12c. Check Valve Operation Test
12c. CHECK VALVE OPERATION TESTPurpose:
This purpose of this test is to verify operation of the oil rail check valves.
Check Valve Operation Test
- Key ON, engine running.
- Access and monitor the EOT PID. The engine oil temperature must be above 80°c (176°F).
- Carry out a slow RPM run up in park or neutral.
- If the engine runs rough between 1,200 RPM and 2,300 RPM, verify the check valve operation.
6.0L Engine, Cylinder And Fuel Injector Location:
Recommended Procedure:
Verify the operation of the bank 2 check valve by disconnecting all bank 1 fuel injectors.
With the bank 1 fuel injectors disconnected, use the scan tool to monitor cylinder contribution using the Power Balance Test. Refer to the Power Balance Test. 6b. Power Balance Test
The cylinders with the fuel injectors connected should be contributing evenly.
Erratic contribution from the connected fuel injectors indicates the check valve on that bank is not seating correctly.
Connect the bank 1 fuel injectors.
Disconnect the bank 2 injectors and repeat the procedure to verify the operation of the bank 1 check valve.
Possible Causes:
Damaged high pressure oil rail check valve.
Tools Required:
Scan Tool