Check
| 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 customer has an actual problem. |
• | Check the Transmission Range (TR) pressure switch assembly operation.
Refer to Transmission Fluid Pressure Switch Assembly. |
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Cooling
System Checks
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• | Check for a low engine coolant level. |
• | Check for the proper tension on the drive belts. |
• | Check for restricted air flow through the radiator, or restricted
coolant flow. |
• | Check for a faulty thermostat, refer to Diagnosis of the Thermostat
in Engine Cooling. |
• | Check for a correct coolant solution. |
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Sensor
Check
| Check
for an Engine Coolant Temperature (ECT) sensor that has a shift in value.
Refer to
DTC P1114 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage
Diagnostic Aids. Refer to
DTC P1115 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage
Diagnostic Aids.
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Fuel System Checks
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• | Check if a Lean system causes this condition. Drive the vehicle
at the speed of the complaint. Monitoring the Fuel Trim will help identify
the problem. |
• | Check for a poor fuel quality and a proper octane rating. |
• | If the scan tool readings are normal and there are no engine mechanical
faults, fill the fuel tank with a premium gasoline that has a minimum octane
rating of 92 and re-evaluate the vehicle's performance. |
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Ignition
System Checks
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• | Check the spark plugs for their proper heat range and gap. |
• | Check the ignition timing. |
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Engine
Mechanical Checks
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• | Check for carbon build up. Remove the carbon with a top engine
cleaner. Follow the instructions on the can. |
• | Check the combustion chamber pressure by performing a compression
test. Refer to Engine Mechanical. |
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Additional
Checks
|
• | Check for the proper operation of the transmission shift points.
Refer to the Transmission Controls section. |
• | Check the Torque Converter Clutch (TCC) operation. Refer to Torque
Converter Clutch Solenoid in Automatic Transmission. |
• | Check the Service Bulletins for PROM updates. |
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