Low oil pressure.

Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing.

Detonation or spark knock.

Verify the correct operation of the ignition controls system. Refer to Diagnostic Starting Point - Engine Controls.

Loose torque converter bolts.

1. Inspect the torque converter bolts and flex plate. Refer to Flex Plate/Torque Converter Vibration Test for 5L40-E/5L50-E.

or

Refer to Flex Plate/Torque Converter Vibration Test for 6L50/6L80/6L90.

2. Repair or replace, as required. Refer to Torque Converter Replacement for 5L40-E/5L50-E.

or

Refer to Torque Converter Replacement for 6L50/6L80/6L90.

or

Refer to Engine Flywheel Replacement.

Cracked flywheel - automatic transmission.

Repair or replace the flywheel. Refer to Engine Flywheel Replacement.

Above acceptable connecting rod bearing clearance.

Inspect the following components and repair, as required:

Refer to Piston, Connecting Rod, and Bearing Removal.

Above acceptable crankshaft bearing clearance.

Inspect the following components and repair, as required:

Refer to Piston, Connecting Rod, and Bearing Removal.

Low oil pressure

1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing.
2. Repair or replace, as required.

Detonation or spark knock

Verify the correct operation of the ignition controls. Refer to Diagnostic Starting Point - Engine Controls.

Loose torque converter bolts

1. Inspect the torque converter bolts and flex plate.
2. Repair, as required.

Cracked flex plate - automatic transmission

1. Inspect the bolts and flex plate.
2. Repair, as required.

Excessive connecting rod bearing clearance

Inspect the following components and repair, as required:

Excessive crankshaft bearing clearance

Inspect the following components and repair, as required: