Diagnostic Strategies

Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine maintenance.
These malfunctions may be classified as either mechanical (e.g., a strange noise), or performance (e.g., engine idles rough and stalls).
Refer to the Engine Diagnosis-Mechanical Chart Engine Diagnosis - Mechanical and the Engine Diagnosis-Performance Chart Engine Diagnosis - Performance, 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:
- Cylinder Compression Pressure Test
- Cylinder Combustion Pressure Leakage Test
- Engine Cylinder Head Gasket Failure Diagnosis
- Intake Manifold Leakage Diagnosis