Plastic Tire Valve Caps
06-22-2018, 12:10 PM
#21
Le Mans Master
Here is the quick answer. