bobo d

Hi everyone,
I have a question about losing coolant fluid. We have a A8L and a S8, both 2003 (D2). Both cars are around 120000 km and both cars are driven in city traffic between 10 km and 20 km a day. My wife's A8L never goes above 3000 rpm. Both cars operate at a temperature around 90 C. I notice pink disposal around the expansion tank cap of both cars. I don't see any other coolant leaks in the cars. I am wondering whether the caps may be defective or broken or whether there is something else like broken T-stats or whether this is something common for these vehicles. We have had the cars for 3 years and I have been noticing losing about 1 l of coolant fluid every 3 months. Any help is much appreciated.
JD

silverd2

I've had problems with the cap on my reservoir...very slow leak over time. I replaced it with a new one and found that I still had to screw it on tighter than you'd think to maintain a seal. Part of the problem seems to be with the rim of the plastic tank being slightly irregular with age and not sealing as well as new. So tighter does it for now.
Love my car, but the cap design is antique & outdated compared to the type caps used on VW's...even older ones than my D2.

Perpetual Novice

I've had the same issue, replaced the cap, and now the new cap is on its way out as well.

Out of curiosity bobo, when you top it up are you topping up with 50/50 of the right coolant?