Engine Diagnosis - Introduction

This service category can be helpful in determining the causes of malfunctions not detected and remedied by routine maintenance.

These malfunctions are classified as Performance (e.g., engine idles rough and stalls) or Mechanical (e.g., a strange noise).

Refer to DIAGNOSIS AND TESTING  and refer to ENGINE MECHANICAL DIAGNOSTIC TABLE  for possible causes and corrections of malfunctions. Refer to 6.4L FUEL SYSTEM for the fuel system diagnosis.

Additional diagnosis and testing 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:

• Cylinder Compression Pressure Test. Refer to CYLINDER COMPRESSION TEST  .
• Cylinder Combustion Pressure Leakage Test. Refer to CYLINDER LEAKAGE TEST  .
• Engine Cylinder Head Gasket Failure Diagnosis. Refer to DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET FAILURE  .
• Intake Manifold Leakage Diagnosis. Refer to DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKAGE  .