Inspection Procedure

WARNING: This page is about a different variant/trim than selected.

Inspect the throttle body studs and threaded inserts for looseness or damaged threads.

Fig 1: View Of Throttle Body & Nuts

Courtesy of GENERAL MOTORS CORP.

Inspect the wire harness stud and threaded insert for looseness or damaged threads.
Inspect the fuel rail bolt inserts for looseness or damaged threads.

Fig 2: View Of Fuel Rail W/Injectors

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Inspect the intake manifold vacuum passages for debris or restrictions.
Inspect for damaged or broken vacuum fittings, damaged MAP sensor (714) mounting bore, or broken MAP sensor retaining tabs.

Fig 3: View Of MAP Sensor

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Inspect the composite intake manifold assembly for cracks or other damage.
Inspect the areas between the intake runners.
Inspect all the gasket sealing surfaces for damage.
Inspect the fuel injector bores for excessive scoring or damage.
Inspect the intake manifold cylinder head deck for warpage.
1. Locate a straight edge across the intake manifold cylinder head deck surface.
  Position the straight edge across a minimum of two runner port openings.
2. Insert a feeler gage between the intake manifold and the straight edge.
  A 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.

Fig 4: Inspecting Intake Manifold Cylinder Head Deck For Warpage

Courtesy of GENERAL MOTORS CORP.

Fig 5: View Of MAP Sensor

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NOTE: Refer to Fastener Notice in Cautions and Notices.

Install the EVAP solenoid, bolt, and isolator.
Tighten: Tighten the EVAP solenoid bolt to 10 N.m (89 lb in).