoid electrical connector (5).

39. Disconnect the right intake variable valve timing solenoid electrical connector (6).

40. Disengage the wire harness retainers (1 and 4) from the right cylinder head cover.

Fig. 22: Engine Injection/Ignition Harness, Ignition Coil Electrical Connectors, Retainers, Camshaft Position (CMP) Sensor Connector & Fuel Injector Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

41. Disconnect the main harness from the engine injection/ignition harness (1).

42. Disconnect three fuel injector electrical connectors (5).

43. Disconnect three ignition coil electrical connectors (2).

44. Disconnect the electrical connector (4) from the right Camshaft Position (CMP) sensor.

45. Disengage three main wire harness retainers (3) from the right cylinder head cover.

Page 37

Fig. 23: Ignition Coil Capacitor Electrical Connector & Bolt

51.

Disengage three wire harness retainers (1) from the left cylinder head cover.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Courtesy of CHRYSLER GROUP, LLC

46. Disconnect the electrical connector (2) from the ignition coil capacitor.

47. Remove the bolt (1) and the main wire harness retainer from the rear of the right cylinder head.

Fig. 24: Retainers, A/C Compressor Electrical Connector & Left Intake And Left Exhaust Variable Valve Timing Solenoid Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

NOTE: Mark the variable valve timing solenoid connectors (3 and 4) with a paint

pen or equivalent so that they may be reinstalled in their original locations.

48. Disconnect the A/C compressor electrical connector (2).

49. Disconnect the left exhaust variable valve timing solenoid electrical connector (4).

50. Disconnect the left intake variable valve timing solenoid electrical connector (3).

Page 38

55.

Remove the four A/C compressor mounting bolts (1) and reposition the A/C compressor (2).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 25: Camshaft Position (CMP) Sensor, Retainer & Engine Coolant Temperature (ECT) Sensor Connector Courtesy of CHRYSLER GROUP, LLC

52. Disconnect the Engine Coolant Temperature (ECT) sensor connector (3).

53. Disconnect the left Camshaft Position (CMP) sensor (1).

54. Disengage the main wire harness retainer (2) from the cylinder head cover mounting stud.

Fig. 26: A/C Compressor & Mounting Bolts Courtesy of CHRYSLER GROUP, LLC

Page 39

converter bolts (1) are accessible through the starter mounting. Remove the six torque converter bolts (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 27: Ground Straps & Nut Courtesy of CHRYSLER GROUP, LLC

56. Remove the starter. Refer to STARTER, REMOVAL .

57. Disconnect the power cord from the engine block heater (if equipped).

58. Remove the nut (2) and ground straps (1).

Fig. 28: Torque Converter Bolt Courtesy of CHRYSLER GROUP, LLC

59. Remove the manual transmission, if equipped. Refer to REMOVAL .

60. If equipped with an automatic transmission, rotate the crankshaft in a clockwise direction until the torque

Page 40

Remove the side engine to transmission bolt (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 29: Disengaging Transmission Cooler Line Retainer Courtesy of CHRYSLER GROUP, LLC

61. If equipped with an automatic transmission, disengage the transmission cooler line retainer (1) from the oil pan flange.

Fig. 30: Side Engine-To-Transmission Bolt, Transmission Dust Shield Retaining Bolt & Dust Shield Courtesy of CHRYSLER GROUP, LLC

62. If equipped with an automatic transmission;

 Remove the bolt (2) and the torque converter dust shield (3).



Page 41

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 31: Rubber Plugs & Transmission To Engine Oil Pan Bolts Courtesy of CHRYSLER GROUP, LLC

63. If equipped with an automatic transmission;

 Remove two rubber plugs (1) covering the rear oil seal retainer flange bolts.

 Remove four transmission to the engine oil pan bolts (2 and 3).

Fig. 32: Upper Transmission Engine Bolts Courtesy of CHRYSLER GROUP, LLC

64. If equipped with an automatic transmission, remove four upper transmission to engine bolts (1).

Page 42

67.

Remove the two studbolts (3) and remove the left rear upper intake manifold support bracket (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 33: Engine Mount Heatshield & Bolts Courtesy of CHRYSLER GROUP, LLC

65. Lower the vehicle.

66. Remove the two bolts (2) and the engine mount heatshield (1) from the left engine mount.

Fig. 34: Left Rear Upper Intake Manifold Support Bracket & Studbolts Courtesy of CHRYSLER GROUP, LLC

Page 43

N.m (15 ft. lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 35: Driver Side Engine Lifting Bracket & Bolts Courtesy of CHRYSLER GROUP, LLC

68. Install the Driver Side Engine Lifting Bracket (special tool #10242-1, Brackets, Engine Lifting, Left Side) (1) on the LH cylinder head with bolts (2) provided with the Engine Lifting Bracket. Tighten the bolts to 21 N.m (15 ft. lbs.).

Fig. 36: Passenger Side Engine Lifting Bracket & Bolts Courtesy of CHRYSLER GROUP, LLC

69. Install the Passenger Side Engine Lifting Bracket (special tool #10242-2, Brackets, Engine Lifting, Right Side) (1) on the RH cylinder head with bolts (2) from the Engine Lifting Bracket. Tighten the bolts to 21

Page 44

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 37: Lifting Sling, Engine Lifting Brackets & Engine Hoist Courtesy of CHRYSLER GROUP, LLC

70. Reposition the main wire harness to the rear of the engine compartment.

71. Position a load-leveling lifting sling (2), such as OTC® 4305 Engine Load Leveler or equivalent, between the engine lifting brackets (3) and an engine hoist (1).

Fig. 38: Right Engine Mount & Fasteners Courtesy of CHRYSLER GROUP, LLC

NOTE: Right engine mount shown in illustration, left engine mount similar.

72. If equipped with an automatic transmission, support the transmission with a suitable jack.

73. Loosen both the left and right engine mount nuts (3).

Page 45

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

CAUTION: While slowly separating the engine from the vehicle, constant checks

must be made to assure proper positioning and that no damage to other components or wiring harnesses occur during separation.

74. Carefully remove the engine from the engine bay area.

75. If required, remove the following components for installation on the replacement engine:

 LH engine mount isolator

 RH engine mount isolator

 Accessory drive belt tensioner

 Generator

 Flywheel or flexplate

 Block heater (if equipped)

INSTALLATION

Fig. 39: Upper Intake Manifold & Fasteners Courtesy of CHRYSLER GROUP, LLC

NOTE: If installing a replacement engine, transfer components such as engine mount

isolators, block heater, accessories, heater hoses and tubes to the replacement engine.

1. If required, remove the upper intake manifold (2). Refer to MANIFOLD, INTAKE, REMOVAL.

Page 46

N.m (15 ft. lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 40: Driver Side Engine Lifting Bracket & Bolts Courtesy of CHRYSLER GROUP, LLC

2. Install the Driver Side Engine Lifting Bracket (special tool #10242-1, Brackets, Engine Lifting, Left Side) (1) on the LH cylinder head with bolts (2) provided with the Engine Lifting Bracket. Tighten the bolts to 21 N.m (15 ft. lbs.).

Fig. 41: Passenger Side Engine Lifting Bracket & Bolts Courtesy of CHRYSLER GROUP, LLC

3. Install the Passenger Side Engine Lifting Bracket (special tool #10242-2, Brackets, Engine Lifting, Right Side) (1) on the RH cylinder head with bolts (2) from the Engine Lifting Bracket. Tighten the bolts to 21

Page 47

engine so the weight is resting on the mounting bolts (2).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 42: Lifting Sling, Engine Lifting Brackets & Engine Hoist Courtesy of CHRYSLER GROUP, LLC

4. Position a load-leveling lifting sling (2), such as OTC® 4305 Engine Load Leveler or equivalent, between the engine lifting brackets (3) and an engine hoist (1).

5. Reposition the main wire harness to the rear of the engine compartment.

Fig. 43: Right Engine Mount & Fasteners Courtesy of CHRYSLER GROUP, LLC

NOTE: Right engine mount shown in illustration, left engine mount similar.

6. Position the engine in the vehicle. If equipped with an automatic transmission, align the two locator dowels into the transmission housing.

7. Align the left and right engine mount isolators (1) within the frame mounting brackets and lower the

Page 48

Tighten the bolts to 55 N.m (41 ft. lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

8. Tighten the left and right engine mount nuts (3) to 61 N.m (45 ft. lbs.).

Fig. 44: Engine Mount Heatshield & Bolts Courtesy of CHRYSLER GROUP, LLC

9. Install the engine mount heatshield (1) to the left engine mount with two bolts (2) tightened to 12 N.m (106 in. lbs.).

Fig. 45: Upper Transmission Engine Bolts Courtesy of CHRYSLER GROUP, LLC

10. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

11. Install the manual transmission, if equipped. Refer to INSTALLATION .

12. If equipped with an automatic transmission, install the four upper transmission to engine bolts (1).

Page 49

lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 46: Rubber Plugs & Transmission To Engine Oil Pan Bolts Courtesy of CHRYSLER GROUP, LLC

13. If equipped with an automatic transmission;

 Install four transmission to the engine oil pan bolts (2 and 3) and tighten to 55 N.m (41 ft. lbs.).

 Install two rubber plugs (1) covering the rear oil seal retainer flange bolts.

Fig. 47: Side Engine-To-Transmission Bolt, Transmission Dust Shield Retaining Bolt & Dust Shield Courtesy of CHRYSLER GROUP, LLC

14. If equipped with an automatic transmission;

 Install the side engine to transmission bolt (1). Tighten the bolt to 55 N.m (41 ft. lbs.).

 Install the torque converter dust shield (3) with the bolt (2). Tighten the bolt to 12 N.m (106 in.

Page 50

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 48: Engaging Transmission Cooler Line Retainer Courtesy of CHRYSLER GROUP, LLC

15. If equipped with an automatic transmission, engage the transmission cooler line retainer (1) to the oil pan flange.

Fig. 49: Torque Converter Bolt Courtesy of CHRYSLER GROUP, LLC

16. If equipped with an automatic transmission, rotate the crankshaft in a clockwise direction and install the six torque converter bolts (1) through the starter mounting. Tighten the bolts to 42 N.m (31 ft. lbs.).

Page 51

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 50: Ground Straps & Nut Courtesy of CHRYSLER GROUP, LLC

17. Connect the power cord to the engine block heater (if equipped).

18. Install the ground straps (1) with one nut (2) tightened to 12 N.m (106 in. lbs.).

19. Install the starter. Refer to STARTER, INSTALLATION .

Fig. 51: A/C Compressor & Mounting Bolts Courtesy of CHRYSLER GROUP, LLC

20. Install the A/C compressor (2) onto the engine with four bolts (1) tightened to 28 N.m (21 ft. lbs.).

Page 52

23.

Route the main wire harness on the left side of the engine.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 52: Right And Left Upstream And Downstream Oxygen Sensor Connectors & Bolts Courtesy of CHRYSLER GROUP, LLC

NOTE: Right catalytic converter shown in illustration, left catalytic converter

similar.

21. Install the right and left catalytic converters. Refer to CONVERTER, CATALYTIC, INSTALLATION .

22. Connect the right and left upstream (3) and downstream (1) oxygen sensor connectors to the main wire harness.

Fig. 53: Retainers, A/C Compressor Electrical Connector & Left Intake And Left Exhaust Variable Valve Timing Solenoid Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

Page 53

30.

Engage the main wire harness retainer (2) to the cylinder head cover mounting stud.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

24. Connect the A/C compressor electrical connector (2).

25. Connect the left exhaust variable valve timing solenoid electrical connector (4).

26. Connect the left intake variable valve timing solenoid electrical connector (3).

27. Engage three wire harness retainers (1) to the left cylinder head cover.

Fig. 54: Camshaft Position (CMP) Sensor, Retainer & Engine Coolant Temperature (ECT) Sensor Connector Courtesy of CHRYSLER GROUP, LLC

28. Connect the Engine Coolant Temperature (ECT) sensor connector (3).

29. Connect the left Camshaft Position (CMP) sensor (1).

Page 54

32.

