Inspection Procedure

WARNING: This page is about a different car, the 2005 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Inspecting Left Exhaust Manifold For Corrosion & Bolt Hole Damage

Courtesy of GENERAL MOTORS CORP.

Inspect the left exhaust manifold for the following:
- Damage or excessive corrosion to the exhaust manifold exterior (1)
- Damage to the exhaust manifold mounting holes (2)
- Damage to the threaded holes (3) for the heat shield
- Damage to the exhaust manifold flange bolt holes (4)

Fig 2: Inspecting Left Exhaust Manifold For Damage To Exhaust Passages & Gasket Sealing Surfaces

Courtesy of GENERAL MOTORS CORP.

Inspect the left exhaust manifold for the following:
- Damage to the gasket sealing surfaces (1)
- Damage or restrictions within the exhaust passages (2)
Repair or replace the left exhaust manifold and/or components as necessary.

Fig 3: Measuring Alignment Of Left Exhaust Manifold Flanges

Courtesy of GENERAL MOTORS CORP.

Measure the alignment or surface flatness of the exhaust manifold flanges, using a straight edge and a feeler gage. Exhaust manifold surface flatness must not exceed 0.254 mm (0.010 in).
If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.