Engine: Description and Operation

Engine

The engine incorporates the following features:
^ a closed Positive Crankcase Ventilation (PCV) system.
^ an exhaust emission control system.
^ an evaporative emission control system.

Some engines incorporate a fail-safe cooling system.

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 Service Intervals.

Correct engine identification is required to order parts.

The 4.0L SOHC engine consists of the following:
^ single overhead camshafts
^ Sequential Multiport Fuel Injection (SFI)
^ distributorless ignition system
^ aluminum cylinder heads
^ cast iron, 60-degree V cylinder block
^ balance shaft (4x4 vehicles)
^ jackshaft
^ unique engine timing configuration
For quick identification, refer to the vehicle control information decal mounted under the hood.
An engine identification label is attached to the engine. The label identifies the symbol code for determining parts usage.