Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Clean the exhaust manifolds in solvent.
CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.
Dry the components with compressed air.
Inspect the exhaust manifolds for the following:
- Damage to the gasket sealing surfaces
- Damaged exhaust gas recirculation (EGR) pipe mounting studs (if applicable)
- Damage to the exhaust manifold studs
- Broken or damaged heat shields
- Cracks in the exhaust manifold
- Restrictions within the exhaust passages
Fig 1: Exhaust Manifold
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 (0.01 in).
If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.

Fig 2: Measuring Exhaust Manifold Flanges Surface Flatness
Courtesy of GENERAL MOTORS CORP.