Route the main wire harness on the right side of the engine.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 55: Left Upstream Oxygen Sensor & Left Downstream Oxygen Sensor Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

31. Connect the left upstream oxygen sensor (1) and the left downstream oxygen sensor (2) electrical connectors.

Fig. 56: Generator Stud, Connector, Retainers & Right Exhaust And Right Intake Variable Valve Timing Solenoid Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

Page 55

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

33. Install the B+ terminal to the generator stud (2) and tighten the nut to 11 N.m (97 In. lbs.).

34. Connect the field circuit connector (3) to the generator.

35. Connect the right exhaust variable valve timing solenoid electrical connector (5).

36. Connect the right intake variable valve timing solenoid electrical connector (6).

37. Engage the wire harness retainers (1 and 4) to the right cylinder head cover.

Fig. 57: Engine Injection/Ignition Harness, Ignition Coil Electrical Connectors, Retainers, Camshaft Position (CMP) Sensor Connector & Fuel Injector Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

38. Connect three fuel injector electrical connectors (5).

39. Connect three ignition coil electrical connectors (2).

40. Connect the electrical connector (4) to the right Camshaft Position (CMP) sensor.

41. Connect the main harness to the engine injection/ignition harness (1).

42. Engage three main wire harness retainers (3) to the right cylinder head cover.

Page 56

44.

Secure the main wire harness retainer to the rear of the right cylinder head with the bolt (1) tightened to

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 58: Right Upstream Oxygen Sensor & Right Downstream Oxygen Sensor Electrical Connectors Courtesy of CHRYSLER GROUP, LLC

43. Connect the right upstream oxygen sensor (1) and the right downstream oxygen sensor (2) electrical connectors.

Fig. 59: Ignition Coil Capacitor Electrical Connector & Bolt Courtesy of CHRYSLER GROUP, LLC

Page 57

12 N.m (106 in. lbs.).

49.

Engage the wiring harness routing retainer (3) to the power steering pump bracket (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

45. Connect the electrical connector (2) to the ignition coil capacitor.

Fig. 60: Power Steering Return Hose, Supply Line, Retainer & Bolts Courtesy of CHRYSLER GROUP, LLC

46. Position the power steering pump (with bracket) and install the upper power steering pump bracket retaining bolts (3). Do not tighten at this time.

47. Engage the wiring harness routing retainer (2) to the power steering pump bracket.

Fig. 61: Power Steering Pump Bracket, Bolt & Retainer Courtesy of CHRYSLER GROUP, LLC

48. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

Page 58

steering pump mounting bracket and one wire harness retainer (4) to the right engine mount.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

50. Install the lower power steering pump retaining bolt (2) and tighten all three retaining bolts to 24 N.m (18 ft. lbs.).

51. Install the accessory drive belt. Refer to BELT, SERPENTINE, INSTALLATION .

Fig. 62: Oil Level Indicator & Bolt Courtesy of CHRYSLER GROUP, LLC

52. Install the oil level indicator (1) with the bolt (2) tightened to 12 N.m (106 in. lbs.).

Fig. 63: Oil Pump Solenoid Electrical Connector & Wire Harness Retainers Courtesy of CHRYSLER GROUP, LLC

53. Connect the oil pump solenoid electrical connector (1).

54. Engage one wire harness retainer (2) to the engine block, one wire harness retainer (3) to the power

Page 59

58.

Install the PCV hose (1) to the PCV valve (2).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 64: Ground Strap, Bolt, Retainers & Crankshaft Position (CKP) Sensor Courtesy of CHRYSLER GROUP, LLC

55. Install the ground strap (1) with bolt (2) tightened to 12 N.m (106 in. lbs.).

56. Connect the main wire harness to the Crankshaft Position (CKP) sensor (5).

57. Engage one main wire harness retainer (4) to the engine block and one main wire harness retainer (3) to the oil level indicator.

Fig. 65: PCV Hose & Valve Courtesy of CHRYSLER GROUP, LLC

Page 60

60.

Install the insulator (2) to the two alignment posts (3) on top of the LH cylinder head cover.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 66: Fuel Supply Line And Connectors Courtesy of CHRYSLER GROUP, LLC

59. Connect the fuel supply hose (2) to the fuel rail. Refer to FITTING, QUICK CONNECT .

Fig. 67: Intake Ports, Insulator & Alignment Posts Courtesy of CHRYSLER GROUP, LLC

Page 61

tightened to 12 N.m (106 in. lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 68: Upper Intake Manifold Tightening Sequence Courtesy of CHRYSLER GROUP, LLC

61. Install the upper intake manifold and insulator. Refer to MANIFOLD, INTAKE, INSTALLATION.

Fig. 69: Heater Core Return Hose, Heater Core Supply Hose, Nuts & Oil Cooler Return Hose Courtesy of CHRYSLER GROUP, LLC

62. Position the heater core tube assembly and install the heater core supply hose (2), heater core return hose (1) and oil cooler return hose (4).

63. Secure the heater core tube assembly to the right upper intake manifold support bracket with two nuts (3)

Page 62

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 70: Heater Core Supply Hose, Heater Core Return Hose & Lower Radiator Hose Courtesy of CHRYSLER GROUP, LLC

64. Connect the heater core supply hose (1) to the heater core tube assembly.

65. Connect the heater core return hose (2) to the heater core tube assembly.

66. Install the lower radiator hose (3) to the engine coolant pump housing.

Fig. 71: Upper Radiator Hose Courtesy of CHRYSLER GROUP, LLC

67. Install the upper radiator hose (1) to the engine thermostat housing.

Page 63

INSTALLATION

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 72: Battery Tray Components Courtesy of CHRYSLER GROUP, LLC

68. Install the battery tray (4), Totally Integrated Power Module (TIPM) and battery. Refer to TRAY, BATTERY, INSTALLATION .

69. Install the front wheelhouse inner splash shields. Refer to SHIELD, SPLASH, WHEELHOUSE, INSTALLATION .

Fig. 73: Shifter Shaft, Boots & Bolt Courtesy of CHRYSLER GROUP, LLC

70. If equipped with a manual transmission, install the shift lever (2). Refer to LEVER, SHIFT,

Page 64

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 74: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers Courtesy of CHRYSLER GROUP, LLC

71. Install the air cleaner body (1). Refer to BODY, AIR CLEANER, INSTALLATION.

Fig. 75: Engine Cover Courtesy of CHRYSLER GROUP, LLC

72. If removed, install the oil filter and fill the engine crankcase with the proper oil to the correct level. Refer to Engine/Lubrication/OIL - Standard Procedure.

