s13logan

We've always been big Audi fans - in fact we've had 4 Audis in the last 10 years. I've come across a number of S6 Avants with mileage between 100 - 150k. It has the same 4.2L my old A6 4.2 had (though mated to a 5-speed trans instead of the 6-speed I had), so I'm pretty sure based on my 7-year experience that they're fairly reliable. I just don't want to buy a headache since I'm leaving it somewhere that we hope to use to relax. Any suggestions on what to look for service-wise? How can I make sure it's a solid performer (to the best of my ability) for a few more years without major repairs? If it sits for 2 - 3 mos without being driven, will that be a problem? I get that some of these are general worries and nothing you can avoid 100% with a 15-year-old car. I just want to do all I can to mitigate future issues. Any advice/insight is appreciated!

tester123

Well, like you said, there is no 100%. With that, ensure the complete timing belt service has been completed (including water pump). Not sure if this has been updated but, there is a plastic pipe for coolant to Oil cooler which breaks and you get a slow coolant leak. The right way to fix it is to use the "bufkin" pipe. Search on it.

If you are going to leave it sitting, make sure you add some additive to gas tank to remove water (I think it's called HEET or something like that). Also, keep the battery on trickle charge. Make sure tires have no leaks and pressurized properly.

Also, it would help if the Transmission fluid is changed (with filter of course), and gear oils are changed. At 100k, they should be even though AUDI says they are "life time". Check all wheel bearings, CV boots, tires, brakes etc. and make sure they are in good condition. Top off all fluids (brake, oil, coolant, windshield washer - optional)...

Almost forgot, see if the "Flange shaft seal" needs to be replaced. On older models, it wears off and drips gear oil on the exhaust. The actual part is simple but repair is PIA because you have to drop the drive shaft to change it. This was modified / update on later years so, you have to dig up on that.

Lastly, keep it in a cool dry place so interior leather won't get molds etc. and if possible in garage or at least, a car cover to protect it from elements.

After that it's anyone's guess.

Mine is at 150k recently and I didn't think twice to drive long distance (1200+ miles round trip) last week because of the above said maintenance. If you pay attention to its "health" consistently, there is no reason to worry.

s13logan

Thank you VERY much for the quick reply!! Great advice! If you think of anything else, please let me know. I'll keep you posted on what we decide.