Diagnostic Strategies

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 applicable Diagnosis Charts for possible causes and corrections of malfunctions.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that cannot be isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the following diagnosis:
- Cylinder Compression Pressure Test: Refer to Compression Check.
- Cylinder Combustion Pressure Leakage Test: Refer to Cylinder Combustion Pressure Leakage.
- Engine Cylinder Head Gasket Failure Diagnosis: Refer to Cylinder Head Gasket; Testing and Inspection.
- Intake Manifold Leakage Diagnosis: Refer to Intake Manifold; Testing and Inspection.