Engine Noise Under Load

Cause	Correction
Low oil pressure	Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . Repair or replace, as required.
Detonation or spark knock	Verify the correct operation of the ignition controls. Refer to Detonation/Spark Knock in Engine Controls - 4.8L, 5.3L, and 6.0L.
Loose torque converter bolts	Inspect the torque converter bolts and flywheel. Repair, as required.
Cracked flywheel - automatic transmission	Inspect the flywheel bolts and flywheel. Repair, as required.
Excessive connecting rod bearing clearance	Inspect the following components and repair, as required: The connecting rod bearings The connecting rods The crankshaft
Excessive crankshaft bearing clearance	Inspect the following components and repair, as required: The crankshaft bearings The crankshaft journals The cylinder block crankshaft bearing bore
Loose or damaged RPO HP2 flex plate	Repair or replace flex plate.
Loose or damaged RPO HP2 stator or rotor	Inspect the stator and rotor. Repair or replace, as required.