Engine: Description and Operation

The compact Ford 60° 4.0L V-6 engine:
- is of lightweight, cast iron construction.
- has a precision-molded cast iron crankshaft.
- has replaceable aluminum/tin alloy crankshaft main bearing.
- has replaceable copper alloy camshaft bearing and connecting rod bearing.
- has forged-steel connecting rods.
- uses a distributorless ignition system.

Engine Identification
For quick identification, refer to the vehicle control information decal mounted under the hood:
- The decal lists correct information needed for servicing.
An engine identification label is attached to the engine:
- It identifies each engine for determining parts usage.
- It identifies the engine displacement.
- It identifies the model year.

Emission Calibration Label

Note: It is critical that the engine codes and the calibration number are known when ordering parts or making inquiries.

The emission calibration label is located on the radiator support:
- It identifies the engine calibration number.
- It identifies the engine code number and the revision level.

Induction System
1. The air/fuel mixture needed by the engine is provided by the sequential electronic fuel injection system.
2. Fuel:
- is supplied from the fuel tank by a fuel pump.
- is filtered into the fuel injection supply manifold.
- is delivered by the fuel injectors. A fuel damper is in place to prevent fluctuations in pressure caused by injector pulsation.

Crankshaft
1. The crankshaft:
- is located at the bottom of the engine.
- is supported on four steel-backed, aluminum crankshaft main bearings.
2. To provide smooth engine operation, the piston crankpins are positioned to provide a power impulse every 120° of crankshaft rotation. This spacing provides quiet smooth operation.
3. The crankshaft is connected to the camshaft by two sprockets and a timing chain, providing a 2:1 drive ratio.

Camshaft
The camshaft:
- is supported by four camshaft bearings.
- thrust loads and end play are limited by the camshaft thrust plate.
- has a synchronizer drive gear located at the rear of the camshaft and part of the casting.
The camshaft synchronizer:
- drives the oil pump through the oil pump intermediate shaft.
- has a Camshaft Position (CMP) Sensor is mounted on top of the camshaft synchronizer.

Valve Train
The roller valve tappets:
- provide automatic lash adjustment.
- ride on the camshaft.
- transfer up-and-down motion to the rocker arms through the push rods then the motion is delivered to the exhaust valves and the intake valves.

Positive Crankcase Ventilation System
The engine is equipped with a positive closed type ventilation system recycling the crankcase vapors to the upper intake manifold.

Engine Cooling System
The 4.0L engine is liquid cooled by:
- a centrifugal water pump driven by the crankshaft.
- a radiator.
- a water thermostat which prevents coolant flow to the radiator until the engine is at normal operating temperature.

Drive Belt System
Vehicles equipped with the 4.0L engine use a poly-v design drive belt with a self-adjusting drive belt tensioner.