I own a 57 plate s3 with 15500 miles on it . About 2 months ago i noticed that the car didn't feel to be accelorating as normal and that there sounded to be a whering noise coming from the engine,i thought it could be the turbo, so took the car to my local dealer. When i went to pick the car up they told me that the turbo was fine, and that the problem was that the oil was at minimum and also it was the wrong oil. Now the only people to put oil in the engine was Audi , which i checked 2 days before it went in to the garage and it was in the middle of the dip stick so to be told that there was no oil in the engine was a concern. Now Audi filled the engine up with oil and told me to keep an eye on it and if it changed after six weeks bring the car back. I've been checking the oil regular since and it hasn't move from the top of the dip stick, but the car now feels the as before, the oil is very black and there is a shooty deposite on the tale pipes of the exhaust, the whering noise has also returned. Any ideas would be very heplful ?