Valve stem caps are vibrating off
 

Hello,

My P5 is less than a year old. The first time I ever checked my tire pressure I noticed the tire valve caps were missing. I figured that the dealer forgot to put them on when I bought it. I replaced them.

A month later I discovered they were gone. First I thought someone was pranking me, so I decided to look for them every time I got in and out of the car. Weeks went by, nothing happened, I got lazy and stopped checking. Next time I went for air, they were gone again.

So then I set up a schedule of gradually spacing out my checks to see if they were loosening over time. Sure enough, they were doing just that. The front ones would loosen in two - three days tops, even after I finger-tightened them as much as possible.

Now I haven't lost any air pressure, but I'm still concerned that the extremely lousy Philly streets / minefields I drive over everyday somehow create just the right resonant vibration to loosen parts in my car! Am I crazy? I also hear a rattling sound from the frame of the car (can't pinpoint), which sounds like teeth or dice rattling.

Is there any chance that some parts of my car could gradually come apart from pothole resonance? Sorry if this is an inane idea, but thanks in advance for any help.

brahms117

I suppose someone could be playing mindgames with me, but that's a pretty lame mindgame! If someone were actually loosening my caps gradually every day, and doing *absolutely nothing* else to me or my car, I think would have to beat that person.

With all the pre-paving road stripping going on around me, it's like I drive over 10 miles of gravelly rumble strips every day. So it is sort of a sustained rumble, not just an occasional pothole.

But what about the other rattling sounds? It sounds like teeth, whenever I drive over a rough area. But it seems to come from the frame of the car. Could some screws be coming loose? Or are they just in my head..

brahms117

Is it possible that the valve stem threads themselves are a bit damaged? Hey, it seems unlikely, but you never know, you could have a bit of a factory freak :eek: ... also, put a video camera by your car... just kidding ;)

Sounds awfully odd to me, I have never heard of that happening (i.e. caps rattling loose). I will admit that I do not check my tires air pressure ofter enough, but when I do the caps are always still nice a snug (been the same way on any card I have had over the last ~15 years).

If you do think that it is the cap rattling loose on them might I suggest a little bit of the plumber's best friend in there... some teflon tape around the threads should make the cap sit a little tighter and can be cleaned off pretty easily if you need to get it out of there.

Is it possible you over-tightened the valve caps & stripped the threads? They are just plastic, after all. (or is that just on my "lowly" DX, and the rest of you get metal caps?;) )

Thanks everyone for your thoughts. I only use my fingers to tighten the caps, so I don't think I'm stripping the threads. I'm still baffled by this mystery. I could understand if one of the tires had a defect, but all four? I've only used the cheap plastic sets you find at Target / Walmart, even tried the chrome / plastic ones which could be wrench-tightened as well.

I'll try the teflon tape. Otherwise, I'll just have to keep changing them. But I'll let you all know when something larger rattles off. Like the passenger door or the roof rack.

brahms117

The underpant gnomes started a new business...

Tire valve caps --> ??? --> PROFIT!!!

:D

if its that big of a deal get some metal caps and threadlock