Checks
| Action
|
Definition:
A mild to severe ping which is usually worse upon acceleration. The engine
makes sharp metallic knocks which change with the throttle opening.
|
Preliminary Checks
|
| • | Make sure the vehicle has an actual problem. |
| • | Check the fuel quality. Refer to Fuel Systems. |
|
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 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. Use 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 the cam, the heads,
the pistons, etc. |
| • | Check for any excessive oil entering the combustion chamber. |
|
Additional Checks
| Check the Service Bulletins
for control module software updates.
|
