Turbocharged Vehicle Fault Diagnostics

My turbo is leaking oil, is it the turbo?

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 carbonisation. 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 a problem(s) still persists please contact us.

Engine Running Hot

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Restricted Air Outlet Duct from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Restricted Inlet Manifold:	Refer to OEM’s Manual and Remove Restriction
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Restricted Exhaust System (back-pressure):	Refer OEM’s Manual Replace Gaskets or Tighten Fasteners as Required
Air/Fuel Ratio Incorrect:	Check AFR and Correct Cause
Ignition or Engine Vlave Timing Incorrect:	Refer OEM’s Manual, Adjust Timing(s) as Required
Failed Actuator Diaphragm:	Replace using Service Kit (pending model) or New Actuator
Siezed Swing-Valve:	Free valve or Replace Sub-Assembly or Complete Turbine Housing
Leaking Actuator Hose:	Replace Hose and Clips
Actuator / Wastegate Set Incorrectly:	Contact OEM or Turbo Specialist for Correct Settings

Poor Transient Response / Power Surge

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Restricted Air Outlet Duct from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as required
Restricted Inlet Manifold:	Refer to OEM’s Manual and Remove Restriction
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Exhaust Manifold Cracked, Gaskets Blown or Missing:	Refer to OEM’s Manual and Replace Gaskets or Damaged Parts as Required
Exhaust Gas Leak at Turbine Inlet / Exhaust Manifold Joint:	Replace Gasket or Tighten Fasteners as Required / Check Surfaces are Square
Exhaust Gas Leak in Tubing after Turbine Outlet:	Refer to OEM’s Manual and Repair Leak
Fuel Injection Pump or Fuel Injectors Incorrectly Set:	Refer to OEM’s’s Manual and Replace or Adjust Faulty Components
Air/Fuel Ratio Incorrect:	Check AFR and Correct Cause
Siezed Swing-Valve:	Free Valve or Replace Sub-Assembly or Complete Turbine Housing
Actuator / Wastegate Set Incorrectly:	Contact OEM or Turbo Specialist for Correct Settings

Engine Lacks Power

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Air Outlet Duct from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Restricted Inlet Manifold:	Refer to OEM’s Manual and Remove Restriction
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak in Air Supply from Air Cleaner to Compressor:	Replace Seals, Gaskets or Tighten Fasteners as Required
Foreign Object in Exhaust Manifold (from engine):	Refer to OEM’s Manual and Remove Obstruction
Restricted Exhaust System (back-pressure):	Remove Restriction or Replace Damaged Parts as Required
Exhaust Manifold Cracked, Gaskets Blown or Missing:	Refer to OEM’s Manual and Replace Gaskets or Damaged Parts as Required
Exhaust Gas leak at Turbine Inlet / Exhaust Manifold Joint:	Replace Gasket or Tighten Fasteners as Required / Check Surfaces are Square
Fuel Injection Pump or Fuel Injectors Incorrectly Set:	Refer to OEM’s’s Manual and Replace or Adjust Faulty Components
Air / Fuel Ratio Incorrect:	Check AFR and Correct Cause
Ignition or Engine Vlave Timing Incorrect:	Refer OEM’s Manual, Adjust Timing(s) as Required
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Actuator / Wastegate Set Incorrectly:	Contact OEM or Turbo Specialist for Correct Settings
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger

Smoke

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Exhaust Manifold Cracked, Gaskets Blown or Missing:	Refer to OEM’s Manual and Replace Gaskets or Damaged Parts as Required
Exhaust Gas leak at Turbine Inlet / Exhaust Manifold Joint:	Replace Gasket or Tighten Fasteners as Required / Check Surfaces are Square
Fuel Injection Pump or Fuel Injectors Incorrectly Set:	Refer to OEM’s’s Manual and Replace or Adjust Faulty Components
Air / Fuel Ratio Incorrect:	Check AFR and Correct Cause
Actuator / Wastegate Set Incorrectly:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger

BLACK EXHAUST SMOKE (black indicates fuel)

BLACK EXHAUST SMOKE (black indicates fuel)

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Restricted Air Outlet Duct from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as required
Restricted Inlet Manifold:	Refer to OEM’s Manual and Remove Restriction
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Foreign Object in Exhaust Manifold (from engine):	Refer to OEM’s Manual and Remove Obstruction
Restricted Exhaust System (back-pressure):	Remove Restriction or Replace Damaged Parts as Required
Exhaust Gas leak at Turbine Inlet / Exhaust Manifold Joint:	Replace Gasket or Tighten Fasteners as Required / Check Surfaces are Square
Fuel Injection Pump or Fuel Injectors Incorrectly Set:	Refer to OEM’s’s Manual and Replace or Adjust Faulty Components as Required
Air / Fuel Ratio Incorrect:	Check AFR and Correct Cause
Ignition or Engine Vlave Timing Incorrect:	Refer OEM’s Manual, Adjust Timing(s) as Required
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger as Required

