6.7L Cummins Troubleshooting – Air Compressor Noise is Excessive

Carbon buildup is excessive in the air discharge line or downstream air valves

Check for carbon buildup. Clean or replace the air compressor discharge line, as necessary. Check the turbocharger for oil leaks. Check the air compressor intake tube for oil. Refer to Procedure 012-003 in Section 12.

Ice buildup in the air system components

For all models, check for ice in low spots of the air discharge line, dryer inlet, and elbow fittings. On Holsetยฎ models, also check the Econ valve, if equipped. Refer to the OEM instructions.

Air compressor mounting hardware is loose, worn, or broken

Check the air compressor mounting hardware. Refer to Procedure 012-014 in Section 12.

Air compressor is sending air pulses into the air tanks

Install a ping tank between the air dryer and the wet tank. Refer to the OEM instructions.

Splined drive coupling or gear is excessively worn

Check the coupling for wear. Refer to Procedure 012-014 in Section 12.

Air compressor drive gear or engine gear train is worn or damaged

Inspect the drive gears and gear train and repair as necessary. Refer to Procedure 012-014 in Section 12 to remove the air compressor and inspect the air compressor drive gear. Repair as necessary.

Air compressor is excessively worn or internally damaged

Inspect the air compressor for internal damage. Refer to Procedure 012-014 in Section 12. Replace the desiccant element on the Turbo/CR 2000 air sryer (if equipped). Refer to the manufacturer’s instructions.