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 condition. |
| • | Inspect for smoke associated with the combustion noise. |
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Cooling System Checks
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| • | Inspect for a low engine coolant level. |
| • | Inspect for any restricted air flow through the radiator. Refer to
Radiator Cleaning
. |
| • | 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 Check
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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, inspect 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 the engine OFF. FRP should be near 1.4 MPa. If not , inspect for high resistance in the low reference or 5-volt reference circuits or the sensor. |
| • | Inspect for an intermittent crankshaft position (CKP) sensor signal. |
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Fuel System Checks
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| • | If excessive smoke is present, inspect for a stuck open fuel injector. |
| 1. | Disconnect all of the fuel injector electrical connectors. |
| 2. | Remove the glow plugs. |
| | 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 holes for fuel spray. |
| 4. | Replace the fuel injectors for the cylinders that spray fuel. |
| 5. | Inspect for fuel in the oil and proper oil level. Change the oil, as necessary. |
| • | Inspect for plugged fuel injectors. |
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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
| Review the Service Bulletins for control module software updates.
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