Mercedes-Benz W163 CDI boost pressure leaks and turbo noises
Mercedes-Benz W163 CDI smokes and lacks power, could a boost leak be the cause?
Yes. A crack in the boost hose between the turbo and the intercooler can cause heavy smoke and a lack of power. Typical leak points are cracks in the hose and the quick-release couplings of the intercooler.
Why does the Mercedes-Benz W163 boost hose quick coupling come off under acceleration?
The coupling may not have been pushed fully home, in which case the locking pin does not seat properly. When the coupling is pushed all the way in and the lock is fitted, the hose stays in place even under boost pressure.
Is a whine from a cold Mercedes-Benz W163 CDI turbo normal?
A low whine from a VNT turbo (variable geometry turbo) when cold is normal. The sound quietens as boost pressure starts to build and disappears after 1-2 km of driving. It is not a sign of a boost leak.
What does fault code P2027 mean on a Mercedes-Benz W163 400 CDI?
P2027 means a signal fault in the right-side boost pressure regulator. The fault may be on the turbo side. The regulator can be tested by borrowing a regulator from another car, and the turbo can be reached through the wheel arch.