Inspection Procedure

WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: View of Exhaust Manifold

Courtesy of GENERAL MOTORS CORP.

Inspect the exhaust manifold for the following:
- Damage to the exhaust crossover sealing area (1)
- Damage or restrictions within the exhaust passages (2)
- Damage to the gasket sealing surfaces (3)

Fig 2: Inspecting Exhaust Manifold

Courtesy of GENERAL MOTORS CORP.

Inspect the exhaust manifold for the following:
- Damage to the exhaust manifold mounting holes (1)
- Damage or broken welds (2)
- Damage or excessive corrosion to the exhaust manifold exterior (3)
- Damage to the oxygen sensor threaded hole (4)
Repair or replace the exhaust manifold and/or components as necessary.

Fig 3: Measuring Surface Flatness of 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.