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Lower Engine Noise, Regardless of Engine Speed (LDK, LHU)

Lower Engine Noise, Regardless of Engine Speed (LDK, LHU)


Cause Correction
Low oil pressure


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

2. Repair or replace damaged components, as required.


Worn accessory drive components - abnormalities, such as severe cracking, bumps, or missing areas in the accessory drive belt and/or misalignment of system components


1. Inspect the accessory drive system.

2. Repair or replace, as required.


Loose or damaged crankshaft balancer


1. Inspect the crankshaft balancer.

2. Repair or replace, as required.


Detonation or spark knock

Verify the correct operation of the ignition system. Refer to Symptoms - Engine control .

Loose torque converter bolts


1. Inspect the torque converter bolts and flywheel.

2. Repair or replace, as required.


Loose or damaged flywheel

Repair or replace the flywheel.

Damaged oil pan, contacting the oil pump screen

An oil pan that has been damaged, may improperly position the oil pump screen, preventing proper oil flow to the oil pump.


1. Inspect the oil pan.

2. Inspect the oil pump screen.

3. Repair or replace, as required.


Oil pump screen loose, damaged, or restricted


1. Inspect the oil pump screen.

2. Repair or replace, as required.


Excessive piston-to-cylinder bore clearance


1. Inspect the piston and cylinder bore.

2. Repair, as required.


Excessive piston pin-to-bore clearance


1. Inspect the piston, piston pin, and the connecting rod.

2. Repair or replace, as required.


Excessive connecting rod bearing clearance

Inspect the following components and repair, as required:


The connecting rod bearings

The connecting rods

The crankshaft

The crankshaft journals


Excessive crankshaft bearing clearance

Inspect the following components and repair, as required:


The crankshaft bearings

The crankshaft journals


Incorrect piston, piston pin, and connecting rod installation

Pistons must be installed with the mark or dimple on the top of the piston facing the front of the engine. Piston pins must be centered in the connecting rod pin bore.


1. Verify the pistons, piston pins, and connecting rods are installed correctly.

2. Repair, as required.