Exhaust Manifold - Cracks on RH Side of Engine
File In Section: 6 - EngineBulletin No.: 67-61-19
Date: October, 1996
Subject:
RH (Right Hand) Side Exhaust Manifold Cracks
(Install a New Manifold)
Models:
1994-96 Chevrolet Caprice with 4.3L, 5.7L Engines
(VINs W, P - RPOs L99, LT1) and 4L60-E Transmission
Condition
Some vehicles, primarily police vehicles, may exhibit a cracked exhaust manifold on the RH side of the engine.
Cause
Thermal cycling stress due to high ambient temperatures caused by extreme driving conditions and high engine speeds.
Correction
There are two types of exhaust manifolds used for the 1994 through 1996 model years. One manifold for the 1994 and early 1995 model years has the AIR tube screwed directly into the manifold. The other type of manifold for the late 1995 and all 1996 model years uses a male fitting in the exhaust manifold which the AIR tube attaches to.
Parts Information
To address the exhaust manifold cracking concern for the 1994 and early 1995 vehicles install manifold, P/N 12524289, and cut the metal tie bar between the number 6 and 8 exhaust port. See Figure 1. For the late 1995 and all 1996 vehicles install exhaust manifold, P/N 12556731. These manifolds are new for 1996 and are cast without the metal tie bar. Use gasket, P/N 12552469, and refer to Bulletin 47-66-03 for bolt usage.
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Labor Time
J0100 Use published labor operation time.