Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. 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:
- 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

Fig 1: Exhaust Manifold Inspection Areas

Courtesy of GENERAL MOTORS CORP.

Measure the alignment or surface flatness of the exhaust manifold flanges using a straight edge and a feeler gage. Refer to Engine Mechanical Specifications .
If the surface flatness is not within the specifications, the exhaust manifold is warped and must be replaced.

Fig 2: Measuring Exhaust Manifold Flanges Alignment

Courtesy of GENERAL MOTORS CORP.