Section 03-00: Engine—Service
1994 Mustang Workshop Manual
SERVICE PROCEDURES

Oil Leak and Valve Guide Seal Test

The cylinder leakage detector can be used to test for engine oil leaks and to check the valve stem seal (6571) for leakage.

  1. Plug all crankcase openings except the one used for connecting the leakage detector.
  1. Connect the detector to a crankcase opening ( oil level indicator tube (6754) is convenient) and adjust the air pressure to approximately 34 kPa (5 psi).
  1. Using a solution of liquid soap and water, brush the solution along gasket sealing surfaces and crankshaft seals. Look for bubbles or foam.
  1. Remove the spark plugs (12405) and rotate the engine slowly with a wrench. Check for large amounts of air escaping into the cylinders as each exhaust valve (6505) and intake valve (6507) opens.

    The spark plugs on the leaking cylinders will probably show deposits of burned oil.