Base Engine Misfire with Abnormal Internal Lower Engine Noises

WARNING: This page is about a different variant/trim than selected.

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 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.
Loose torque converter bolts A misfire code may be present without an actual misfire condition.	Inspect the torque converter bolts and flywheel. Repair or replace as required.
Worn piston rings Oil consumption may or may not cause the engine to misfire.	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 misfire code without an actual misfire condition.	Replace the crankshaft and bearings as required.
Overfilled crankcase	Check engine oil level with vehicle on a level surface. Correct any overfilled condition. Inspect for fuel leaks into the crankcase. Repair any fuel leaks.