Description And Operation: Engine

WARNING: Do not operate the engine with the hood open until the fan blade has been examined for possible cracks and separation. A damaged fan can separate during operation. Failure to follow this instruction may result in serious personal injury.

NOTE: When repairing engines, all parts must be contamination free. If contamination/foreign material is present when repairing an engine, premature engine failure may occur.

NOTE: This article contains information, steps and procedures that may not be specific to every engine.

NOTE: If a component fails to meet the specifications, repair or install a new component as necessary.

NOTE: Refer to the appropriate ENGINE - 4.0L SOHC or ENGINE - 4.6L (3V) .

This article covers general procedures and diagnosis and testing of the engine system, except for exhaust emission control devices, the diagnosis of which are covered in the Introduction - Gasoline Engines article.

The engine incorporates the following features:

a closed PCV system. For service, refer to ENGINE EMISSION CONTROL article.
an exhaust emission control system. For service, refer to ENGINE EMISSION CONTROL article.
an Evaporative Emission (EVAP) control system. For service, refer to EVAPORATIVE EMISSIONS article.

Some engines incorporate a fail-safe cooling system. Refer to the appropriate ENGINE - 4.0L SOHC or ENGINE - 4.6L (3V) .

The engine, fuel system, ignition system, emissions system and exhaust system all affect exhaust emission levels and must be maintained according to the maintenance schedule. Refer to the scheduled Maintenance Guide.

Correct engine identification is required to order parts. Refer to the appropriate ENGINE - 4.0L SOHC or ENGINE - 4.6L (3V) .

For complete vehicle and engine identification codes, refer to IDENTIFICATION CODES article.