GSK

Well after replacing the MAF and the air temperature sensor my mechanic finally (he thinks) has figured out what the problem is with my experiencing loss of boost. After three hours checking all the hoses for air leaks and finding nothing we went out for a drive, he had a diagnostic computer attached to the car, I drove up to about 60 then floored it, the car accelerated and then the turbo ran 'flat', his computer confirmed that the turbo was not producing enough pressure. He then took the rubber hose off the top of the wastegate when we got back to the shop. He used a pressure gun to force air into the wastegate, when he pumped in the air the gauge on the gun showed an increase in pressure but as soon as he stopped pumping the pressure would fall, he thinks that the wastegate is not holding closed as it should. His diagnosis is that when I floor it that pressure builds up but the wastegate leaking air before it should causes a pressure loss in the system, the air pressure sensor then tells the ECU that there is a pressure loss and the computer goes into a limp home mode. When I switch off the ignition the ECU resets and it thinks everything is ok because switching off causes the wastegate to close again, whenever the pressure increases again the cycle starts over. He says he wants the car for a day to strip the system down and confirm before a new wastegate is fitted. Question: does all this sound feasible or could there be another reason for the system losing pressure??

QCRAZY

......what was it??

You most likely have a pressure deviation code, but don't know which one.

I don't like the story. A wastegate leaking pressure from the input signal would cause the car to over-boost rather than under boost. The wastegate itself shouldn't "creep" open because a spring counter holds it while it waits for boost pressure to tell it otherwise.

Not enough info given to offer much else.

Kimchee

torn tbb?

paulroad

Maximum Charge Pressure Exceeded.. is the code.

QCRAZY

Where was that posted??