Hiya, i'm new to Audi forums but am hoping to find some answers to some of the niggles i've got with my A3 2.0 Tdi that i've owned since Dec 2010.
The 1st one is that around about 3 months ago the cars turbo started making a strange noise under acceleration between 2000-3000 rpm which can only be described as sounding like a brake squeel noise. The car still pulls well and it only does this when the engine has been driven for 20 minutes or more and is upto operating temperature. I just had a full service done at my Local Audi Dealer recently and they couldn't find no faults with the car. Also if you rev the car at a stand still it doesn't squeel either, only when the engine is underload and hot.
The 2nd one is that recently i've noticed the coolent level has started to drop nothing drastic though. I do around 600 miles a month at the moment and during that time the level goes from max to below the min mark. The car never overheats the temp gauge has never gone past the 90 oC/ half way mark, there is no sludge or water in with the oil or oil in with the water, the car drives totally fine.
I did how ever top the water up today with the engine running and cap off the expansion bottle and noticed lots of little bubbles coming up in the coolent which are only there when the engine is running. Could my Head Gasket and Turbo be on their way out.
Car has 88k on it and has always been properly serviced on the Longlife Schedule

Any advice would be much appreciated on the cause of either of these problems.

 

Got the car booked in on Thursday for a diagnosis but the garage boss reckons it needs a head gasket due to the bubbles in the expansion bottle whilst the car is running.