73. Fill the cooling system. Refer to STANDARD PROCEDURE .

74. Install the engine cover (1).

75. Connect the negative battery cable and tighten nut to 5 N.m (45 in. lbs.).

76. Run the engine until it reaches normal operating temperature. Check cooling system for correct fluid

Page 65

level. Refer to

STANDARD PROCEDURE

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

NOTE: The Cam/Crank Variation Relearn procedure must be performed using the scan

tool anytime there has been a repair/replacement made to a powertrain system, for example: flywheel, valvetrain, camshaft and/or crankshaft sensors or components.

SPECIAL TOOLS

10198 - Holder, Vibration Damper (Originally Shipped In Kit Number(s) 10223.)

10199 - Installer, Crankshaft Front Oil Seal (Originally Shipped In Kit Number(s) 10223.)

10200-1 - Holder, Timing Chain, Left Side 10200-3 - Pin 10202 - Locks, Camshaft/Phaser 10202-1 - Lock, Camshaft/Phaser, Right Side 10202-2 - Lock, Camshaft/Phaser, Left Side 10224 - Adapter, Valve Spring

(Originally Shipped In Kit Number(s) 10223.) 10242-1 - Brackets, Engine Lifting, Left Side

(Originally Shipped In Kit Number(s) 10223.) 10242-2 - Brackets, Engine Lifting, Right Side

(Originally Shipped In Kit Number(s) 10223.) 10255 - Installer, Spark Plug Tube 10256 - Installer, Cam Installer, Cam Sensor/ Spark Plug Tube Seal

(Originally Shipped In Kit Number(s) 10256.) 10368 - Set, Universal Protective Cap 10369 - Holder, Timing Chain 7700-A - Tester, Cooling System 8189 - Guide Pins

(Originally Shipped In Kit Number(s) 8180, 8180CC, 8263, 8263CC.) 8511 - Remover, Seal

(Originally Shipped In Kit Number(s) 8283, 8283CC, 8527, 8527CC, 8575, 8575CC, 9975.) 8514 - Pins, Tensioner

(Originally Shipped In Kit Number(s) 8283, 8283CC, 8527, 8527CC, 8575, 8575CC, 9975.) 8534B - Fixture, Driveline Support

(Originally Shipped In Kit Number(s) 8534, 8534B, 8849, 9565.) C-119 - Cylinder Indicator C-3292A - Gauge, Pressure C-3339A - Set, Dial Indicator

(Originally Shipped In Kit Number(s) 9202.) C-3422-D - Compressor, Valve Spring

Page 66

Remove the engine cover (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

C-3685-A - Bloc-Chek Kit C-385 - Compressor, Piston MD998772A - Compressor, Valve Spring

(Originally Shipped In Kit Number(s) 8678, 8853, 8854.)

AIR INTAKE SYSTEM

AIR CLEANER

REMOVAL

Fig. 76: Engine Cover Courtesy of CHRYSLER GROUP, LLC

Page 67

Remove any dirt or debris from the bottom of the air cleaner housing.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 77: Air Cleaner Housing Cover Latches Courtesy of CHRYSLER GROUP, LLC

2. Release the four air cleaner housing cover latches (1).

Fig. 78: Air Cleaner Housing Cover & Air Cleaner Element Courtesy of CHRYSLER GROUP, LLC

3. Lift the cover (1) and remove the air cleaner element (2).

CAUTION: Do not use compressed air to clean out the air cleaner housing

without first covering the air inlet to the throttle body. Dirt or foreign objects could enter the intake manifold causing engine damage.

Page 68

INSTALLATION

Seat the cover onto the housing and secure the four housing cover latches (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 79: Air Cleaner Housing Cover & Air Cleaner Element Courtesy of CHRYSLER GROUP, LLC

1. Install the air cleaner element (2) into the air cleaner housing.

Fig. 80: Air Cleaner Housing Cover Latches Courtesy of CHRYSLER GROUP, LLC

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2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 81: Engine Cover Courtesy of CHRYSLER GROUP, LLC

3. Install the engine cover (1).

BODY, AIR CLEANER

REMOVAL

Fig. 82: Engine Cover Courtesy of CHRYSLER GROUP, LLC

1. Disconnect and isolate the negative battery cable.

2. Remove the engine cover (1).

Page 70

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 83: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers Courtesy of CHRYSLER GROUP, LLC

3. Disconnect the electrical connector (3) from the Inlet Air Temperature (IAT) sensor.

4. Loosen the clamp (4) at the throttle body.

5. Disconnect the fresh air makeup hose (2) from the air cleaner body.

6. Disengage the coolant hose from the two retainers (6).

7. Remove the two bolts (5) from the air inlet hose.

8. Disengage the air inlet hose from the throttle body and pull the air cleaner body (1) straight up off of the three locating pins.

INSTALLATION

Page 71

Fig. 84: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Courtesy of CHRYSLER GROUP, LLC

1. Install the air cleaner body (1) straight down on the three locating pins while engaging the air inlet hose to the throttle body.

2. Install the two bolts (5) to the air inlet hose and tighten to 12 N.m (106 in. lbs.).

3. Engage the coolant hose to the two retainers (6).

4. Install the fresh air makeup hose (2) to the air cleaner body.

5. Tighten the clamp (4) at the throttle body to 4 N.m (35 in. lbs.).

6. Connect the electrical connector (3) to the Inlet Air Temperature (IAT) sensor.

Fig. 85: Engine Cover Courtesy of CHRYSLER GROUP, LLC

7. Install the engine cover (1).

8. Connect the negative battery cable and tighten nut to 5 N.m (45 in. lbs.).

CYLINDER HEAD

DESCRIPTION

Page 72

Coolant foaming

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 86: Aluminum Cylinder Head Courtesy of CHRYSLER GROUP, LLC

The 3.6L aluminum cylinder heads are a unique design with left and right castings. The exhaust manifolds are integrated into the cylinder heads. The cylinder head features four valves per cylinder with pressed in powdered metal valve guides. The valve guides are not serviceable. The DOHC valvetrain uses roller rocker arms with hydraulic lifters. The cylinder head's camshaft bearing caps are made of powdered metal and the location and direction of each cap is marked on the side of the caps. The spark plug tubes are pressed into the cylinder heads and sealed in place. The tubes are a thin wall design and caution must be taken when working in the spark plug tube area.

