Base Engine Misfire with Abnormal Internal Lower Engine Noises. Chevrolet Cruze (GME) 2010

For 1990-2009 cars

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.

Worn piston rings

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.