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Turbocharger Troubleshooting

Related: Garrett | Holset | IHI | Mitsubishi | BorgWarner | Mopar

OEM turbos are made to highly specific standards, not only to deliver the power owners demand, but also to keep diesel and gas engines performing at top efficiency year after year. With correct parts and regular maintenance, drivers who utilize turbocharged engines can depend on the performance and efficiency their vehicles were designed to deliver over the long haul.

Loss of power, excess smoke, high fuel consumption, overheating, high exhaust temperatures and oil leakages from the turbocharger are all symptoms that could indicate turbocharger malfunction. However, these faults can often wrongly be attributed to the turbocharger, as defects in other components can also produce the same symptoms.

Diagnosing a damaged turbocharger can be complicated, but there are many ways your vehicle will let you know that it is having issues with the turbo. All too frequently however, serviceable turbochargers are removed from engines before the cause of the problem has been determined. Always inspect and assess the turbochargers condition before removal from the engine. As always seek the advice of trained professionals before modifying or attempting to self-repair your turbocharged vehicle.

Warning: Self attempted turbocharger maintenance and repair could void your original equipment product warranty. This guide is provided purely as an informational resource, Diesel USA is not responsible for any damage caused by self-attempted repairs or replacements.

Possible Failure Diagnosis Engine Running Hot Poor Transient Response Smoke Engine Lacks Power Black Exhaust Smoke Blue Exhaust Smoke High Oil Consumption Turbocharger Noisy Cyclic Sound from the Turbocharger Oil Leak from Compressor Seal Oil Leak from Turbine Seal
Dirty air cleaner
Clean or replace element according to manufacturer’s recommendations		 ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔
Restricted compressor intake duct
Remove restriction or replace damaged parts as required		 ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔
Restricted air duct from compressor to intake manifold
Replace seals, gaskets or tighten fasteners as required		 ✔ ✔ ✔ ✔ ✔
Restricted intake manifold
Refer to engine manufacturer’s manual and remove restriction		 ✔ ✔ ✔ ✔ ✔
Air leak in feed from air cleaner to compressor
Replace seals, gaskets or tighten fasteners as required		 ✔
Air leak in feed from compressor to intake manifold
Replace seals, gaskets or tighten fasteners as required		 ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔
Air leak between intake manifold and engine
Refer to engine manufacturer’s manual and replace gaskets or tighten fasteners as required		 ✔ ✔ ✔ ✔ ✔ ✔ ✔
Foreign object in exhaust manifold (from engine)
Refer to engine manufacturer’s manual and remove obstruction		 ✔ ✔ ✔ ✔ ✔ ✔
Restricted exhaust system
Remove restriction or replace damaged parts as required		 ✔ ✔ ✔ ✔
Exhaust manifold cracked, gaskets blown or missing
Refer to engine manufacturer’s manual and replace gaskets or damaged parts as required		 ✔ ✔ ✔ ✔ ✔
Gas leak at turbine inlet/exhaust manifold joint
Replace gasket or tighten fasteners as required		 ✔ ✔ ✔ ✔ ✔
Gas leak in ducting after turbine outlet
Refer to engine manufacturer’s manual and repair leak		 ✔ ✔
Restricted turbocharger oil drain line
Remove restriction or replace damaged parts as required		 ✔ ✔ ✔ ✔
Restricted engine crankcase breather
Refer to engine manufacturer’s manual, clear restriction		 ✔ ✔ ✔ ✔
Turbocharger bearing housing sludge or coked
Change engine oil and oil filter, overhaul or replace turbocharger as required		 ✔ ✔ ✔ ✔
Fuel injection pump or fuel injectors incorrectly set
Refer to engine manufacturer’s manual and replace or adjust faulty components as required		 ✔ ✔ ✔ ✔
Engine valve timing incorrect
Refer to engine manufacturer’s manual for correct settings and adjust as required		 ✔ ✔
Worn engine piston rings or liners
Refer to engine manufacturer’s manual and repair as required		 ✔ ✔ ✔ ✔ ✔ ✔
Burnt valves and/or pistons
Refer to engine manufacturer’s manual and repair as required		 ✔ ✔ ✔ ✔ ✔ ✔
Excessive dirt build-up on impeller and/or diffuser vanes
Clean in accordance with the appropriate manufacturer repair manual		 ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔
Turbocharger damaged
Find and correct cause of failure, repair or replace turbocharger as necessary		 ✔ ✔ ✔ ✔ ✔ ✔ ✔
Failed diaphragm
Replace using correct Actuator Service Kit		 ✔ ✔
Seized valve
Free valve/replace complete turbine housing sub-assembly		 ✔ ✔
Leaking hose
Replace hose and clips		 ✔ ✔
Wastegate mechanism set incorrectly
Contact any Diesel USA Group location for more.		 ✔ ✔ ✔ ✔ ✔

Turbocharger Maintenance Tips:

Help Your Turbocharger Last: Through proper maintenance and care of your turbocharger it can and will last. More specifically, keeping your oil and filters changed regularly is crucial to the life of your turbocharger.

Let Your Turbocharger Cool Down: Most turbochargers utilize the oil from your engine for cooling, when turning off your engine before letting your turbocharger cool down you are allowing the opportunity for oil to become trapped in your turbocharger. When this oil cools it can then solidify, causing sludge buildup inside of your turbocharger allowing for pre-mature wear and failure of its internal components.


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