DIAGNOSIS AND TESTING

CYLINDER HEAD GASKET

A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent water jacket.

Possible indications of the cylinder head gasket leaking between adjacent cylinders are:

 Loss of engine power

 Engine misfiring

 Poor fuel economy

Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:

 Engine overheating

 Loss of coolant

 Excessive steam (white smoke) emitting from exhaust



Page 73

CYLINDER

-TO-

CYLINDER LEAKAGE TEST

CHEMICAL TEST METHOD

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

To determine if an engine cylinder head gasket is leaking between adjacent cylinders, follow the procedures in Cylinder Compression Pressure Test. Refer to CYLINDER COMPRESSION PRESSURE LEAKAGE. An engine cylinder head gasket leaking between adjacent cylinders will result in approximately a 50 - 70% reduction in compression pressure.

CYLINDER-TO-WATER JACKET LEAKAGE TEST

WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH

COOLANT PRESSURE CAP REMOVED.

VISUAL TEST METHOD

With the engine cool, remove the coolant pressure cap. Start the engine and allow it to warm up until thermostat opens.

If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.

COOLING SYSTEM TESTER METHOD

Fig. 87: Cooling System Pressure Tester - 7700-A Courtesy of CHRYSLER GROUP, LLC

WARNING: WITH COOLING SYSTEM TESTER IN PLACE, PRESSURE WILL BUILD UP

FAST. EXCESSIVE PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE POINT. NEVER PERMIT PRESSURE TO EXCEED 138 kPa (20 psi).

Install Cooling System Tester (special tool #7700-A, Tester, Cooling System) or equivalent to pressure cap neck. Start the engine and observe the tester's pressure gauge. If gauge pulsates with every power stroke of a cylinder a combustion pressure leak is evident.

Page 74

LEFT

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 88: Bloc-Chek-Kit - C-3685-A Courtesy of CHRYSLER GROUP, LLC

Combustion leaks into the cooling system can also be checked by using Bloc-Chek Kit (special tool #C-3685-A, Bloc-Chek Kit) or equivalent. Perform test following the procedures supplied with the tool kit.

HYDRAULIC LASH ADJUSTER

A tappet-like noise may be produced from several items. Check the following items.

1. Engine oil level too high or too low. This may cause aerated oil to enter the adjusters and cause them to be spongy.

2. Insufficient running time after rebuilding cylinder head. Low speed running up to 1 hour may be required.

3. Turn engine off and let set for a few minutes before restarting. Repeat this several times after engine has reached normal operating temperature.

4. Low oil pressure.

5. The oil passage in cylinder head gasket or the oil passage to the cylinder head is plugged with debris.

6. Air ingested into oil due to broken or cracked oil pump pick up.

7. Worn valve guides.

8. Rocker arm ears contacting valve spring retainer.

9. Rocker arm loose, adjuster stuck or at maximum extension and still leaves lash in the system.

10. Oil leak or excessive cam bore wear in cylinder head.

11. Faulty lash adjuster.

a. Check lash adjusters for "sponginess" while installed in cylinder head and cam on camshaft at base circle.

Depress part of rocker arm over adjuster. Normal adjusters should feel firm when pressed quickly. When pressed very slowly, lash adjusters should collapse.

b. Remove suspected lash adjusters, and replace.

c. Before installation, make sure adjusters are full of oil. This can be verified by little plunger travel when

lash adjuster is depressed quickly.

REMOVAL

Page 75

Remove the engine cover (1).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 89: Magnetic Timing Wheels Courtesy of CHRYSLER GROUP, LLC

CAUTION: The magnetic timing wheels (1) must not come in contact with magnets

(pickup tools, trays, etc.) or any other strong magnetic field. This will destroy the timing wheels ability to correctly relay camshaft position to the camshaft position sensor.

Fig. 90: Engine Cover Courtesy of CHRYSLER GROUP, LLC

1. Perform the fuel pressure release procedure. Refer to FUEL SYSTEM PRESSURE RELEASE .

2. Disconnect and isolate the negative battery cable.

Page 76

Drain the engine oil. Refer to

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 91: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers Courtesy of CHRYSLER GROUP, LLC

4. Remove the air cleaner body (1). Refer to BODY, AIR CLEANER, REMOVAL.

Fig. 92: Right And Left Upstream And Downstream Oxygen Sensor Connectors & Bolts Courtesy of CHRYSLER GROUP, LLC

NOTE: Right catalytic converter shown in illustration, left catalytic converter

similar.

5. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

6. Drain the cooling system. Refer to STANDARD PROCEDURE .

Engine/Lubrication/OIL - Standard Procedure

Page 77

REMOVAL

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2012 ENGINE 3.6L - Service Information - Wrangler

8. Disconnect the left upstream (3) and downstream (1) oxygen sensor connectors from the main wire harness.

9. Remove the left catalytic converter. Refer to CONVERTER, CATALYTIC, REMOVAL .

Fig. 93: Upper Intake Manifold & Fasteners Courtesy of CHRYSLER GROUP, LLC

10. Lower the vehicle.

11. Remove the upper and lower intake manifolds (2) and insulator. Refer to MANIFOLD, INTAKE, REMOVAL.

12. Remove the right and left cylinder head covers. Refer to COVER(S), CYLINDER HEAD,

Fig. 94: Drive Belt Tensioners & Assembly With Drive Belt Routing Courtesy of CHRYSLER GROUP, LLC

Page 78

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2012 ENGINE 3.6L - Service Information - Wrangler

13. Remove the accessory drive belt (7). Refer to BELT, SERPENTINE, REMOVAL .

Fig. 95: A/C Compressor & Mounting Bolts Courtesy of CHRYSLER GROUP, LLC

14. Remove the four bolts (1) and reposition the A/C compressor (2).

Fig. 96: Ignition Coil Capacitor Electrical Connector Courtesy of CHRYSLER GROUP, LLC

15. Disconnect the ignition coil capacitor electrical connector (1).

Page 79

19.

Lower the vehicle.

