:confused2:

The other day a tire fault came on the MFI. I went to check the tire pressure and the chrome valve stem caps, which I had since day 1, were all seized onto the valve stem. I was able to get one off, the other one cracked the whole valve stem when I torqued it. It seems as if the valve stems corroded.
I have a service appointment on 7-17-06. I'll let you know what they say.
I have the same caps on my 2002 A6. Never any problems.

Standard caps from VW for the TPMS stems are plastic so as to avoid this problem.

Sounds like you had some aftermarket metal caps, eh?

 

If you have TPMS you must use plastic or alum. caps. Steel caps on the alum. stems will corrode rather quickly. The same with valve cores, they must be nickle plated or they will corode also.

 

I have a plastic looking valve cap cover and it’s stuck on 1 tire. It’s becoming an issue now with such cold weather -21 degrees Celsius!! Does anyone know what would cause a plastic stem valve cap cover to be stuck on?

 

The first Winter after I bought my used Treg I ran into this issue. All I did was I used a pair of pliers to hold the valve stem from moving while I used another pair of pliers to turn the cap until it broke loose. I replaced all the caps with new aluminum VW logo short caps and regularly take them off to make sure they aren't stuck.

 

I regularly take my caps off every couple of weeks to check tyre pressures.

Bonus, it stops them seizing up.

 

Despite having TPMS on my Touareg, I have a set of aftermarket valve cap TPMS sensors for my caravan (travel trailer) which have brass fittings - I used them on my Touareg for a short while to check the instantaneous pressure/temperature but they caused corrosion due to the interaction between the brass and the alloy valve stem

 

Vaseline.