1. Loss of power and flat spots
The car accelerates sluggishly, especially uphill and when overtaking. This is the most common sign: the turbo is not delivering enough boost.
2. Blue or grey smoke
Bluish smoke usually means oil is burning. Worn turbo seals are a frequent cause.
3. Black smoke
Black smoke means the engine is short of air. The cause can be the turbo, its geometry or a cracked intake pipe.
4. Whistling or whining
A new, loud whistle that rises with rpm often means shaft play or a wheel rubbing the housing.
5. Higher oil consumption
If you keep topping up oil and there are no leaks, check the turbo: oil may be going into the intake or exhaust.
6. Oil in the intercooler and hoses
Oily hoses after the compressor are a classic sign of worn turbo seals or bearings.
7. P0299, P0234 codes and limp mode
P0299 means underboost, P0234 overboost. They are often caused by the VGT geometry or actuator, and calibration fixes the problem without replacing the turbo.
What to do
Do not keep driving for long. If the wheel breaks up, fragments can enter the engine, and a diesel can run away on its own oil. Bring the turbo in for free diagnostics — it almost always costs less than an engine repair later.
Bring it in for free diagnostics. You get the exact price before any work starts.