A faulty or damaged turbocharger can do more than just rob your diesel engine of needed power boost. If left untreated, it can easily lead to total engine failure and very expensive additional engine component damage. So it’s important that you be able to identify any problems in your turbocharger, and their potential causes before they get more serious, and more costly.
Engine Lacks Power
If your engine is lacking in power, there are several possible causes other than your turbocharger. Check first to make certain that there are no airflow issues. Make sure that the air cleaner is clean, replaced regularly per manufacturer recommendations, using OEM replacement parts. Check fuel injectors and fuel pump for adequate flow; make sure ignition timing is set to manufacturer specs. If you suspect the trouble is with the turbocharger, examine the impeller blades for any wear or damage. This is usually indicative of foreign objects getting into the turbo housing.
Turbo Unit Seized
When the turbocharger seizes up, or works sluggishly, a likely cause is poor lubrication or damage to the unit. If the rotor assembly doesn’t rotate freely, it could indicate a high buildup of carbon in the assembly. This could be the result of low oil pressure, dirty or degraded lubricating oil. Check oil for dirt or contaminants, replace per recommended intervals with the appropriate grade lube oil.
Improper Rotor Clearance
Regardless of the make and model of an engine, each turbocharger assembly has very specific tolerances with regard to the clearances for its rotors. Deviations from these clearances will adversely affect engine performance and can be due to defective bearings, or poor or dirty lubricant oil. Check as above for dirty, insufficient or degraded lubricant.
Noisy / Whistling Turbo
When a turbocharger whistles or produces excessive noise, the cause is most often an air or gas leak, or a leak in the EGR cooler. Check for air leaks, broken, missing or worn gaskets, etc. As above, check for proper clearances.