Engine

Engine
The 3.5L (4V) is a V-6 engine with the following features:
^ Dual overhead camshafts
^ Four valves per cylinder
^ Sequential multi-port fuel injection (SFI)
^ An aluminum lower intake manifold and a composite upper intake manifold
^ Aluminum cylinder heads
^ An aluminum, 60-degree V-cylinder block
^ Timing chain driven coolant pump
^ Variable camshaft timing (VCT) system
^ The 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 is covered in Computers and Control Systems.

Induction System
The sequential multi-port fuel injection (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 valve train uses direct acting mechanical buckets (DAMB). The camshaft lobes are positioned directly above mechanical buckets which are positioned on top of the valves.

Variable Camshaft Timing (VCT) system
The VCT system changes intake camshaft timing dependent on engine speed, load and oil temperature. Oil pressure advances and retards camshaft timing to improve low and high speed engine performance, engine idle quality and exhaust emissions.

Positive Crankcase Ventilation (PCV) 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, timing chain tensioners, and VCT solenoids. 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:
^ Radiator
^ Timing chain driven coolant pump
^ Dual electric fan assemblies
^ Degas bottle (aids in maintaining the correct volume of engine coolant)
^ Coolant thermostat
^ Coolant hoses