Hello, I'm new to the Audi forum, and am looking for advice on the beginning of a corrosion problem on my '02 S8. There are a number of very small locations where corrosion is starting, which i believe is due to steel pieces being in contact with the aluminium body panels.
has anyone encountered similar problems, and if so, any suggestions?

 

First off I must say hello to my northern neighbour. If you ever take a trip down to Vancouver you should come over to some of the Vancouver Audi Club meets. Second I must say I love your ride, as I've always craved to own an S8! Finally, as far as I know your vehicle has an all aluminum spaceframe so there really shouldn't be any corrosion at all, and there are no steel body panels. There are certain parts that may be made out of steel, such as the hinges and such but I've never really heard of accelerated corrosion on an A8/S8 model. Do they use a lot of salt up there? Perhaps those are salt spots. Any possibility of taking pics?

 

Hello Southern Neighbour. Thanks very much for your reply. The S8 does have an entirely aluminium space frame, and I believe that all body panels are also made of aluminium. So, yes, there should be no rust on these models whatsoever. Aluminium doesn't "rust". What I believe is happening, is galvanic corrosion at points where steel fasteners have been used (bolts, rivets, etc.) that are in contact with the aluminium. The corrosion spots are starting in pinpoint areas that look like there is a fastener beneath. The chrome trim has spots starting in exact positions which are approximately 6" apart; at the points of the metal clips that retain the trim. I don't have any pictures at the moment, but will take some later this week. I contacted Audi Canada, and of course, no response. I'm simply looking for advice on how to stop this, but I'm sure that their customer relations department view it as a possible claim. I am looking at one of the electronic rust inhibitors; such as the counterAct unit. Has anyone had experience with these?
Yes, the S8 is a fabulous machine!

 

Yes, your car is fantastic! It weighs a good 300lbs less than mine and has 160HP more than mine. On top of that it is roomier for rear passengers. I will own one some day!

I don't have personal experience with the CounterAct electronic rust inhibitor that you see at Canadian Tire but from what I gathered from other people who do operate their vehicles with this is that you have to install these before rust actually begins.

I can tell you that you will never get any response from Audi of Canada. The after-sales support from Audi of Canada for vehicles older than 1 year is pretty much non-existent. I hate to say it but that is the truth. Many of us have discovered this the hard way.

I would recommend carefully removing the trim pieces that show signs of surface corrosion and cleaning them off very well. Then applying a corrosion inhibitor.

 

very unfortunate that Audi Canada have no ears for their customers.
I did contact CounterAct directly to ask the specific question about the aluminium galvanic corrosion, and of course they said that their device is applicable for this problem. They also sent me a testimonial letter from a manufacturer of boat trailers that use the CounterAct exclusively on their aluminium/galvanized trailers. From what I learned, this electronic inhibitor will stop the further corrosion process. Definitely worth a try, since there doesn't appear to be any other option to address this.

 

Yeah, I'm done dealing with Audi of Canada. I'm done dealing with OpenRoad Audi or any Audi dealership, really. They see me pull up in my A4 or A6 and they treat me like I'm poor because I don't drive the newest or latest A8 or S4.

I'd recommend trying to clean off any signs of corrosion with either a scrubbing pad or gently with some synthetic wool and then using rust inhibitor spray. I wouldn't recommend installing the CounterAct system until the existing corrosion has been treated.

Hope things work out well for you. If you ever come down to Vancouver let me know and we'll go for a ride with the rest of the Vancouver Audi Club. Mainly A4 guys but I'm the only one so far with a A6. We have yet to have an A8/S8 come by.

 

Have been following this thread and its outcome. Posting up some detailed pics of the problem would help. Thanks

 

Wow, I thought I was the only one following this thread!

 

I'm following too! Only corrosion I have is on the actual steel bolts/hinges etc that are used in certain places, like hood mounts. Aluminum has not yet started to corrode. It can oxidize and then eventually crumble. It doesn't corrode or "rust" out like steel. No red stuff (iron oxide). It will eventually weaken and destroy the Al. There's very little in way of repair for Al parts. Body filler and paint I suppose. You'll need to isolate the steel components from the Al components with gaskets, o-rings, washers (fibrous) and /or coatings. That should work as well or better than the galvanic protection system you're thinking about. You'll have to have a steady and moderately powerful electrical supply to protect entire car. These systems can drain battery if car is left for too long, so be careful. If you use it, let us know how it works out.