Checks
| Action
|
DEFINITION: A mild
to severe ping, usually worse under acceleration. The engine makes sharp metallic
knocks that change with the throttle opening.
|
Preliminary Checks
|
| • | Ensure the vehicle has an actual problem. |
| • | Inspect for smoke associated with the combustion noise. Refer
to Fuel System Checks below. |
|
Cooling System Checks
|
| • | 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. |
|
Sensor Check
|
| • | 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 the engine OFF. FRP should be near 1.4 MPa.
If not , check for high resistance in the low reference or 5-volt reference
circuits or the sensor. |
| • | Inspect for an intermittent crankshaft position (CKP) sensor signal. |
|
Fuel System Checks
|
| • | If excessive smoke is present, check 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.
|
| 3. | Crank the engine while observing the holes for fuel spray. |
| 4. | Replace the fuel injectors for the cylinders that spray fuel. |
| 5. | Check for fuel in the oil and proper oil level. Change the oil
as necessary. |
| • | Inspect for plugged fuel injectors. |
|
Engine Mechanical
Checks
|
| • | Inspect for incorrect basic engine parts such as cam, heads, pistons,
etc. |
| • | Inspect for any excessive oil entering combustion chamber. |
|
Additional Checks
| Review the Service Bulletins for control module software updates.
|
