Nearly all turbocharger-related problems are the result of a handful of causes. Knowing how to recognize the symptoms of these issues early and link them with causes will help you save time and money.

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 are often wrongly attributed to the turbocharger because defects in other components can produce the same symptoms. The turbocharger performance can only be impaired by mechanical damage or blockage caused by dirt

This checklist provides a comprehensive list of the most common symptoms related to turbocharger failure. BEFORE replacing a turbocharger, verify the problem by consulting the chart below. If after taking the appropriate action, problems still persist, please contact your nearest Diesel USA Group location for advice.

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
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Restricted compressor intake duct
Remove restriction or replace damaged parts as required
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Restricted air duct from compressor to intake manifold
Replace seals, gaskets or tighten fasteners as required
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Restricted intake manifold
Refer to engine manufacturer’s manual and remove restriction
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Air leak in feed from air cleaner to compressor
Replace seals, gaskets or tighten fasteners as required
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Air leak in feed from compressor to intake manifold
Replace seals, gaskets or tighten fasteners as required
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Air leak between intake manifold and engine
Refer to engine manufacturer’s manual and replace gaskets or tighten fasteners as required
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Foreign object in exhaust manifold (from engine)
Refer to engine manufacturer’s manual and remove obstruction
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Restricted exhaust system
Remove restriction or replace damaged parts as required
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Exhaust manifold cracked, gaskets blown or missing
Refer to engine manufacturer’s manual and replace gaskets or damaged parts as required
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Gas leak at turbine inlet/exhaust manifold joint
Replace gasket or tighten fasteners as required
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Gas leak in ducting after turbine outlet
Refer to engine manufacturer’s manual and repair leak
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Restricted turbocharger oil drain line
Remove restriction or replace damaged parts as required
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Restricted engine crankcase breather
Refer to engine manufacturer’s manual, clear restriction
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Turbocharger bearing housing sludged or coked
Change engine oil and oil filter, overhaul or replace turbocharger as required
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Fuel injection pump or fuel injectors incorrectly set
Refer to engine manufacturer’s manual and replace or adjust faulty components as required
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Engine valve timing incorrect
Refer to engine manufacturer’s manual for correct settings and adjust as required
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Worn engine piston rings or liners
Refer to engine manufacturer’s manual and repair as required
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Burnt valves and/or pistons
Refer to engine manufacturer’s manual and repair as required
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Excessive dirt build-up on impeller and/or diffuser vanes
Clean in accordance with the appropriate manufacturer repair manual
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Turbocharger damaged
Find and correct cause of failure, repair or replace turbocharger as necessary
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Failed diaphragm
Replace using correct Actuator Service Kit
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Siezed valve
Free valve/replace complete turbine housing sub-assembly
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Leaking hose
Replace hose and clips
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Wastegate mechanism set incorrectly
Contact our Diesel USA Group location you for details on proper settings
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