Subaru Impreza 2004 Service Guide

Maintenance and service

Maintenance schedule

Maintenance and service

Maintenance precautions

The scheduled maintenance items required to be serviced at regular intervals are shown in the “Warranty and Maintenance Booklet”.

For details of your maintenance schedule, read the separate “Warranty and Maintenance Booklet”.

When maintenance and service are required, it is recommended that all work be done by an authorized SUBARU dealer.

If you perform maintenance and service by yourself, you should familiarize yourself with the information provided in this section on general maintenance and service for your SUBARU.

Incorrect or incomplete service could cause improper or unsafe vehicle operation. Any problems caused by improper maintenance and service performed by you are not eligible for warranty coverage.

" Testing of an All-Wheel Drive vehicle must NEVER be performed on a single two-wheel dynamometer or similar apparatus. Attempting to do so will result in transmission damage and in uncontrolled vehicle movement and may cause an accident or injuries to persons nearby. " Always select a safe area when performing maintenance on your vehicle. " Always be very careful to avoid injury when working on the vehicle. Remember that some of

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Maintenance and service

the materials in the vehicle may be hazardous if improperly used or handled, for example, battery acid. " Your vehicle should only be serviced by persons fully competent to do so. Serious personal injury may result to persons not experienced in servicing vehicles. " Always use the proper tools and make certain that they are well maintained. " Never get under the vehicle supported only by a jack. Always use a safety stands to support the vehicle. " Never keep the engine running in a poorly ventilated area, such as a garage or other closed areas. " Do not smoke or allow open flames around the fuel or battery. This will cause a fire. " Because the fuel system is under pressure, replacement of the fuel filter should be performed only by your SUBARU dealer. " Wear adequate eye protection to guard against getting oil or fluids in your eyes. If something does get in your eyes, thoroughly wash them out with clean water. " Do not tamper with the wiring of the SRS airbag system or seatbelt pretensioner system, or attempt to take its connectors apart, as that

may activate the system or it can render it inoperative. The wiring and connectors of these systems are yellow for easy identification. NEVER use a circuit tester for these wiring. If your SRS airbag or seatbelt pretensioner needs service, consult your nearest SUBARU dealer.

! Before checking or servicing in the en-

gine compartment

" Always stop the engine and set the parking brake firmly to prevent the vehicle from moving. " Always let the engine cool down. Engine parts become very hot when the engine is running and remain hot for some time after the engine is stopped. " Do not spill engine oil, engine coolant, brake fluid or any other fluid on hot engine components. This may cause a fire. " Always remove the key from the ignition switch. When the ignition switch is in the “ON” position, the cooling fan may operate suddenly

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Maintenance and service

even when the engine is stopped.

! When you do checking or servicing in

the engine compartment while the engine is running

A running engine can be dangerous. Keep your fingers, hands, clothing, hair and tools away from the cooling fan, belts and any other moving engine parts. Removing rings, watches and ties is advisable.

Engine hood

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To open the hood:

1. If the wiper blades are lifted off the windshield, return them to their original positions.

2. Pull the hood release knob under the instrument panel.

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Maintenance and service

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3. Release the secondary hood release located under the front grille by moving the lever toward the left.

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Lift up the hood, release the hood prop from its retainer and put the end of the hood prop into the slot in the hood.

To close the hood:

All models except WRX and WRX-STi:

1. Lift the hood slightly and remove the hood prop from the slot in the hood and return the prop to its retainer.

2. Lower the hood until it approaches about 6 in. (15

cm) from the closed position and let it drop.

WRX and WRX-STi:

1. Lift the hood slightly and remove the hood prop

from the slot in the hood and return the prop to its retainer.

2. Lower the hood until it approaches about 12 in. (30 cm) from the closed position and let it drop.

After closing the hood, be sure the hood is securely locked.

If this does not close the hood, release it from a slightly higher position. Do not push the hood forcibly to close it. It could deform the metal.

Always check that the hood is properly locked before you start driving. If it is not, it might fly open while the vehicle is moving and block your view, which may cause an accident and serious bodily injury.

