Checks
| Action
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Definition: A mild to severe ping, usually worse under acceleration. The engine
makes sharp metallic knocks that change with the throttle opening.
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Preliminary Checks
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• | Make sure the vehicle has an actual problem. |
• | Check the fuel quality. |
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Cooling System Checks
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• | 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. |
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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.
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Fuel System Checks
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• | Check the injection nozzles. |
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Engine Mechanical Checks
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• | Check for incorrect basic engine parts such as cam, heads, pistons, etc. |
• | Check for any excessive oil entering combustion chamber. |
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Additional Checks
| Check the Service Bulletins for control module software updates.
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