GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Impala 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L 🢒 Exhaust Manifold Cleaning and Inspection

    Object Number: 1411884 Size: SH

    Note: Do not use the exhaust manifold-to-cylinder head gaskets again. 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.

  1. Clean the exhaust manifold (600) and heat shield (603) in solvent.

    2. Warning: Refer to Safety Glasses Warning in the Preface section.

  2. Dry the exhaust manifold with compressed air.
  3. Inspect the exhaust manifold-to-cylinder head gasket surface for excessive scratches or gouging.
  4. Inspect for a loose, damaged, or cracked heat shield (603).
  5. Inspect the studs (605) for damaged threads.

    6. Object Number: 66607 Size: SH
  6. Use a straight edge and a feeler gage and measure the exhaust manifold cylinder head deck for warpage.

    7. An exhaust manifold deck with warpage in excess of 0.25 mm (0.01 in) within the 2 front or 2 rear runners or 0.5 mm (0.02 in) overall, may cause an exhaust leak and may affect OBD II system performance. Exhaust manifolds not within specifications must be replaced.