Engine: Description and Operation

DESCRIPTION
The 3.0L engine is an 6 cylinder "V" gasoline engine. It is of the overhead valve design (cam-in-block). The engine operates on unleaded fuel.

AIR/FUEL SYSTEM
The fuel/air mixture needed for burning in the cylinders is provided by sequential multiport fuel injection (SFI). This fuel induction system is mounted on an aluminum intake manifold which in turn is bolted to cast iron cylinder heads. Refer to Powertrain Management for information on the SFI system and air induction components.

CYLINDER HEAD
The cylinder heads are cast iron with a central plug, dual squish combustion chamber.

CYLINDER BLOCK
The cylinder block is cast iron.


INTAKE MANIFOLD
An aluminum intake manifold is bolted to cast iron cylinder heads.

OIL PUMP
The rotary spur-type oil pump, which develops the oil pressure, is bolted to the No. 4 crankshaft main bearing cap. The spur-driven gear is rotated by the camshaft position sensor housing shaft through an oil pump intermediate shaft.

POSITIVE CRANKCASE VENTILATION (PCV)
This engine incorporates a closed-type positive crankcase ventilation (PCV) system and exhaust emission control system. All engine/emission control systems are covered in Powertrain Management. To maintain the required exhaust emission levels, the fuel system, ignition system, and engine must be kept in good operating condition and meet recommended adjustment specifications.

SERVICING
When performing tests, adjustments or service to the engine, ignition system or fuel system, it is essential to follow the proper procedures and specifications. Refer to the proper component or system. Refer to Powertrain Management for emission control or computer control information. Make sure that the following engine components are not serviceable before replacing damaged or worn engine components:
- crankshaft.
- cylinder heads
- valve guides
- exhaust valves.
- intake valve.
- camshafts.
- cylinder block.

TRANSMISSION
Available with an automatic transaxle only.

VALVE TRAIN
DESCRIPTION
Hydraulic roller valve tappets, providing automatic lash adjustment, ride on camshaft lobes and transfer up and down motion to the rocker arms through push rods. The rocker arms press down on and open the valves.