Subject: | LL8 Cylinder Head -- Information on Service Replacement Cylinder Head Changes that Apply to 2006 and 2007 Model Years |
Models: | 2006-2007 Buick Rainier |
2006-2007 Chevrolet TrailBlazer Models |
2006-2007 GMC Envoy Models |
2006-2007 Saab 9-7X |
with Vortec™ 4.2L I-6 Engine (VIN S -- RPO LL8) |
For 2006-2007, Inline 6 engines requiring a cylinder head replacement with P/N 89017826, technicians will notice that the left threaded bolt hole for the timing chain stationary guide upper mounting hole has been enlarged to 8 mm (0.31 in) and the fourth fuel rail mounting hole has been eliminated.
To install this replacement head on 2006 and 2007 vehicles, you must first remove the left timing chain stationary guide from the engine and enlarge the upper mounting hole on the guide to accept a new 8 mm bolt. You must also adjust the fourth injector fuel rail bracket tab for clearance.
Important: Refer to SI for all Disassembly and Assembly service procedures.
Notice: Do not drill the guide while installed on the engine, metal fallout from drilling operation may cause consequential engine damage.
Tighten
Tighten the timing chain guide to 10 N·m (89 lb in).
Notice: Do not pry on the fuel injectors or the fuel injector rail when adjusting the bracket. Refer to callout #1 in the fuel rail illustration as a rotating point to adjust the bracket using two pairs of pliers.
Part Number | Description | Qty |
---|---|---|
11588725 | Bolt, M8 X 1.25 X 35 | 1 |
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
---|---|---|
J0785 | Guides, Timing Chain - Replace | Use Published Labor Operation Time |
For vehicles repaired under warranty, use:
Labor Operation | Description | Failed Object | Fault/Reason | Location Code | Warranty Type | Repair/Action Code | Labor Time |
---|---|---|---|---|---|---|---|
2152402 | Guides, Timing Chain - Replace | 21524 | 00 | 0 | 01 | 01 | Use Published Labor Operation Time |