Engine: Description and Operation

The 4.0 Liter (242 CID) six-cylinder engine is an In-line, lightweight, overhead valve engine.
This engine is designed for unleaded fuel. The engine cylinder head has dual quench-type combustion chambers that create turbulence and fast burn ing of the air/fuel mixture. This results in good fuel economy.

Fig.1 Engine Firing Order:

The cylinders are numbered 1 through 6 from front to rear. The firing order is 1 - 5 - 3 - 6 - 2 - 4 .
The crankshaft rotation is clockwise, when viewed from the front of the engine. The crankshaft rotates within seven main bearings. The camshaft rotates within four bearings.

Fig.2 Build Date Code Location:

Build Date Code
The engine Build Date Code is located on a machined surface on the right side of the cylinder block between the No.2 and No.3 cylinders .
The digits of the code identify:
- 1st Digit - The year (8 = 1998).
- 2nd & 3rd Digits - The month (01 - 12).
- 4th & 5th Digits - The engine type/fuel system compression ratio (MX = A 4.0 Liter (242 CID) 8.7:1 compression ratio engine with a multi-point fue] injection system).
- 6th & 7th Digits - The day of engine build (01 - 31).
1. FOR EXAMPLE: Code * 801MX12 * identifies a 4.0 Liter (242 CID) engine with a multi-point fue] injection system, 8.7:1 compression ratio and built on January 12, 1998.