Ford Cobra 4.6L 4V User Manual

303-01C-1 303-01C-1Engine — Cobra 4.6L (4V)

DESCRIPTION AND OPERATION

Engine

WARNING: Do not operate the engine
with the hood open until the fan blade has been
first examined for possible cracks and separation.

The 4.6L (4V) (281 CID) Cobra engine is a V-8
with the following features:

• intercooled supercharger

• dual overhead camshafts

• four valves per cylinder

• sequential multiport fuel injection (SFI)

• an aluminum intake manifold

• aluminum cylinder heads

• a cast aluminum, 90-degree V- cylinder block

• individually chain-driven camshafts with a

hydraulic timing chain tensioner on each timing
chain

• the electronic ignition system with eight ignition

coils

Induction System

The sequential multiport fuel injection (SFI)
provides the fuel/air mixture needed for combustion
in the cylinders. The eight solenoid-operated fuel
injectors:

• are mounted in the lower intake manifold.

• meter fuel into the air intake stream in accordance

with engine demand.

• are positioned so that their tips direct fuel just

ahead of the engine intake valves.

• are connected in series with the fuel pressure

sensor.

• supply fuel from the fuel tank with a fuel pump

mounted in the fuel tank.

A constant fuel pressure drop is maintained across
the fuel injectors by the fuel pressure sensor. The
fuel pressure sensor:

• is positioned upstream from the fuel injectors on

the fuel injection supply manifold.

Identification

Always refer to these labels when replacement parts
are necessary or when checking engine calibrations.
The engine parts often differ within a CID family.

Valve Train

The valve train operates as follows:

• ball-tip hydraulic lash adjusters provide automatic

lash adjustment.

Verification of the identification codes will ensure
that the correct parts are obtained. These codes
contain all the pertinent information relating to the
dates, optional equipment and revisions. The Ford
Master Parts Catalog contains a complete listing of

• roller followers ride on the camshaft lobes,

transferring the up-and-down motion of the
camshafts to the valves in the cylinder heads.

Positive Crankcase Ventilation System

the codes and their application.

All engines are equipped with a closed-type positive

Code Information crankcase ventilation system recycling the crankcase
The engine code information label, located on the

side of the valve cover and the front side of the

vapors to the upper intake manifold.

Lubrication System

valve cover, contains the following:

The engine lubrication system operates as follows:

• engine build date

• oil is drawn into the oil pump through the oil

• engine plant code

• engine code

Exhaust Emission Control System

pump screen cover and tube in the sump of the
oil pan.

• oil is pumped through the oil bypass filter on the

left front side of the cylinder block.

Operation and necessary maintenance of the exhaust
emission control devices used on this engine is
covered in the Powertrain Control/Emissions

Diagnosis (PC/ED) manual.

• oil enters the main oil gallery where it is

distributed to the crankshaft main journals and to
both cylinder heads.

Copyright  2002, Ford Motor Company

Last updated: 6/14/2002

2003 Mustang, 8/2002

303-01C-2 303-01C-2Engine — Cobra 4.6L (4V)

DESCRIPTION AND OPERATION (Continued)

• From the main journals, the oil is routed through • Oil pump displacement has been selected to

cross-drilled passages in the crankshaft to provide adequate volume to ensure correct oil
lubricate the connecting rod bearings. Controlled pressure both at hot idle and maximum speed.
leakage through the crankshaft main bearings and
connecting rod bearings is slung radially outward
to cool and lubricate the cylinder walls as well as
the entire connecting rod, piston and piston rings
assembly.

• The left cylinder head is fed from a drilling into

the supply passage feeding the main gallery at the
front of the cylinder block. The right cylinder Cooling System
head is fed from a drilling into the rear of the
main gallery. Main gallery pressure is reduced as
it enters the cylinder head galleries through fixed
serviceable orifices located at the upper part of
the feed passages. It is this reduced pressure in
the cylinder head galleries which feeds the
camshaft journals, the hydraulic lash adjusters
and the primary and secondary timing chain
tensioners.

