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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• | Ensure the vehicle has an actual problem. |
• | Inspect for smoke associated with the combustion noise. Refer to Fuel System Checks below. |
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Cooling System Checks
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• | Inspect for obvious overheating problems. Refer to
Engine Overheating
in Engine Cooling. |
• | Inspect for a low engine coolant level. |
• | Inspect for any restricted air flow through the radiator. Refer to
Radiator Cleaning
in Engine Cooling. |
• | Inspect for a malfunctioning or incorrect thermostat. |
• | Inspect for a correct coolant solution. The solution should be a 50/50 mix of anti-freeze and water. |
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Sensor inspection
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• | Inspect the engine coolant temperature (ECT) sensor by using the scan tool in order to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more 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. |
• | Inspect the fuel rail pressure (FRP) sensor. Use the scan tool to observe FRP with ignition ON and the engine OFF. FRP should be 1.1-1.4 MPa. If FRP is not within this range, check for high resistance in the low reference or 5-volt reference
circuits or the sensor, or a faulty sensor. |
• | Inspect the crankshaft position (CKP) sensor reluctor wheel. Remove the CKP sensor and attempt to move the reluctor wheel front to back or side to side with a probe. If there is any movement the reluctor wheel retaining bolts are loose. |
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Fuel System Checks
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• | If excessive smoke is present, check for a stuck open fuel injector by performing the following procedure: |
1. | Remove the ignition 1 relay. |
| Important: Do not stand in front of the glow plug holes while cranking the engine.
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3. | Crank the engine while observing the glow plug holes for fuel spray. |
5. | Check for fuel in the oil and proper oil level. Refer to
Fuel in Engine Oil
in Engine Mechanical. |
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Engine Mechanical Checks
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• | Inspect for incorrect basic engine parts such as cam, heads, pistons, etc. |
• | Inspect for any excessive oil entering combustion chamber. |
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Additional Checks
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• | Review the Service Bulletins for control module software updates. |
• | Compare the scan tool data at idle with the scan tool data list. Refer to
Scan Tool Data List
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