Inspections
| 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
|
| • | Verify the customer's concern. |
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Cooling System
|
| • | Inspect for a low engine coolant level. |
| • | Inspect for a correct coolant mixture. |
| • | Inspect for restricted air flow through the radiator, or restricted coolant flow. |
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Sensor/System
| Inspect for an engine coolant temperature (ECT) sensor that has a shift in value. Refer to
Temperature Versus Resistance
.
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Fuel System
|
| • | Drive the vehicle at the speed of the complaint. Monitoring the fuel trim will help identify the problem. |
| • | If the system is lean, the long term fuel trim will be more than 150. |
| • | Inspect for a poor fuel quality and a proper octane rating. |
| • | If the fuel trim readings are normal and there are no engine mechanical concerns, then fill the fuel tank with a known good fuel and re-evaluate the vehicle performance. |
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Ignition System
|
| • | Inspect the spark plugs for their proper heat range and gap. |
| • | Inspect the knock sensor (KS) system operation. |
| • | Inspect the ignition timing. |
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Engine Mechanical
|
| • | Inspect for carbon build up. Remove the carbon with a top engine cleaner. Follow the instructions on the can. |
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Additional
|
| • | Search for Service Bulletins for calibration updates. |
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