Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different variant/trim than selected.

Fig 1: View Of Exhaust Manifold, Heat Shield & Mounting Bolts

Courtesy of GENERAL MOTORS CORP.

CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.

Dry the exhaust manifold with compressed air.
Inspect the exhaust manifold for the following conditions:
- Exhaust manifold-to-cylinder head gasket surface for excessive scratches or gouging.
- Take down studs for damaged threads
- Loose or damaged heat shield (603) or missing bolts (604)

Fig 2: Measuring Exhaust Manifold To Cylinder Head Surface For Warpage

Courtesy of GENERAL MOTORS CORP.

Use a straight edge and a feeler gage to measure the exhaust manifold cylinder head deck for warpage.
An exhaust manifold deck with warpage in excess of 0.25 mm (0.010 in), may cause an exhaust leak and may effect OBD II system performance.

Exhaust manifolds not within specifications must be replaced.