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 97: Left Rear Upper Intake Manifold Support Bracket & Studbolts Courtesy of CHRYSLER GROUP, LLC

16. Remove the two studbolts (3) and remove the left rear upper intake manifold support bracket (1).

Fig. 98: Piston Extension & RH Cam Chain Tensioner Courtesy of CHRYSLER GROUP, LLC

17. Remove the spark plugs. Refer to SPARK PLUG, REMOVAL .

18. Remove the upper oil pan, crankshaft vibration damper and engine timing cover. Refer to COVER(S), ENGINE TIMING, REMOVAL.

NOTE: Take this opportunity to measure timing chain wear. Refer to Engine/Valve

Timing - Standard Procedure.

Page 80

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 99: Rotating Crankshaft Clockwise To Position No. 1 Piston At TDC On Exhaust Stroke Courtesy of CHRYSLER GROUP, LLC

CAUTION: When aligning timing marks, always rotate engine by turning the

crankshaft. Failure to do so will result in valve and/or piston damage.

20. Rotate the crankshaft CW to place the number one piston at TDC on the exhaust stroke by aligning the dimple (4) on the crankshaft with the block/bearing cap junction (5). The left side cam phaser arrows (2) should point toward each other and be parallel to the valve cover sealing surface (3). The right side cam phaser arrows (7) should point away from each other and the scribe lines (9) should be parallel to the valve cover sealing surface (8).

CAUTION: Always reinstall timing chains so that they maintain the same

direction of rotation. Inverting a previously run chain on a previously run sprocket will result in excessive wear to both the chain and sprocket.

21. Mark the direction of rotation on the timing chain using a paint pen or equivalent to aid in reassembly.

Page 81

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 100: Resetting Left Cam Chain Tensioner Courtesy of CHRYSLER GROUP, LLC

CAUTION: When the timing chains are removed and the cylinder heads are still

installed, DO NOT rotate the camshafts or crankshaft without first locating the proper crankshaft position. Failure to do so will result in valve and/or piston damage.

22. Reset the LH cam chain tensioner by lifting the pawl (1), pushing back the piston (2) and installing Tensioner Pin (special tool #8514, Pins, Tensioner) (3). Refer to Engine/Valve Timing - Standard

Procedure.

Fig. 101: Phaser Timing Marks, Oil Control Valves & LH Camshaft Phaser Lock Courtesy of CHRYSLER GROUP, LLC

NOTE: Minor rotation of a camshaft (a few degrees) may be required to install the

Page 82

30.

Remove two T30 bolts (4) and the LH cam chain guide (2).

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2012 ENGINE 3.6L - Service Information - Wrangler

camshaft phaser lock.

23. Install the LH Camshaft Phaser Lock (special tool #10202, Locks, Camshaft/Phaser) (4).

24. Loosen both the intake oil control valve (6) and exhaust oil control valve (2).

25. Remove the LH Camshaft Phaser Lock (special tool #10202, Locks, Camshaft/Phaser) (4).

26. Remove the oil control valve (2) from the left side exhaust cam phaser and pull the phaser off of the camshaft.

27. Remove the oil control valve (6) from the left side intake cam phaser and pull the phaser off of the camshaft.

Fig. 102: Left Cam Chain Tensioner, Arm, Guide & Bolts Courtesy of CHRYSLER GROUP, LLC

28. Remove the LH cam chain tensioner arm (1).

29. Remove two T30 bolts (6) and the LH cam chain tensioner (5).

Page 83

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 103: Cylinder Head Retaining Bolt Removal Sequence - Left Courtesy of CHRYSLER GROUP, LLC

31. Remove the left camshafts. Refer to CAMSHAFT, ENGINE, REMOVAL.

NOTE: If the rocker arms are to be reused, identify their positions so that they can

be reassembled into their original locations.

32. Remove the rocker arms. Refer to ROCKER ARM, VALVE, REMOVAL.

NOTE: If the hydraulic lifters are to be reused, identify their positions so that they

can be reassembled into their original locations.

33. If required, remove the hydraulic lifters. Refer to LIFTER(S), HYDRAULIC, REMOVAL.

34. Using the sequence shown in illustration, remove the cylinder head retaining bolts.

Page 84

Fig. 104: Head Gasket & Locating Dowels

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2012 ENGINE 3.6L - Service Information - Wrangler

Courtesy of CHRYSLER GROUP, LLC

NOTE: Right head gasket shown in illustration, left head gasket similar.

WARNING: The multi-layered steel head gaskets have very sharp edges that

could cause personal injury if not handled carefully.

NOTE: The head gasket (1) crimps the locating dowels (2) and the dowels may

pull out of the engine block when the head gasket is removed.

35. Remove the cylinder head and gasket (1). Discard the gasket.

CAUTION: Do not lay the cylinder head on its gasket sealing surface, due to the

design of the cylinder head gasket, any distortion to the cylinder head sealing surface may prevent the gasket from properly sealing resulting in leaks.

Fig. 105: Ignition Coil Capacitor, Bolt & Engine Coolant Temperature (ECT) Sensor Courtesy of CHRYSLER GROUP, LLC

36. If required, remove the Engine Coolant Temperature (ECT) sensor (3).

37. If required, remove the bolt (2) and the ignition coil capacitor (1).

RIGHT

Page 85

Remove the engine cover (1).

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 106: Magnetic Timing Wheels Courtesy of CHRYSLER GROUP, LLC

CAUTION: The magnetic timing wheels (1) must not come in contact with magnets

(pickup tools, trays, etc.) or any other strong magnetic field. This will destroy the timing wheels ability to correctly relay camshaft position to the camshaft position sensor.

