- Clean the intake manifold mating surfaces.
- Inspect the intake manifold for damage.
- Inspect the intake manifold for cracks near metallic inserts.
- Inspect the crankcase ventilation passages in the intake manifold face for blockage.
Warning: Refer to Safety Glasses Warning in the Preface section.
- Clean the crankcase ventilation passages with compressed air if necessary. Use a maximum of 172 kPa (25 psi) of air pressure.
- Replace the intake manifold as necessary.