Check Cylinder Performance
If KOER CYLINDER CONTRIBUTION SELF-TEST under QUICK TEST in TESTS W/CODES - 7.3L DIESEL article has been successfully completed previously, go to CHECK FOR EXHAUST RESTRICTION . If KOER CYLINDER CONTRIBUTION SELF-TEST has not been completed, perform KOER CYLINDER CONTRIBUTION SELF-TEST. Possible causes for failing this test are:
- Broken compression rings.
- Burnt or bent valve.
- Bent push rods.
- Bent connecting rods.
- Damaged rocker arms.
- Faulty fuel injector assembly.