Engine: Description and Operation

DESCRIPTION
The 3.0L engine is an 60° 6 cylinder "V" gasoline engine. It dual overhead camshafts (DOHC). 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). A unique intake air system utilizes a secondary intake port along with a primary intake port. The secondary port is opened and closed by an electronically operated intake manifold runner control (IMRC) deactivation motor, thus improving low and mid-range torque and fuel efficiency.

CYLINDER HEAD
The cylinder heads are aluminum with four valves per cylinder. It requires a special corrosion inhibiting coolant to avoid cooling system damage. Refer to Cooling System for the coolant specifications.

CYLINDER BLOCK
The cylinder block has a cast aluminum upper cylinder block and a cast aluminum lower cylinder block with four integral lower main bearing caps.

INTAKE MANIFOLD
The intake manifold has two parts. An aluminum upper and lower intake manifold with integral intake manifold runner controls (IMRC).

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.
Engine parts often differ within a CID family. Verification of identification codes will make sure that the proper parts are obtained.

TRANSMISSION
Available with an automatic transaxle only.