2004 S4 Coolant Leak

[rj1983]

Hi all,

I've owned my S4 for about 3 months now and it has been relatively pain-free, save having to change a coil pack.

Unfortunately the coolant light has been coming on and despite topping up about 3 weeks ago it has dropped again.

I think, but am not entirely sure, I have seen mist coming up out of the bonnet which I can only assume is the coolant escaping from somewhere.

I read that sometimes it can be the cap which is nice and cheap to fix, but that it could be the rads.

Anyone had experience of this/ know estimated costs for fixing either scenario?

Cheers

[caiss4]

Auxilliary rads in the wings are prime candidates and known to suffer premature corrosion. I had one replaced on mine just outside of warranty but I kicked up a fuss and Audi UK 'generously' discounted the replacement to about £75 (at the time they were >£100). Local dealer eventually did the job for free but I seem to recall the labour charge was going to be about £300.

BTW, steam rising from the bonnet can be condensation evaporating first thing in the morning as the engine warms.

Edited by caiss4 on Monday 27th July 13:35

[Dr G]

Yes, almost certainly the aux rad(s) on an S4.