Maintenance and service

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Maintenance and service

Engine compartment overview

! 2.5 liter model

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8910111213

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1) Manual transmission oil level gauge (MT) (page 11-28) or Differential gear oil level gauge (AT) (page 11-33)

2) Air cleaner element (page 11-

23)

3) Clutch fluid reservoir (page 11-

38)

4) Automatic transmission fluid level gauge (page 11-31)

5) Brake fluid reservoir (page 11-

37)

6) Windshield washer tank (page 11-54)

7) Fuse box (page 11-60)

8) Battery (page 11-58)

9) Engine oil filler cap (page 11-11)

10) Engine coolant reservoir (page 11-19)

11) Radiator cap (page 11-19)

12) Engine oil level gauge (page 11-

11)

13) Power steering fluid reservoir (page 11-36)

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Maintenance and service

! 2.0 liter (Turbo) model

13 12 11 10 9 8

1) Manual transmission oil level gauge (MT) (page 11-28) or Dif-

34 5 6 712

ferential gear oil level gauge (AT) (page 11-33)

2) Air cleaner element (page 11-

23)

3) Clutch fluid reservoir (page 11-

38)

4) Automatic transmission fluid level gauge (page 11-31)

5) Brake fluid reservoir (page 11-

37)

6) Windshield washer tank (page 11-54)

7) Fuse box (page 11-60)

8) Battery (page 11-58)

9) Engine oil filler cap (page 11-11)

10) Engine coolant reservoir (page 11-19)

11) Engine oil level gauge (page 11-

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11)

12) Radiator cap (page 11-19)

13) Power steering fluid reservoir (page 11-36)

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Maintenance and service

! 2.5 liter (Turbo) model

12 11 10 9 8

34 5 6

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1) Manual transmission oil level gauge (MT) (page 11-28)

2) Air cleaner element (page 11-

23)

3) Clutch fluid reservoir (page 11-

38)

4) Brake fluid reservoir (page 11-

37)

5) Windshield washer tank (page 11-54)

6) Fuse box (page 11-60)

7) Battery (page 11-58)

8) Engine oil filler cap (page 11-11)

9) Engine coolant reservoir (page 11-19)

10) Engine oil level gauge (page 11-

11)

11) Radiator cap (page 11-19)

12) Power steering fluid reservoir (page 11-36)

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Engine oil

! Checking the oil level

Check the engine oil level at each fuel stop.

1. Park the vehicle on a level surface and stop the engine.

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2. Pull out the dipstick, wipe it clean, and insert it again.

3. Be sure the dipstick is correctly inserted until it stops with the graphic symbol on its top appearing as shown in the illustration.

Maintenance and service

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2.5-liter turbo models

1) Notch

2) Upper level

3) Lower level

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Maintenance and service

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2.5-liter and 2.0-liter turbo models

1) Notch

2) Upper level

3) Lower level

4. Pull out the dipstick again and check the oil level on it. If it is below the lower level, add oil to bring the level up to the upper level.

" Use only engine oil with the recommended grade and viscosity. " Be careful not to spill engine oil when adding it. If oil touches the exhaust pipe, it may cause

a bad smell, smoke, and/or a fire.

If you check the oil level just after stopping the engine, wait a few minutes for the oil to drain back into the oil pan before checking the level. Just after driving or while the engine is warm, the engine oil level reading may be in a range between the upper level and the notch mark. This is caused by thermal expansion of the engine oil. To prevent overfilling the engine oil, do not add any additional oil above the upper level when the engine is cold.

! Changing the oil and oil filter

Change the oil and oil filter according to the maintenance schedule in the “Warranty and Maintenance Booklet”. The engine oil and oil filter must be changed more frequently than listed in the maintenance schedule when driving on dusty roads, when short trips are frequently made, or when driving in extremely cold whether.

1. Warm up the engine by letting the engine idle for about 10 minutes to ease draining the engine oil.

2. Park the vehicle on a level surface and stop the engine.

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3. Remove the oil filler cap.

2.5-liter turbo models

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Maintenance and service

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2.0-liter turbo models

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Maintenance and service

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Non-turbo models

4. Drain out the engine oil by removing the drain plug while the engine is still warm. The used oil should be drained into an appropriate container and disposed of properly.

Be careful not to burn yourself with hot engine oil.

5. Wipe the seating surface of the drain plug with a clean cloth and tighten it securely with a new sealing

washer after the oil has completely drained out.

6. Remove under cover (For turbo).

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Turbo models

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Non-turbo models

7. Remove the oil filter with an oil filter wrench.

8. Before installing a new oil filter, apply a thin coat of engine oil to the seal.

9. Clean the rubber seal seating area of the lower crank case/oil cooler (For Turbo) and install the oil filter by hand turning. Be careful not to twist or damage the seal.

10.Tighten it approximately two-thirds of a turn after the seal makes contact with the lower crank case/oil cooler (For Turbo).

Maintenance and service

Never over tighten the oil filter because that can result in an oil leak.

11.Reinstall under cover (For Turbo).

12.Pour engine oil through the filler neck.

Oil capacity (guideline):

Non-turbo models:

4.2 US qt (4.0 liters, 3.5 Imp qt)

Turbo models:

4.8 US qt (4.5 liters, 4.0 Imp qt)

The oil quantity indicated above is only guideline. The necessary quantity of oil depends on the quantity of oil that has been drained. The quantity of drained oil differs slightly depending on the temperature of the oil and the time the oil is left flowing out. After refilling the engine with oil, therefore, you must the dipstick to confirm that the level is correct.

13.Start the engine and make sure that no oil leaks appear around the filter’s rubber seal and drain plug.

14.Run the engine until it reaches the normal operating temperature. Then stop the engine and wait a few minutes to allow the oil drain back. Check the oil level

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Maintenance and service

again and if necessary, add more engine oil.

Be careful not to spill engine oil when adding it. If oil touches the exhaust pipe, it may cause a bad smell, smoke, and/or a fire.

! Recommended grade and viscosity

Oil grade:

ILSAC GF-3, which can be identified with the new API certification mark (Starburst mark) or API classification SL with the words “ENERGY CONSERVING” (if you cannot obtain the oil with SL grade, you may use SJ grade “ENERGY CONSERVING” oil).

These recommended oil grades can be identified by looking for either or both of the following marks displayed on the oil container.

API Service label

1) Indicates the oil quality by API designations

2) Indicates the SAE oil viscosity grade

3) Indicates that the oil has fuel saving capabilities

SAE

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Maintenance and service

-30 -20 -10 0 10 20 30 40

06020 80 10040

-20

5W-30*

New API Certification Mark (Starburst Mark)

In choosing an oil, you want the proper quality and viscosity, as well as one that will add to fuel economy. The following table lists the recommended viscosities and applicable temperatures. When adding oil, different brands may be used together as long as they are the same API classification and SAE viscosity as those recommended by SUBARU.

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10W-30, 10W-40

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SAE viscosity number and applicable temperature

*: 5W-30 is preferred.

Engine oil viscosity (thickness) affects fuel economy. Oils of lower viscosity provide better fuel economy. However, in hot weather, oil of higher viscosity is required to properly lubricate the engine.

Use only engine oil with the recommended grade and viscosity.

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Maintenance and service

! Recommended grade and viscosity

under severe driving conditions

If the vehicle is used in desert areas, in areas with very high temperatures, or used for heavy-duty applications such as towing a trailer, use of oil with the following grade and viscosities is recommended.

API classification SL (or SJ):

SAE viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50

! Synthetic oil

You can use synthetic engine oil that meets the same requirements given for conventional engine oil. When using synthetic oil, you must use oil of the same classification, viscosity and grade shown in this owner’s manual, and must follow the oil and filter changing intervals shown in the maintenance schedule.

Cooling system

Never attempt to remove the radiator cap until the engine has been shut off and has cooled down completely. Since the coolant is under pressure, you may suffer serious burns from a spray of boiling hot coolant when the cap is removed.

" The cooling system has been filled at the factory with a high quality, corrosion-inhibiting, year-around coolant which provides protection against freezing down to –33°F (–36°C). For adding, use genuine SUBARU coolant or an equivalent: a mixture of 50% soft water and 50% ethylene-glycol basis coolant. Use of improper coolants may result in corrosion in the cooling system. It is important to maintain protection against freezing and corrosion, even if freezing temperatures are not expected. Never mix different kinds of coolant. " Do not splash the engine coolant over paint-

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Maintenance and service

ed parts. The alcohol contained in the engine coolant may damage the paint surface.

! Cooling fan, hose and connections

Your vehicle employs an electric cooling fan which is thermostatically controlled to operate when the engine coolant reaches a specific temperature. If the radiator cooling fan does not operate even when the engine coolant temperature gauge exceeds the normal operating range, the cooling fan circuit may be defective. Check the fuse and replace it if necessary. If the fuse is not blown, have the cooling system checked by your SUBARU dealer.

If frequent addition of coolant is necessary, there may be a leak in the engine cooling system. It is recommended that the cooling system and connections be checked for leaks, damage, or looseness.

! Engine coolant

! Checking the coolant level

FULL

LOW

1) “FULL” level mark

2) “LOW” level mark

Check the coolant level at each fuel stop.

