Cruise control, valve shaft seals, hydraulic system

Hello everybody,

This is my first posting here in the forum, although I have been reading for months now. For a week now I have my long-awaited car, an Audi V8 4.2l BJ91 with unfortunately already 350tkm, but in itself good condition.

He survived the first 400km (transition Vienna->Tirol, Austria) absolutely smoothly. But in the meantime some shortcomings (and already known ones) have become apparent, perhaps one of you can help me to do so.

From the very beginning, the onboard computer informs me that one of the (according to the manual front) brake pads is ready. Lt. However, these are new sellers, which is also confirmed by my mechanic. So I guess a sensor problem - is this conceivable? Where would you start?

Two days ago, the on-board computer came up with a hydraulic problem. Too little hydraulic oil was in the container. I have now refilled this (was only 1/4 in) to 3/4 (that's all I had to hand). It seems to me that it will remain the same, but after every longer stop of the car find a small (hydraulik ?) oil pool under the engine. More closely, I noticed that the V8 must have been set up, as the underbody is damaged - and therefore I also have the oil that accumulates there. But now it is also the case that I find no oil at the oil measuring rod of the engine (although it is after-filled), but the computer does not indicate any engine oil loss (had to report for a long time?). I also feel that the oil salmon come from hydraulic oil, but not from engine oil. Can both the oil tank have a (small) leak as well as the hydraulic circuit a leak? Can the oil level sensor be defective from the engine?

I was told by the defector that the valve shaft seals were for exchange. I have a rather restless stationary gas and a kind of slag deposit here and there in the exhaust (which then spoils my garage floor, but doesn't matter), this can both come from the seals to be changed (Mechaniker means already). Also yesterday I found a very strong fibrizing of the vehicle when climbing up the mountain, which disappeared shortly afterwards. Can this also be a consequence ? Or it would be conceivable that one of the cynd candles spins and therefore a cylinder failed (for me, the old Audi 80 has already passed). I felt that the performance was slightly down.

It is also worrying to me that when the vehicle is parked (but little) very shallow smoke comes from the engine, like exhaust gases. But the exhaust system seems to be at first glance. I guess evaporating oil/hydraulic oil, can I be right with it ?

Then the cruise control does not respond, i.e. the cruise control cannot be set. This is the least evil, but it is annoying. Where am I supposed to start looking at the electronics themselves or at the mechanics of the lever?

Last but not least, the airbag control leak in the fittings is permanently lit. I'm assuming the fuse isn't OK. can this be ? Where would there be a mistake (from your experience) to accept here?

I hope that I have not formulated my many questions too vaguely, but I have practically no experience of these problems. In advance, I have to say that we will start working from Monday anyway (in the workshop), problem to eliminate problem and repair the damaged parts. We also have a Porsche center and a little further a Bosch electronics center, which we already used for several electronic problems. I just wanted to ask you for advice before, as you may have experience with the symptoms described and as such not looking for the wrong corner for days.

I thank you very much for any hints in advance and would like to thank you very much for the great site and forum! Without it I would not have my car (or with many more defects ...).

Best regards

Bastian