Locktite on valve stem covers!!!
 

So, I decide to check the air pressure in my tires tonight. I can't get either of the back tire valve stem covers off, with mild finger pressure. These are the nice chromed ones, with the BMW roundel on the top (given to me as a gift by one of our wonderful fellow board members, BTW). I don't want to destroy them, but I have to get the darned things off. Finally, I put two sets of ViseGrips on there (one on the stem, one on the cap), and manage to remove the caps.

What do I find? The telltale evidence that someone put them on with Locktite!!! Those who have used it know what I am talking about--the fine white powder in the threads. I air up my tires, and put the caps back on with some oil.

I am sure I have checked my tire pressure since I got new tires a few months ago. And I can't believe a tire shop would have done that, anyway. Vandalism? :banghead:

That's a new one. Sorry to hear.

Odds are not vandalism but environmental... I see the pretty chrome metal valve caps get corroded on all the time, something about the two different metal surfaces contactinf causes corrosion. (just like aluminum and steel)

Good call with the oil on the threads to prevent it from happening again.

Good thought, but it didn't effect the front ones at all. Seems like it would be similar for all 4. :dunno:

Maybe the excessive brake dust on the fronts acted as a weather barrier. :rofl::rofl::rofl:

I've seen it plenty of times too. It's not loctite and it doesn't happen to all the valve stem caps. It from simple corrosion between the metal valve stem and the metal valve stem cap. That problem is one of the 2 reasons why BMW has now switched to ABS valve stem caps.

Now I have to ask----the other reason? ;)

Well since you asked! The TPMS BMW now uses across the entire model range has sensors in every wheel and all metal valve stems (not metal/rubber valve stems). Metal valve stem caps were interfering with the signals and so BMW includes only plastic (ABS) valve stem caps on these valve stems. In addition, to prevent owners from generating problems for themselves, the accessories catalogs now only carry valve stem caps in the BMW roundel, M logo, etc. styles made of ABS.

See attached representative photos:
1. ABS valve stem caps (BMW Roundel Logo - P/N 36-11-0-421-544)
2. Brass valve stem caps (BMW Roundel Logo - P/N 36-11-0-009-840)
3. Rubber valve stem (P/N 36-12-1-178-869)
4. Metal valve stem (with generic ABS cap) (P/N 36-11-1-096-449)