Isuzu Engine >> REVISED CYLINDER HEAD REMOVAL & INSTALLATION PROCEDURE

Isuzu Engine >> REVISED CYLINDER HEAD REMOVAL & INSTALLATION PROCEDURE

Revised Cylinder Head Removal & Installation Procedure For
2001-2003 GM 6.6L VIN 1 Diesel Engines

The AERA Technical Committee offers the following information on a revised cylinder head installation procedure for 2001-2003 GM 6.6L VIN 1 diesel engines. These modern diesel engines are referred to as the Duramax diesel and are a result of a joint venture between GM and Isuzu. This procedure should be used any time the cylinder head is being removed and re-installed. This supersedes information found in earlier published service manuals.
Figure 1. Head Bolt Removal Sequence

It is now recommended that all M12 cylinder head bolts should be replaced at the time of cylinder head installation. These bolts have a pre-applied molybdenum disulfide coating for thread lubrication. Do not remove the coating or use any additional lubricant. Improperly lubricated threads will adversely affect the bolt torque and clamp load. Improper bolt torque and clamp load can lead to engine damage.

Notice: The left and right cylinder head gaskets are not interchangeable. Improper placement of the cylinder head gasket will block coolant and oil passages. Blocked coolant and oil passages will cause severe engine damage. Three different grade (thickness) head gaskets are available and use is determined by piston projection (See Figure 1). Those gaskets are also marked by no hole, one hole or two holes to indicate the different grades as well as ?L" and ?R" for left and right banks respectfully.

Cylinder Head Gasket Selection

Right Side Left Side Piston Protrusion Holes
Grade A 97288223 97309562 .0088 to less than .0108 none
Grade B 97288224 97309563 .0108 to less than .0128 one
Grade C 97309561 97288228 .0128 to less than .0148 two

After selecting the proper gasket determined by the cylinder with the highest piston protrusion follow the steps listed below to tighten the new cylinder head bolts.

1. Tighten new 12 mm bolts in sequence to 37 ft/lbs (50 Nm).
2. Tighten new 12 mm bolts in sequence to 59 ft/lbs (80 Nm).
3. Rotate those bolts in sequence an additional 90° turn using a torque angle meter.
4. Rotate those bolts in sequence an additional 75° turn using a torque angle meter.
5. Tighten the M8 cylinder heat bolts to 18 lb ft (25 Nm).

AERA is unaware of an aftermarket supplier for these gaskets or bolts.

The AERA Technical Committee

---

Looking for replacement Isuzu engines? Visit our online Rebuilt Engines Store. Need to fix your Isuzu engine? Access here the comprehensive online repair guide for your Isuzu engine. Click Here to find a used Isuzu engine.