Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: View Of Exhaust Manifold

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Do not reuse the exhaust manifold-to-cylinder head gaskets. Upon installation of the exhaust manifold, install a NEW gasket. An improperly installed gasket or leaking exhaust system may affect on-board diagnostics (OBD) II system performance.

Clean the exhaust manifold in solvent.

CAUTION: Refer to Safety Glasses Caution .

Dry the exhaust manifold with compressed air.
Internal heat cracks are allowed. Do not replace the exhaust manifold for this condition.
Inspect the heat shield for damage.

Fig 2: Checking Exhaust Manifold Mounting Face For Warpage

Courtesy of GENERAL MOTORS CORP.

Use a straight edge and a feeler gage and measure the exhaust manifold mounting face for warpage.
An exhaust manifold face with warpage in excess of 0.25 mm (0.0100 in) may cause an exhaust leak and may affect OBD II system performance. Exhaust manifolds not within specifications must be replaced.