BLUE EXHAUST SMOKE (blue indicates oil)

BLUE EXHAUST SMOKE (blue indicates oil)

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Foreign Object in Exhaust Manifold (from engine):	Refer to OEM’s Manual and Remove Obstruction
Restricted Turbocharger Oil Drain:	Remove Restriction or Replace Damaged Parts as Required
Restricted Engine Crankcase Breather:	Refer to OEM’s Manual, Clear Restriction
Turbocharger Bearing Housing Sludged or Coked:	Change Engine Oil and Oil Filter, Overhaul or Replace Turbocharger
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed

High Oil Consumption

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Foreign Object in Exhaust Manifold (from engine):	Refer to OEM’s Manual and Remove Obstruction
Restricted Turbocharger Oil Drain:	Remove Restriction or Replace Damaged Parts as Required
Restricted Engine Crankcase Breather:	Refer to OEM’s Manual, Clear Restriction
Turbocharger Bearing Housing Sludged or Coked:	Change Engine Oil and Oil Filter, Overhaul or Replace Turbocharger
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger

Turbocharger Noisy

Restricted Air Outlet Duct from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as required
Restricted Inlet Manifold:	Refer to OEM’s Manual and Remove Restriction
Air Leak in Air Supply from Air Cleaner to Compressor:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak in Air Supply from Compressor to Inlet Manifold:	Replace Seals, Gaskets or Tighten Fasteners as Required
Air Leak Between Inlet Manifold and Engine:	Replace Seals, Gaskets or Tighten Fasteners as Required
Exhaust Manifold Cracked, Gaskets Blown or Missing:	Refer to OEM’s Manual and Replace Gaskets or Damaged Parts as Required
Exhaust Gas leak at Turbine Inlet / Exhaust Manifold Joint:	Replace Gasket or Tighten Fasteners as Required / Check Surfaces are Square
Exhaust Gas Leak in Tubing after Turbine Outlet:	Refer to OEM’s Manual and Repair Leak
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger
Leaking Actuator Hose:	Replace Hose and Clips
Actuator / Wastegate Set Incorrectly:	Contact OEM or Turbo Specialist for Correct Settings

Cyclic Sound From Turbocharger

Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed

OIL LEAKING FROM COMPRESSOR SIDE OF TURBOCHARGER

OIL LEAKING FROM COMPRESSOR SIDE OF TURBOCHARGER

Dirty Air Filter(s):	Clean or Replace Filter(s) according to OEM Recommendations
Restricted Compressor Air Inlet Duct:	Remove Restriction or Replace Damaged Parts as Required
Foreign Object in Exhaust Manifold (from engine):	Refer to OEM’s Manual and Remove Obstruction
Restricted Exhaust System (back-pressure):	Refer OEM’s Manual Replace Gaskets or Tighten Fasteners as Required
Restricted Turbocharger Oil Drain:	Remove Restriction or Replace Damaged Parts as Required
Restricted Engine Crankcase Breather:	Refer to OEM’s Manual, Clear Restriction
Turbocharger Bearing Housing Sludged or Coked:	Change Engine Oil and Oil Filter, Overhaul or Replace Turbocharger
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger

OIL LEAKING FROM TURBINE SIDE OF TURBOCHARGER

OIL LEAKING FROM TURBINE SIDE OF TURBOCHARGER

Restricted Turbocharger Oil Drain:	Remove Restriction or Replace Damaged Parts as Required
Restricted Engine Crankcase Breather:	Refer to OEM’s Manual, Clear Restriction
Turbocharger Bearing Housing Sludged or Coked:	Change Engine Oil and Oil Filter, Overhaul or Replace Turbocharger
Worn Engine Piston Rings, Bores or Liners:	Refer OEM’s Manual and Repair as Required
Burnt Valves and/or Pistons:	Refer OEM’s Manual and Repair as Required
Excessive Dirt Build-Up on Impeller and/or Diffuser Vanes:	Refer OEM’s Turbo Manual and clean as directed
Turbocharger Damaged:	Diagnose/Correct Cause of Failure, Repair or Replace Turbocharger