Cause
| Correction
|
| • | Abnormalities, severe cracking, bumps or missing areas in the accessory drive belt. |
| • | Abnormalities in the accessory drive system and/or components may cause engine revolutions per minute (RPM) variations, noises similar to a faulty lower engine, and also lead to a misfire condition. A misfire code may be present without an actual misfire condition. |
| Replace the drive belt.
|
| • | Worn, damaged, or mis-aligned accessory drive components or excessive pulley runout. |
| • | A misfire code may be present without an actual misfire condition. |
| Inspect the components, repair or replace as required.
|
| • | Loose or improperly installed engine flywheel or crankshaft balancer. |
| • | A misfire code may be present without an actual misfire condition. |
| Repair or replace the flywheel and/or balancer as required.
|
| • | Oil consumption may or may not cause the engine to misfire. |
|
- Inspect the spark plugs for oil deposits.
- Inspect the cylinders for a loss of compression. Refer to Engine Compression Test .
- Perform cylinder leak down and compression testing to determine the cause.
- Repair or replace as required.
|
| • | Worn crankshaft thrust bearings. |
| • | Severely worn thrust surfaces on the crankshaft and/or thrust bearing may permit fore and aft movement of the crankshaft, and create a diagnostic trouble code (DTC) without an actual misfire condition. |
| Replace the crankshaft and bearings as required.
|
