Diagnosis And Testing - 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).

(Refer to DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE ) and (Refer to DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL  or DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL ) for possible causes and corrections of malfunctions. (Refer to FUEL SYSTEM/FUEL DELIVERY - DIAGNOSIS AND TESTING) and FUEL INJECTION - EXCEPT DIESEL 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 (Refer to DIAGNOSIS AND TESTING - CYLINDER COMPRESSION PRESSURE ).
2. Cylinder Combustion Pressure Leakage Test (Refer to DIAGNOSIS AND TESTING - CYLINDER COMBUSTION PRESSURE LEAKAGE .
3. Engine Cylinder Head Gasket Failure Diagnosis (Refer to DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET FAILURE .
4. Intake Manifold Leakage Diagnosis (Refer to DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKAGE .