Intake Manifold Cleaning and Inspection

Important:  Do not reuse the lower intake manifold gaskets or end seals.

1. Clean the intake manifold in an approved solvent.
   • Clean debris out of all bolt holes. Clean the intake manifold gasket sealing surfaces.
   • Clean all carbon from the EGR passages.
   • Clean all intake manifold ports.
   CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.
2. Dry the intake manifold with compressed air.
3. Inspect the following:
   • The intake manifold bolt holes (1) for cracks and/or damage
   • The MAP sensor sealing surface (2) for damage
   • The purge solenoid sealing surface (4) for damage. The purge solenoid bolt has a sealer that may come off during removal of the bolt. Ensure all sealant is removed from the bolt hole.
   • The intake manifold-to-cylinder head sealing surfaces (3) for damage
   • The EGR adapter mounting surface for damage
   • The throttle body studs (5) for damage. Replace as necessary.
   • The throttle body mounting surface (6) for damage
   • The oil fill tube hole (7) for signs of leakage. Reseal as necessary.
   • PCV port (8) for debris or varnish buildup
   • EGR pipe for damage
   Fig 1: Intake Manifold Inspection Areas

   Courtesy of GENERAL MOTORS CORP.