Inspection Procedure

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora and 2001 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

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 1: Checking Left Exhaust Manifold (1 Of 2)
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 2: Checking Left Exhaust Manifold (2 Of 2)
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.

Fig 3: Measuring Alignment Of Exhaust Manifold Flanges
Courtesy of GENERAL MOTORS CORP.