Intake Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the intake manifold for damage.
Inspect the intake manifold for cracks near the mounting holes (1-4).
Inspect the crankcase ventilation passages for any blockage and clean as necessary.

Fig 1: Inspecting Intake Manifold
Courtesy of GENERAL MOTORS CORP.
Clean the intake manifold mating surfaces.
Use a straight edge and a feeler gage and measure the intake manifold mounting surface for warpage.
Intake Manifold Maximum Warpage

0.10 mm (0.0039 in)
If the warpage is greater than the maximum, replace the intake manifold.

Fig 2: Checking Intake Manifold Mounting Surface
Courtesy of GENERAL MOTORS CORP.