Hello dear tolker, I drive an audi 80 convertible 2.3 liters NG automatic and have found the following problem, for about 4 days I noticed that I have oil in the balance tank (light brown) and we simply can not explain where it comes from. They were made about 1 year ago, New cooler/oil cooler, which is such a cooler for the engine as well as for the transmission, for that I paid 380Euro, what was still done, cylinder head seal as well as timing belt pump and so, and we have already driven over 30000Km without problems, no power loss or otherwise what. Engine oil is clean, no white slipper or the like, gear oil is also clean, no problems, only where does this oil come from and how can I see what it is for oil whether engine or transmission?? Please help me, I start my training on 18.08 and have to drive a couple of km. and I need my car quite penetrating 🙁 Ps. I have searched in the sufu, unfortunately no answers found