Strategy Based Diagnostics
- Perform A Diagnostic Starting Point - Engine Mechanical
in Engine Controls before using the symptom tables (if applicable).
- Review the system operations in order to familiarize yourself
with the system functions. Refer to Disassembled Views, Engine Component Description,
Drive Belt System Description, Lubrication Description and New Product Information
in Engine Mechanical.
All diagnosis on a vehicle should follow a logical process. Strategy
based diagnostics is a uniform approach for repairing all systems. The diagnostic
flow may always be used in order to resolve a system problem. The diagnostic
flow is the place to start when repairs are necessary. For a detailed explanation,
refer to Strategy Based Diagnostics in General Information.
Visual/Physical Inspection
| • | Inspect for aftermarket devices which could affect the operation
of the Engine. Refer to Checking Aftermarket Accessories in Wiring Systems. |
| • | Inspect the easily accessible or visible system components for
obvious damage or conditions which could cause the symptom. |
| • | Check for the correct oil level, proper oil viscosity, and correct
filter application. |
| • | Verify the exact operating conditions under which the concern
exists. Note factors such as engine RPM, ambient temperature, engine temperature,
amount of engine warm-up time, and other specifics. |
| • | Compare the engine sounds (if applicable) to a known good engine
and make sure you are not trying to correct a normal condition. |
Intermittent
Test the vehicle under the same conditions that the customer reported
in order to verify the system is operating properly.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order
to diagnose the symptom:
| • | Base Engine Misfire without Internal Engine Noises |
| • | Base Engine Misfire with Abnormal Internal Lower Engine Noises |
| • | Base Engine Misfire with Abnormal Valve Train Noise |
| • | Base Engine Misfire with Coolant Consumption |
| • | Base Engine Misfire with Excessive Oil Consumption |
| • | Engine Noise on Start-Up, but Only Lasting a Few Seconds |
| • | Upper Engine Noise, Regardless of Engine Speed |
| • | Lower Engine Noise, Regardless of Engine Speed |
| • | Engine Noise Under Load |
| • | Engine Will Not Crank - Crankshaft Will Not Rotate |
| • | Oil Consumption Diagnosis |
| • | Oil Pressure Diagnosis and Testing |