1. Check the coolant level on the outside of the reservoir while the engine is cool.

2. If the level is close to or lower than the “LOW” level mark, add coolant up to the “FULL” level mark. If the reserve tank is empty, remove the radiator cap and refill as required.

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Maintenance and service

coolant may damage the paint surface.

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1) Rubber gaskets

3. After refilling the reserve tank and the radiator, reinstall the caps and check that the rubber gaskets inside the radiator cap are in the proper position.

" Be careful not to spill engine coolant when adding it. If coolant touches the exhaust pipe, it may cause a bad smell, smoke, and/or a fire. " Do not splash the engine coolant over painted parts. The alcohol contained in the engine

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! Changing the coolant

1) Drain plug

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Change the engine coolant using the following procedures according to the maintenance schedule.

1. Remove the under cover.

2. Place a proper container under the drain plug and loosen the drain plug.

3. Loosen the radiator cap to drain the coolant from the radiator. Then drain the coolant from the reserve tank. Tighten the drain plug securely.

4. Install the under cover.

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Non-turbo models

1) Filler neck

2) Fill up to this level

Maintenance and service

Turbo models

1) Filler neck

2) Fill up to this level

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5. Slowly pour the coolant and fill to the radiator filler neck. Do not pour the coolant too quickly, as this may lead to insufficient air bleeding and trapped air in the system.

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Maintenance and service

Guideline of coolant quantity (including coolant in reservoir tank):

Non-turbo models:

MT. 7.4 US qt (7.0 liters, 6.2 Imp qt) AT. 7.3 US qt (6.9 liters, 6.1 Imp qt)

Turbo models:

MT. 8.1 US qt (7.7 liters, 6.8 Imp qt) AT. 8.0 US qt (7.6 liters, 6.7 Imp qt)

6. Pour the coolant and fill to the reservoir tank’s “FULL” level mark.

1) “FULL” level mark

2) “LOW” level mark

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FULL

LOW

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1) Rubber gaskets

Maintenance and service

7. Put the radiator cap back on and tighten firmly. At this time, make sure that the rubber gasket in the radiator cap is correctly in place.

8. Start and run the engine for more than five minutes at 2,000 to 3,000 rpm.

9. Stop the engine and wait until the coolant cools down (122 to 140°F [50 to 60°C]). If there is any loss of coolant, add coolant to the radiator’s filler neck and to the reserve tank’s “FULL” level.

10.Put the radiator cap and reservoir cap back on and tighten firmly.

Air cleaner element

The air cleaner element functions as a filter screen. When the element is perforated or removed, engine wear will be excessive and engine life shortened.

The air cleaner element is a viscous type. It is unnecessary to clean or wash the element.

Do not operate the engine with the air cleaner element removed. The air cleaner element not only filters intake air but also stops flames if the engine backfires. If the air cleaner element is not installed when the engine backfires, you could be burned.

! Replacing the air cleaner element

! Non-turbo models

Replace the air cleaner element according to the maintenance schedule in the “Warranty and Maintenance Booklet”. Under extremely dusty conditions, replace it more frequently. It is recommended that you always use genuine SUBARU parts.

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Maintenance and service

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1) Bolt

1. Remove the bolt securing the rear air cleaner element case.

2. Unsnap the three clamps holding the rear air cleaner element case.

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1) Air cleaner element

3. Separate the rear air cleaner element case from the front cleaner element case and remove the air cleaner element.

4. Clean the inside of the front and rear air cleaner element cases with a damp cloth and install a new air cleaner element.

5. Insert the four projections on the rear air cleaner element case into the slits on the front air cleaner element case and snap the three clamps on the rear air cleaner element case and then tighten the bolt.

Maintenance and service

! Turbo models

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1. Unsnap the two clamps holding the air cleaner case cover.

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1) Air cleaner case cover

2) Air cleaner element

2. Open the air cleaner case cover and remove the air cleaner element.

3. Clean the inside of the air cleaner cover and case with a damp cloth and install a new air cleaner element.

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Maintenance and service

Spark plugs

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4. To install the air cleaner case cover, insert the two projections on the air cleaner case cover into the slits on the air cleaner case and then snap the two clamps on the air cleaner case cover.

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It may be difficult to replace the spark plugs. It is recommended that you have the spark plugs replaced by your SUBARU dealer.

The spark plugs should be replaced according to the maintenance schedule in the “Warranty and Maintenance Booklet”.

" When disconnecting the spark plug cables, always grasp the spark plug cap, not the ca-

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