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 Inspection
|
| • | 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 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. |
|
Fuel System Checks
|
| • | 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.
|
| 3. | Crank the engine while observing the glow plug 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. Refer to
Fuel in Engine Oil
in Engine Mechanical. |
|
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. |
| • | Compare the scan tool data at idle with the scan tool data list. Refer
to
Scan Tool Data List
. |
|
