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

Cleaning Procedure

    Object Number: 1272799 Size: SH
  1. Remove and discard the intake manifold-to-cylinder head gaskets (514).

    2. Object Number: 1807816 Size: SH
  2. Remove the manifold absolute pressure (MAP) sensor (714). Refer to Intake Manifold Removal.

    3. Object Number: 1411900 Size: SH
  3. Remove the evaporative emission (EVAP) canister purge solenoid valve (730), EVAP tube (729), 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. Warning: Refer to Safety Glasses Warning in the Preface section.

  6. Dry the intake manifold with compressed air.

Inspection Procedure

    Object Number: 1807824 Size: SH
  1. Inspect the manifold for the following conditions:
    2. • Damaged gasket or sealing surfaces (1, 5)
    • Loose threaded inserts or studs (2, 4)
    • Debris or restrictions within the passages of the manifold
    • Damaged or broken hose fittings (3, 6)
    • 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.