I got my new 2006 A6 S-Line in late March. It is awesome. I would like to get some of those nice, red-logo Audi sport metal valve stem covers that are on the Audi USA Website. But ther eis this big warnng that says "Not To Be Used On Vehicles Equipped With Aluminum Valve Stems. Dissimilar Metals Can Cause Corrosion Under Certain Conditions". Simple enough.

What is NOT simple however is to figure out if, in fact, my vehicle is one of those equipped with aluminum valve stems. The threads on my valve stems is a very nice, clean matte silver color. So my stems potentially COULD be aluminum. So far I have done the following to try and figure this out:

a) Contacted Audi Customer Service. Result - No information at all, advised me to contact my service rep at the dealership.
b) Contacted my Dealership Service Rep. Result - No information. They asked the tech and the tech has no information either. Advised me to talk to someone at a tire store.
c) Talked to professional tire installer at a local tire shop. Result - "They could be aluminum, or stainless steel but there is no way to tell".

I asked Audi Customer Service about this again today, and they checked with a supervisor on their end, and the supervisor says "Anything sold on the Audi website is compatible with Audi vehicles". My response "Then why the need for a big disclaimer about Aluminum Valve Stems? If no Audi vehicles are equipped with these, then why go to great lengths to ensure this disclaimer is present of all of the valve stem products sold on the Audi website?". There response "That is a good question. It doesn't make sense does it? Well we don't have the information available. Sorry". Not that they are not trying their hardest to be helpful, they really are trying to be helpful, it is just that the information is not provided to them by Audi, so they are basically as out-of-luck as I am in terms of figuring this out.

I don't feel like taking my car in to a metalurgist to have lab tests done in order to confirm that my valve stems are or aren't aluminum ones. Is there anybody out there in the Audi Forums community that might have a clue about how to figure this out? I have a 2006 A6 4.2 S-Line with 18" rims and Michellin Low Profile Tires.

Any information would be appreciated!

 

Im not 100 percent sure here but i think they are talking about the valve stems for the tire pressure montitoring system. They are metal probably aluminum due to location. Your stems are rubber. Just put them on. Youll be fine. If your really worried about it checked them ocassional for corrosion.

 

Thanks for the reply dankhound. They are not talking about valve stems for the tire pressure monitoring system. They are talking about the valve stems that stick out of the rims, and that you use to fill the tires with air, and that the valve stem caps that are sold on the AudiUSA website screw onto.

More specifically, I am asking about the "threads" that the valve stem caps screw onto...and which would be in contact with the new metal valve stem caps that I want to purchase. These are definitely not rubber. Yes the part that sticks up from the rim is rubber, but the screw threads that the cap goes onto are a silver matte finish metal. Definitely metal. I am no expert but I do think I am capable of distinguishing metal from rubber

I prefer not to have to periodically check for corrosion. I'd like to install something that is compatible, and won't generate a problem in the first place. The problem with the "check for corrosion" method, is that, by the time you check, and there IS corrosion, it's too late. Corrosion is like cancer, once it is there, it is very hard to get rid of it, and you probably end up having to replace the valve stems. Something I prefer to avoid.

Thanks for looking into this in any case. Anyone else have a way to tell if the metal screw threads on top of my valve stems are aluminum or some other metal?

 

chrome mate, no problems with the alloy wheels you can also get chrome covers for the rubber part that sticks out from the wheel to prevent them being cut off ( the rubbers that is )

[IMG]local://upfiles/12092/B14C804CB48842A9A327D138A9106360.jpg[/IMG]

 

the type in the picture are not advisable because they leak after a while but look good

 

Well, a little more research and I have answered my own question. My valve stems ARE aluminum.

I talked with an Audi parts specialist at Rusnak Audi in Thousand Oaks today, and he informed me that if my car is equipped with a tire pressure monitoring system, which it is, then my valve stems are made out of aluminum.

That means that if I had taken the advice that the Audi USA folks gave me on the phone that "all of the products on their website are compatible with all vehicles" and put the chrome plated brass caps on my aluminim stems, they DEFINITELY would have caused corrosion (brass and aluminum placed in contact with each other will quickly generate corrosion of the aluminum) and ultimately, I would have had to have the aluminum valve stems, which each include a transmitter for the tire pressure monitoring system, replaced....probably at significant expense.

So there it is....if you have an Audi vehicle, and it has a tire pressure monitoring system, then you have aluminum valve stems, and you are asking for trouble if you put caps on them that are made from any metal other than aluminum. Plastic caps of course will work fine too. This same tech told me that Porsche uses the same tire pressure monitoring system, so if your other car is a Porsche, this same thing applies to you.

So I am now out to find some nice aluminum valve stem caps. Probably the red anodized ichibahn ones will look great on the car, and they are made from 100% aluminum so won't cause any corrosion problems.

 

So the tire pressure monitoring system actually reads the pressure in each tire?
I thought it just worked on different rotational speeds of each wheel when driving in a straight line.

I've seen those systems on hummers and such that will inflate/deflate a tire on the fly (deflate when you need to get more traction in slippery mud etc, inflate later)

 

If the part that sticks out of the rim is rubber then you dont the tire pressure monitoring stems. The tire pressure monitoring valvestems are all metal. No rubber whatsoever.