Engine Diagnosis - Introduction

Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine maintenance.

These malfunctions may be classified as either performance (e.g, engine idles rough and stalls) or mechanical (e.g, a strange noise).

See ENGINE PERFORMANCE DIAGNOSTIC TABLE  or ENGINE MECHANICAL DIAGNOSTIC TABLE  for possible causes and corrections of malfunctions. Refer to FUEL SYSTEM for the fuel system diagnosis.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that can not be isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the following diagnosis:

1. Cylinder Compression Pressure Test. See CYLINDER COMPRESSION PRESSURE LEAKAGE .
2. Cylinder Combustion Pressure Leakage Test. See CYLINDER COMBUSTION PRESSURE LEAKAGE .
3. Engine Cylinder Head Gasket Failure Diagnosis. See CYLINDER HEAD GASKET .
4. Intake Manifold Leakage Diagnosis. See INTAKE MANIFOLD LEAKS .