IDENTIFYING A TURBO FAULT
Noise, loss of power, smoke, fuel consumption d'oil or mode' dFaulty? Find out the main possible causes before replacing your turbocharger.
A turbo failure is not always caused by the turbocharger itself. A lubrication problem, d'admission' d'air, dProblems with the exhaust system, engine ventilation, variable geometry or control systems can cause the same symptoms.
1. Turbocharger inspection
After dWhen removing the pipe connecting the air filter to the turbocharger, carefully check the rotor play.
If the radial play is sufficiently large for allowing the wheels to touch the casing; the turbocharger is wearing out excessively.
2. Turbo unusual noise or whistling sound
Possible causes:
- Air filter or intake d'stuffy air'.
- Conduit d'blocked inlet'.
- Contaminated or damaged compressor wheel.
- Leak d'air between the air filter and the turbo'.
- Leak between the turbo and the manifold d'admission'.
- Leak at the manifold d'admission'.
- Gas leak d'exhaust before or after the turbo'.
Check the hoses, clamps and pipes d'intake, air filter, manifolds and fittings' d'exhaust' before concluding that a dTurbo failure.
3. Consumption d'excessive oil'
Possible causes:
- Admission d'stuffy air'.
- Return pipe d'clogged oil'.
- Turbo bearing housing clogged or carbonised.
- Contaminated compressor wheel.
- Leak on the circuit d'admission'.
- Poor ventilation of the engine sump.
- Worn piston rings or cylinder liners.
- General engine wear and tear.
Poor oil drainage from the turbocharger can cause pressure to build up in the central housing and result in the passage of d'oil on the compressor side or the turbine side'.
4. Loss of engine power
The main points to check:
- Air filter and ducts d'admission'.
- Hoses between the turbo, intercooler and manifold d'admission'.
- Intercooler blocked, punctured or dDefective.
- Leak in the turbocharger circuit.
- Leak on the manifold d'exhaust'.
- Catalyst or line d'blocked exhaust'.
- Pipes for dDamaged turbocharger intake pipes.
- Wastegate or valve dDischarge dIneffective.
- Variable geometry system seized up or clogged.
- Boost pressure sensor dDefective.
- DFlow meter d'air' dDefective.
- Clogged EGR valve.
- Problem d'fuel injection or engine wear'.
A loss of power does not, therefore, automatically mean that the turbocharger is out of action.
5. Leak d'oil on the compressor side'
Possible causes:
- Admission d'obstructed or severely restricted airflow'.
- Back d'oil from the blocked turbo'.
- Central housing clogged or carbonised.
- Major leak in the circuit d'admission'.
- Poor ventilation of the engine sump.
- Excessive pressure in the engine sump.
- Engine wear and tear.
The presence d'Oil in the intake system does not therefore necessarily mean that the turbocharger seals are dDefective.
6. Leak d'turbine-side oil'
In particular, check the following:
- The return pipe d'oil'.
- The condition of the bearing housing.
- Engine sump ventilation.
- Internal engine pressure.
- The condition of the segments and cylinders.
A leak d'Oil on the turbine side may cause the oil to burn on contact with the gases' dThe exhaust system and cause blue smoke to appear.
7. Blue smoke from the exhaust
Blue smoke usually indicates the presence of d'oil burnt by the engine or in the system' d'exhaust'.
Possible causes:
- Admission d'stuffy air'.
- Back d'oil from the blocked turbo'.
- Charred bearing housing.
- Leak d'air in the turbocharger circuit'.
- Poor ventilation of the engine sump.
- Wear on the piston rings or cylinders.
- Engine wear and tear.
A significant amount d'Oil in the intake system can pose a serious risk' for the engine. Have the vehicle checked before continuing your journey.
8. Black smoke from the exhaust
Black smoke may appear when the amount d'There is insufficient air available relative to the amount of fuel injected'.
Possible causes:
- Clogged air filter or air intake.
- A punctured boost hose or dDislocated.
- Intercooler dDefective.
- Manifold d'clogged intake'.
- Gas leak d'the exhaust pipe before the turbo'.
- Catalytic converter or blocked exhaust.
- Contaminated or damaged compressor wheel.
- Problem d'injection'.
- Engine wear and tear.
9. Motor in mode dDemoted
A switch to dPower loss may be caused by boost pressure that is too low or too high.
To be checked:
- Clogged or seized variable geometry.
- Variable-geometry control ring.
- Boost pressure sensor.
- Pneumatic or electronic turbo control.
- Injectors or system d'injection'.
If the dIf the fault disappears after switching the engine off and then restarting it, but then reoccurs, the problem must be diagnosed: restarting the engine does not eliminate the cause of the fault.
10. Loss of power at high revs
- Pressure sensor dDefective.
- DFlow meter d'contaminated air or' dDefective.
- Clogged EGR valve.
- Catalytic converter or blocked exhaust.
- Problem d'injection'.
11. Power loss when the engine is hot
- Conduct of dDamaged turbocharger housing.
- Catalytic converter blocked.
- Fuel pump or system d'injection' dDefective.
12. Excessive turbo pressure
Main causes:
- Variable geometry blocked by soot.
- Seized variable-geometry control ring.
- Wastegate or valve dOutlet stuck in the closed position.
- DFault in the turbocharger control system.
Excessive pressure may cause the engine to switch to dDeteriorate and, if left unchecked, damage the turbocharger or d'other engine components'.
When a turbocharger is damaged, it is essential d'to identify and rectify the cause before fitting the new turbo'. Otherwise, the new turbocharger may quickly suffer the same damage.
NEED D'HELP' For HOW TO IDENTIFY YOUR TURBO ?
Please have your turbo part number or your vehicle details to hand. The ALFI TURBO team can help you identify the right product code.
CONTACT ALFI TURBO