Intake Manifold: Testing and Inspection

LEAKAGE DIAGNOSIS
An intake manifold air leak is characterized by lower than normal manifold vacuum. Also, one or more cylinders may not be functioning.

WARNING: Use extreme caution when the engine is operating. Do not stand in a direct line with the fan. Do not put your hands near the pulleys, belts or the fan. do not wear loose clothing.

1. Start the engine.
2. Spray a small stream of water (Spray Bottle) at the suspected leak area.
3. If a change in RPM'S, the area of the suspected leak has been found.
4. Repair as required.

GENERAL INSPECTION
Check for:
^ Damage and cracks of each section.
^ Clogged water passages in end crossovers (if equipped).
^ Check for cylinder head mounting surface distortion using a straightedge and thickness gauge.

CLEANING
Remove the gasket material from the manifold surfaces. Be careful not to gouge or scratch the sealing surface.