Fig. 107: Engine Cover Courtesy of CHRYSLER GROUP, LLC

1. Perform the fuel pressure release procedure. Refer to FUEL SYSTEM PRESSURE RELEASE .

2. Disconnect and isolate the negative battery cable.

Page 86

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 108: Air Cleaner Body, Fresh Air Makeup Hose, Electrical Connector, Clamp, Bolts & Retainers Courtesy of CHRYSLER GROUP, LLC

4. Remove the air cleaner body (1). Refer to BODY, AIR CLEANER, REMOVAL.

Fig. 109: Battery Tray Components Courtesy of CHRYSLER GROUP, LLC

5. Remove the battery, Totally Integrated Power Module (TIPM) and battery tray (4). Refer to TRAY,

BATTERY, REMOVAL

Page 87

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 110: Right And Left Upstream And Downstream Oxygen Sensor Connectors & Bolts Courtesy of CHRYSLER GROUP, LLC

6. Raise and support the vehicle. Refer to HOISTING, STANDARD PROCEDURE .

7. Drain the cooling system. Refer to STANDARD PROCEDURE .

8. Drain the engine oil. Refer to Engine/Lubrication/OIL - Standard Procedure.

9. Disconnect the left upstream (3) and downstream (1) oxygen sensor connectors from the main wire harness.

10. Remove the right catalytic converter. Refer to CONVERTER, CATALYTIC, REMOVAL .

Fig. 111: Power Steering Pump Bracket, Bolt & Retainer Courtesy of CHRYSLER GROUP, LLC

11. Disengage the wiring harness routing retainer (3) from the power steering pump bracket (1).

12. Remove the lower power steering pump retaining bolt (2).

Page 88

16.

Remove the accessory drive belt (7). Refer to

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 112: Upper Intake Manifold & Fasteners Courtesy of CHRYSLER GROUP, LLC

13. Lower the vehicle.

14. Remove the upper and lower intake manifolds (2) and insulator. Refer to MANIFOLD, INTAKE,

REMOVAL.

Fig. 113: Drive Belt Tensioners & Assembly With Drive Belt Routing Courtesy of CHRYSLER GROUP, LLC

15. Remove the right and left cylinder head covers. Refer to COVER(S), CYLINDER HEAD, REMOVAL.

BELT, SERPENTINE, REMOVAL

Page 89

20.

Remove the bolt (1) and the main wire harness retainer from the rear of the right cylinder head.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 114: Power Steering Return Hose, Supply Line, Retainer & Bolts Courtesy of CHRYSLER GROUP, LLC

17. Disengage the wiring harness routing retainer (2) from the power steering pump bracket.

18. Remove the upper power steering pump bracket retaining bolts (3) and reposition the pump (with bracket).

Fig. 115: Ignition Coil Capacitor Electrical Connector & Bolt Courtesy of CHRYSLER GROUP, LLC

19. Disconnect the electrical connector (2) from the ignition coil capacitor.

Page 90

23.

Lower the vehicle.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 116: Piston Extension & RH Cam Chain Tensioner Courtesy of CHRYSLER GROUP, LLC

21. Remove the spark plugs. Refer to SPARK PLUG, REMOVAL .

22. Remove the oil pan, crankshaft vibration damper and engine timing cover. Refer to COVER(S), ENGINE TIMING, REMOVAL.

NOTE: Take this opportunity to measure timing chain wear. Refer to Engine/Valve

Timing - Standard Procedure.

Page 91

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 117: Rotating Crankshaft Clockwise To Position No. 1 Piston At TDC On Exhaust Stroke Courtesy of CHRYSLER GROUP, LLC

CAUTION: When aligning timing marks, always rotate engine by turning the

crankshaft. Failure to do so will result in valve and/or piston damage.

24. Rotate the crankshaft CW to place the number one piston at TDC on the exhaust stroke by aligning the dimple (4) on the crankshaft with the block/bearing cap junction (5). The left side cam phaser arrows (2) should point toward each other and be parallel to the valve cover sealing surface (3). The right side cam phaser arrows (7) should point away from each other and the scribe lines (9) should be parallel to the valve cover sealing surface (8).

CAUTION: Always reinstall timing chains so that they maintain the same

direction of rotation. Inverting a previously run chain on a previously run sprocket will result in excessive wear to both the chain and sprocket.

25. Mark the direction of rotation on the timing chain using a paint pen or equivalent to aid in reassembly.

Page 92

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 118: Resetting Right Cam Chain Tensioner Courtesy of CHRYSLER GROUP, LLC

CAUTION: When the timing chains are removed and the cylinder heads are still

installed, DO NOT rotate the camshafts or crankshaft without first locating the proper crankshaft position. Failure to do so will result in valve and/or piston damage.

26. Reset the RH cam chain tensioner by pushing back the tensioner piston and installing Tensioner Pin (special tool #8514, Pins, Tensioner) (1).

Fig. 119: Phaser Timing Marks, Oil Control Valves & RH Camshaft Phaser Lock Courtesy of CHRYSLER GROUP, LLC

NOTE: Minor rotation of a camshaft (a few degrees) may be required to install the

camshaft phaser lock.

Page 93

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2012 ENGINE 3.6L - Service Information - Wrangler

27. Install the RH Camshaft Phaser Lock (special tool #10202, Locks, Camshaft/Phaser) (5).

28. Loosen both the intake oil control valve (2) and exhaust oil control valve (7).

29. Remove the RH Camshaft Phaser Lock (special tool #10202, Locks, Camshaft/Phaser) (5).

30. Remove the oil control valve (2) from the right side intake cam phaser and pull the phaser off of the camshaft.

31. Remove the oil control valve (7) from the right side exhaust cam phaser and pull the phaser off of the camshaft.

Fig. 120: Right Cam Chain Tensioner, Arm, Guide & Bolts Courtesy of CHRYSLER GROUP, LLC

32. Remove the RH cam chain tensioner arm (6).

33. Remove two T30 bolts (4) and the RH cam chain tensioner (3).

34. Remove three T30 bolts (2) and the RH cam chain guide (1).

Page 94

Fig. 121: Cylinder Head Retaining Bolt Removal Sequence

Right

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Courtesy of CHRYSLER GROUP, LLC

35. Remove the right camshafts. Refer to CAMSHAFT, ENGINE, REMOVAL.

NOTE: If the rocker arms are to be reused, identify their positions so that they can

be reassembled into their original locations.

36. Remove the rocker arms. Refer to ROCKER ARM, VALVE, REMOVAL.

NOTE: If the hydraulic lifters are to be reused, identify their positions so that they

can be reassembled into their original locations.

37. If required, remove the hydraulic lifters. Refer to LIFTER(S), HYDRAULIC, REMOVAL.

38. Using the sequence shown in illustration, remove the cylinder head retaining bolts.

Fig. 122: Head Gasket & Locating Dowels Courtesy of CHRYSLER GROUP, LLC

WARNING: The multi-layered steel head gaskets have very sharp edges that

could cause personal injury if not handled carefully.

