Exhaust Manifold cleaning and Inspection

WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.

Clean the exhaust manifolds in cleaning solvent.
Dry the components with compressed air.
Inspect the exhaust manifolds for the following:

Fig 1: Inspecting Exhaust Manifolds
Courtesy of GENERAL MOTORS CORP.
- Damage to the gasket sealing surfaces (1)
- Damage to the threaded holes (2)
- Restrictions within exhaust passages
- Broken or damaged exhaust manifold heat shields (3), if applicable
- Broken or damaged exhaust manifold.
Measure the alignment or surface flatness of the exhaust manifold flanges using a straight edge and a feeler gage. Refer to ENGINE MECHANICAL SPECIFICATIONS .

Fig 2: Measuring Alignment Or Surface Flatness
Courtesy of GENERAL MOTORS CORP.

If the surface flatness is not within the specifications, the exhaust manifold is warped and must be replaced.