• The camshaft lobe and roller followers are

lubricated by splash created through valve train
operation.

Oil Pump • heater water hoses
The lubrication system of the 4.6L (4V) engine is

designed to provide optimum oil flow to critical
components of the engine through its entire
operating range. The heart of the system is a
positive displacement internal gear oil pump using
top seal rotors. Generically this design is known as
a gerotor pump, which operates as follows.

• The oil pump is mounted on the front face of the

cylinder block. • The serpentine drive belt is routed over each

• The inner rotor is piloted on the crankshaft post

and is driven through flats on the crankshaft.

• System pressure is limited by an integral,

internally-vented relief valve which directs the
bypassed oil back to the inlet side of the oil
pump.

• The relief valve calibration protects the system

from excessive pressure during high viscosity
conditions.

• The relief valve is designed to provide adequate

connecting rod bearing lubrication under
high-temperature and high-speed conditions.

The engine cooling system includes the following:

• radiator

• water pump

• the electric cooling fan motor and fan blade,

activated by the variable control module

• the degas bottle, which aids in maintaining the

correct volume of engine coolant

• water thermostat

• upper radiator hose

• lower radiator hose

Drive Belt System

The 4.6L (4V) DOHC engine is equipped with a
serpentine drive belt. To ensure maximum life, a
replacement drive belt should be of the same type
as originally installed.

• The accessories mounted on the front of the

engine are belt-driven by the crankshaft.

accessory pulley, driven by the crankshaft pulley
bolted to the crankshaft.

For service procedures, including tensioning, refer to
Section 303-05.

2003 Mustang, 8/2002

303-01C-3 303-01C-3Engine — Cobra 4.6L (4V)

DESCRIPTION AND OPERATION (Continued)

Item Part Number Description Item Part Number Description

1 6F066 Supercharger assembly
2 N806154 Screws (2 req’d)
3 9F715 Idle air control valve
4 — Idle air control valve gasket
5 9P697 Spacer assembly
6 9E936 Throttle body gasket
7 9E926 Throttle body
8 — Bolts (4 req’d)

9 — Bolts (2 req’d)
10 9E926 Throttle position sensor
11 N804178 Nuts (4 req’d)
12 — Studs (4 req’d)

(Continued)

13 — Spacer assembly gasket
14 9D475 Exhaust gas recirculation

valve
15 — Stud
16 9D477 Exhaust gas recirculation tube
17 — Manifold absolute pressure

sensor
18 9J460 Differential pressure feedback

EGR system
19 9J459 Exhaust gas recirculation

vacuum regulator
20 9J472 Vacuum accessory bracket

2003 Mustang, 8/2002

303-01C-4 303-01C-4Engine — Cobra 4.6L (4V)

DESCRIPTION AND OPERATION (Continued)

2003 Mustang, 8/2002

303-01C-5 303-01C-5Engine — Cobra 4.6L (4V)

DESCRIPTION AND OPERATION (Continued)

Item Part Number Description Item Part Number Description

1 12B637 Wiring harness
2 9C986 Fuel pulse damper
3 9F792 Fuel injection supply

manifold
4 9F593 Fuel injector
5 — Stud
6 9D475 Exhaust gas recirculation

valve
7 W701232 Bolt
8 N806979 Stud
9 — EGR vacuum hoses

10 6F089 Vacuum actuator valve
11 N605892 Bolts (2 req’d)
12 — Bolts (10 req’d)

(Continued)

13 9J447 Lower intake manifold
14 9L438 Coolant intake manifold

gasket
15 — Coolant tubes
16 9N491 Coolant intake manifold
17 W701592 Bolt
18 NL443 Inter cooler hose
19 NL443 Inter cooler hose
20 W506404 Bolts (10 req’d)
21 6K755 Charge air cooler
22 6F066 Supercharger assembly
23 N605892 Bolt
24 9726 Accelerator cable bracket

2003 Mustang, 8/2002