NOTE: The head gasket (1) crimps the locating dowels (2) and the dowels may

pull out of the engine block when the head gasket is removed.

39. Remove the cylinder head and gasket. Discard the gasket.

CAUTION: Do not lay the cylinder head on its gasket sealing surface, due to the

design of the cylinder head gasket, any distortion to the cylinder

Page 95

Clean out the cylinder head bolt holes in the engine block.

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2012 ENGINE 3.6L - Service Information - Wrangler

head sealing surface may prevent the gasket from properly sealing resulting in leaks.

Fig. 123: Ignition Coil Capacitor & Bolt Courtesy of CHRYSLER GROUP, LLC

40. If required, remove the bolt (2) and the ignition coil capacitor (1).

CLEANING

CAUTION: When cleaning cylinder head and cylinder block surfaces, DO NOT use a

metal scraper because the surfaces could be cut or ground. Use ONLY a wooden or plastic scraper.

To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.

NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.

1. Remove all gasket material from cylinder head and block. Refer to Engine - Standard Procedure. Be careful not to gouge or scratch the aluminum head sealing surface.

2. Clean all engine oil passages.

CAUTION: Non-compressible debris such as oil, coolant or RTV sealants that

are not removed from bolt holes can cause the aluminum casting to crack when tightening the bolts.

Page 96

INSPECTION

LEFT

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 124: Checking Cylinder Head Flatness Courtesy of CHRYSLER GROUP, LLC

1. Check cylinder head warpage with a straight edge (2) and feeler gauge (1).

2. Cylinder head must be flat within specification. Refer to Engine - Specifications.

3. Verify that the valve tappets move freely in theirs bores and that they have been rotating.

4. Inspect camshaft bearing journals for scoring.

5. Remove carbon and varnish deposits from inside of valve guides with a reliable guide cleaner.

6. Inspect the following components and verify that they are within specification. Refer to Engine - Specifications.

 Camshafts

 Valve Tappets

 Springs

 Valve Seats

 Valve Guides

 Valves

INSTALLATION

Page 97

If removed, install the ignition coil capacitor (1) with a M6 bolt (2) tightened to 10 N.m (89 in. lbs.).

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 125: Magnetic Timing Wheels Courtesy of CHRYSLER GROUP, LLC

CAUTION: The magnetic timing wheels (1) must not come in contact with magnets

(pickup tools, trays, etc.) or any other strong magnetic field. This will destroy the timing wheels ability to correctly relay camshaft position to the camshaft position sensor.

Fig. 126: Ignition Coil Capacitor, Bolt & Engine Coolant Temperature (ECT) Sensor Courtesy of CHRYSLER GROUP, LLC

1. If removed, install the Engine Coolant Temperature (ECT) sensor (4) and tighten to 11 N.m (97 in. lbs.).

Page 98

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2012 ENGINE 3.6L - Service Information - Wrangler

Fig. 127: Checking Cylinder Head Bolts For Stretching (Necking) Courtesy of CHRYSLER GROUP, LLC

CAUTION: The cylinder head bolts are tightened using a torque plus angle

procedure. The bolts must be examined BEFORE reuse. If the threads are necked down the bolts must be replaced.

NOTE: Typical cylinder head bolt shown in illustration.

3. Check cylinder head bolts for necking by holding a scale or straight edge against the threads. If all the threads do not contact the scale (2) the bolt must be replaced.

Fig. 128: Head Gasket & Locating Dowels Courtesy of CHRYSLER GROUP, LLC

NOTE: Right head gasket shown in illustration, left head gasket similar.

CAUTION: When cleaning cylinder head and cylinder block surfaces, DO NOT

use a metal scraper because the surfaces could be cut or ground. Use ONLY a wooden or plastic scraper.

Page 99

angle method. Tighten according to the following torque values:

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

4. Clean and prepare the gasket sealing surfaces of the cylinder head and block. Refer to Engine - Standard Procedure.

CAUTION: Non-compressible debris such as oil, coolant or RTV sealants that

are not removed from bolt holes can cause the aluminum casting to crack when tightening the bolts.

5. Clean out the cylinder head bolt holes in the engine block.

WARNING: The multi-layered steel head gaskets have very sharp edges that

could cause personal injury if not handled carefully.

CAUTION: The cylinder head gaskets are not interchangeable between the left

and right cylinder heads and are clearly marked (3) with "R" for right and "L" for left.

6. Position the new cylinder head gasket (1) on the locating dowels (2).

Fig. 129: Cylinder Head Retaining Bolt Tightening Sequence - Left Courtesy of CHRYSLER GROUP, LLC

7. Position the cylinder head onto the cylinder block. Make sure the cylinder head seats fully over the locating dowels.

NOTE: Do not apply any additional oil to the bolt threads.

8. Install the eight head bolts finger tight.

9. Tighten the cylinder head bolts in the sequence shown in illustration, following this 9 step torque plus

Page 100

12.

Rotate the camshafts CW to TDC by positioning the alignment holes (1) vertically.

2012 Jeep Wrangler Sport S

2012 ENGINE 3.6L - Service Information - Wrangler

 Step 1: All to 30 N.m (22 ft. lbs.)

 Step 2: All to 45 N.m (33 ft. lbs.)

 Step 3: All + 75° Turn Do not use a torque wrench for this step.

 Step 4: All + 50° Turn Do not use a torque wrench for this step.

 Step 5: Loosen all fasteners in reverse of sequence shown in illustration

 Step 6: All to 30 N.m (22 ft. lbs.)

 Step 7: All to 45 N.m (33 ft. lbs.)

 Step 8: All + 70° Turn Do not use a torque wrench for this step.

 Step 9: All + 70° Turn Do not use a torque wrench for this step.

Fig. 130: Positioning Camshaft Alignment Holes Vertically Courtesy of CHRYSLER GROUP, LLC

NOTE: If the hydraulic lifters are being reused, reassemble them into their original

locations.

10. If removed, install the hydraulic lifters. Refer to LIFTER(S), HYDRAULIC, INSTALLATION.

NOTE: If the rocker arms are being reused, reassemble them into their original

locations.

11. Install the rocker arms and camshafts. Refer to CAMSHAFT, ENGINE, INSTALLATION.

jeep Engine Engine

Specifications and Main Features

Frequently Asked Questions

User Manual