Date registered: Dec 2005
Vehicle: 222.132 & 221.122 & 212.025 & 906.633
Mentioned: 3 Post(s)
Quoted: 32 Post(s)
OK, you are more familiar with the engine anyway than I thought. This is an I4 engine and the turbo I guess is not as close to the fire wall as in the V6, I would expect a bit less turbo sound to the cabin.
But I really cannot figure out how the air vents would be connected. Should not be voltage gain at higher engine RPM, there would be enough power to run the heater blower even at idle.
If there is a bigger leak, you should get fault codes but if there already has been some intercooler or intercooler pipe rework, I assume you already have tried to have a look at those. Although it isn't easy to gain turbo pressure more than momentarily when the engine is not loaded.
Would you have any opportunity to try another similar car to compare?