OK this is a bit of a weird one, I have a pretty much stock (engine wise) V7 sti.
relatively regularly I will be cruising along the motorway and I will start to get a strange fluttering sound from the turbo area (sounds like its coming from right in front of the driver) this can vary from quiet to quite loud and goes up and down in rhythm with the boost level turning into a whine at high boost levels, during this I notice no loss of power or performance.
The weird thing is it isn\'t constant, some days I can drive around happily with no noise, other days it starts up pretty much as soon as the engine is warm. Initially I was thinking boost solenoid but the ebc screen shows no solenoid duty at the time the noise starts. Boost is built and held pretty much as it should.
I had the car in at speedtech for a warrant and during this time they took it for multiple test drives without the noise occurring once, I picked it up this afternoon and the noise started as soon as I hit the motorway, I turned around to head back and the noise stopped shortly before I arrived back at the workshop...
Does anyone have any idea what could cause such an intermittent noise?