Engine

Engine
The 3.0L (4V) is a V-6 engine with the following features:
^ Dual overhead camshafts
^ Four valves per cylinder
^ Sequential multi-port fuel injection (SFI)
^ A composite lower intake manifold and a composite upper intake manifold
^ Aluminum cylinder heads
^ Two-piece design aluminum cylinder block
^ Electronic ignition system with 6 ignition coils

Identification
For quick identification refer to the safety certification decal.
^ The decal is located on the LH front door lock face panel.
^ An engine identification label is also attached to the engine.
^ The symbol code on the identification tag identifies each engine for determining parts usage; for instance, engine displacement in liters or cubic inch displacement and model year.

Exhaust Emission Control System
Operation and required maintenance of the exhaust emission control devices used on this engine are covered in Computers and Control Systems.

Induction System
The SFI provides the fuel/air mixture needed for combustion in the cylinders. The 6 solenoid-operated fuel injectors:
^ are mounted between the fuel rail and the 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.

Valve Train
The camshafts are mounted in the cylinder heads and act against a roller follower to open and close the valves. A hydraulic lash adjuster is located on one side of the roller follower and the valve tip on the opposite end. The camshafts are driven off the front of each cylinder head by 2 chains (one each side). Both of the chains are driven by sprockets that are located on the crankshaft, just in front of the oil pump.

Positive Crankcase Ventilation System
All engines are equipped with a closed-type positive crankcase ventilation system recycling the crankcase vapors to the upper intake manifold.

Lubrication System
The engine lubrication system is of the force-feed type in which oil is supplied under full pressure to the crankshaft, connecting rod bearings and timing chain tensioners. The flow of oil to the valve tappets and valve train is controlled by a restricting orifice located in the head gaskets.

Oil Pump
The lubrication system 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.

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 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.
^ Oil pump displacement has been selected to provide adequate volume to make sure of correct oil pressure both at hot idle and maximum speed.
^ 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.

Cooling System
The engine cooling system includes the following components:
^ Radiator
^ Electric cooling fan motor
^ Degas bottle (aids in maintaining the correct volume of engine coolant)
^ Coolant thermostat
^ Coolant hoses

Engine Cylinder Identification

Engine Cylinder Identification: