recently I found out that my 2.0TDI runs quite strange on idle. normally I had about 800rpm, but then it rises to about 950-1000rpm without any input/reason. after doing a couple of miles it returns back to 800rpm, then it rises back to 1000 (or time to time it keeps going 1000)..I thought it's because of A/C, but first it didn't do it before, and then it does the same whether the A/C is on or off.. any advice on that?
I plugged VAG-COM and it doesn't return any fault. One thing I remember, that before it started to do this strange things I had the battery disconnected for about 10mins (unintentionally). thnx.