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). For possible causes and corrections of malfunctions, refer to ENGINE MECHANICAL DIAGNOSIS CHART .

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that can not be isolated with the Service Diagnosis charts. For additional Information on diagnosis and testing, refer to the following tests:

• Cylinder Compression Pressure Leakage. Refer to CYLINDER COMPRESSION PRESSURE LEAKAGE .
• Cylinder Combustion Pressure Leakage. Refer to CYLINDER COMBUSTION PRESSURE LEAKAGE .
• Checking Engine Oil Pressure. Refer to CHECKING ENGINE OIL PRESSURE .
• Cylinder Head Gasket Failure. Refer to DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET FAILURE .
• Intake Manifold Leakage. Refer to DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKAGE .