GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 CTS 🢒 Engine 🢒 Engine Mechanical - 6.0L 🢒 Intake Manifold Cleaning and Inspection

Cleaning Procedure

    Object Number: 1552471 Size: SH
  1. Remove and discard the intake manifold-to-cylinder head gaskets (514).
  2. Remove the manifold absolute pressure (MAP) sensor. Refer to Intake Manifold Removal .
  3. Remove the evaporative emission (EVAP) canister purge solenoid valve, EVAP tubes, and fuel rail with injectors. Refer to Fuel Rail and Injectors Removal .
  4. Remove the throttle body and gasket. Refer to Throttle Body Removal .
  5. Clean the intake manifold in solvent.

    6. Caution: Refer to Safety Glasses Caution in the Preface section.

  6. Dry the intake manifold with compressed air.

Inspection Procedure

    Object Number: 1552558 Size: SH
  1. Inspect the manifold for the following conditions:
    2. • Lose threaded inserts (1)
    • Damaged MAP sensor bore (2)
    • Damaged fuel injector bore (3)
    • Damaged gasket or sealing surfaces (4)
    • Damaged or broken vacuum fittings (5)
    • Debris or restrictions within the passages of the manifold
    • Inspect the composite intake manifold assembly for cracks or other damage.
  2. Inspect the intake manifold cylinder head deck for warpage.
    3. 2.1. Locate a straight edge across the intake manifold cylinder head deck surface.

    Position the straight edge across a minimum of 2 runner port openings.

    2.2. Insert a feeler gage between the intake manifold and the straight edge.

    An intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87 in) area is warped and should be replaced.