Join Date: Jan 2008
Location: United Kingdom
The turbo is OK as it is still boosting, but over boosting as you say. This could be because;
The waste gate actuator is duff - hole in the valve diaphragm. Replace actuator.
The valve diaphragm is stuck due to corrosion from water ingress - spray some WD40 into the back of the valve housing via the small vent hole - if you can access it
The vacuum hose connected to the waste gate actuator valve is split or detached - replace or reconnect
The wastegate actuator is a gold coloured canister, on the side of the turbo, with a rod coming out of it. The rod connects to the wastegate in the exhaust turbine. There will also be a black rubber hose connected to the canister that provides the vacuum.
Check out the above first...........someone else may come along and suggest other causes for investigation also.
If the turbo was blown, you'd have no boost and clouds of smoke from the exhaust.
Good luck and keep us posted.
PS - If the wastegate actuator is faulty, the turbo will probably need to be removed to gain access to it, they are normally fitted at the back of the turbo adjacent to the cylinder block so are not easily accessible. If the vacuum hose is connected and appears to be intact, take the car to a turbo specialist or local motorsport garage..........they are best placed to diagnose the fault.
Last edited by STU_V6; 04-08-09 at 19:30.
Reason: PS added