Exhaust Manifold Cleaning and Inspection

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

WARNING: Wear safety glasses in order to avoid eye damage.

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: Inspecting Exhaust Manifolds
  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 Alignment Or Surface Flatness Of Exhaust Manifold Flanges
Courtesy of GENERAL MOTORS CORP.