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. Refer to |
|
Cooling System Checks
|
| • | Check for obvious overheating problems. Refer to the appropriate
service manual. |
| • | Check for a low engine coolant level. |
| • | Check for improper belt routing. |
| • | Check for 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
|
| • | Check for air leaks in the fuel supply to the injection pump.
Refer to |
| • | Check the injection pump static timing. Refer to . |
| • | Check the injection nozzles. Refer to |
|
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.
|
