Checks
| Action
|
Definition: A mild to severe ping, usually worse under acceleration. The engine
makes sharp metallic knocks that change with the throttle opening.
|
Preliminary Checks
|
| • | Make sure the vehicle has an actual problem. |
| • | Check the fuel quality. |
|
Cooling System Checks
|
| • | Check for obvious overheating problems. Refer to the appropriate service
manual. |
| • | Check for a low engine coolant level. |
| • | Check for a loose water pump belt. |
| • | Check for any restricted air flow through the radiator, or restricted
coolant flow. |
| • | Check for a malfunctioning or incorrect thermostat. |
| • | Check for a correct coolant solution. The solution should be a 50/50
mix of anti-freeze and water. |
|
Sensor Check
| Check the engine coolant temperature (ECT) sensor by using the scan tool in
order to compare the engine coolant temperature with the ambient air temperature
on a cold engine. If the coolant temperature reading is more than 5° greater
or less than the ambient air temperature on a cold engine, check for a high resistance
in the coolant sensor circuit or the sensor itself.
|
Fuel System Checks
|
|
Engine Mechanical Checks
|
| • | Check for incorrect basic engine parts such as cam, heads, pistons, etc. |
| • | Check for any excessive oil entering combustion chamber. |
|
Additional Checks
| Check the Service Bulletins for control module software updates.
|
