Base Engine Misfire without Internal 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 and lead to a misfire DTC. 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 may lead to a misfire DTC. A misfire code may be present without an actual misfire condition.	Inspect the components and repair or replace as required.
Loose or improperly installed 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 and repair or replace as required.
Loose or improperly installed engine flywheel A misfire code may be present without an actual misfire condition.	Repair or replace the flywheel and/or balancer as required.
Restricted exhaust system A severe restriction in the exhaust flow can cause significant loss of engine performance and may set a DTC. Possible causes of restrictions include collapsed or dented pipes or plugged mufflers and/or catalytic converters.	Repair or replace as required.
Air in fuel system	Inspect fuel filter, fuel system for leaks and/or restrictions and repair or replace as required.
Bent and/or worn valve pushrod	Inspect valve pushrod and valve rocker arm and repair or replace as required.
Worn or loose rocker arms The rocker arm bearing end caps and/or needle bearings should be intact and in the proper position.	Replace the valve rocker arms as required.
Improperly installed or damaged vacuum hoses	Repair or replace as required.
Improper sealing between the intake manifold and cylinder heads or throttle body.	Replace the intake manifold, gaskets, cylinder heads and/or throttle body as required.
Sticking valve Carbon buildup on the valve stem can cause the valve not to close properly.	Repair or replace as required.
Excessively worn or mis-aligned timing belt	Replace the timing belt and sprockets as required.
Damaged or misaligned timing gears	Inspect timing gears and replace as required.
Worn or faulty camshaft lobes	Replace the camshaft and valve lash adjusters.
Excessive oil pressure A lubrication system with excessive oil pressure may lead to excessive valve lifter pump up and loss of compression.	Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . Repair or replace the oil pump as required.
Faulty cylinder head gasket and/or cracking or other damage to the cylinder head and engine block cooling system passages Coolant consumption may or may not cause the engine to overheat.	Inspect the cylinder head, engine block and/or head gasket. 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 identify the cause. Repair or replace 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. Refer to Fuel in Engine Oil . Repair any fuel leaks.