51. Intake Manifold Clean and Inspect

CLEANING

Important: Do not reuse the intake manifold-to-cylinder head sealing gaskets.

1. Remove and discard the intake manifold-to-cylinder head gaskets.
2. Remove any remaining gasket and/or gasket material from the following:
^ Throttle body
^ Throttle body adapter heater plate
^ Intake manifold
3. Clean the following intake manifold areas in solvent.
^ Intake manifold gasket grooves
^ Intake manifold passages
^ Brake booster hose passage
^ EVAP solenoid passage
^ PCV vacuum hose passages
^ MAP sensor passage
^ Throttle body adapter heater plate Caution: Wear safety glasses in order to avoid eye damage.
4. Dry the intake manifold and throttle body adapter heater plate with compressed air.

INSPECTION
1. Inspect the following:
^ The sealing grommet on the MAP sensor for tears or damage
^ The fuel rail mounting tabs for damage
^ The intake manifold vacuum passages for debris or restrictions
^ The composite intake manifold assembly for cracks or damage
^ The areas between the intake runners
^ The gasket sealing surfaces and grooves for cracking or damage
^ The fuel injector bores for excessive scoring or damage
^ The throttle body adapter heater plate for restrictions and/or corrosion
2. Inspect the following thread bolt inserts for looseness or damaged threads:
^ Throttle body
^ EVAP solenoid
^ EGR pipe
3. Inspect the intake manifold cylinder head deck for warpage.
3.1. Locate a straight edge across the intake manifold cylinder head deck surface.
3.2. Insert a feeler gauge between the intake manifold and the straight edge.
A intake manifold with warpage in excess of 0.5 mm (0.020 inch), must be replaced.
4. Repair or replace the intake manifold as necessary.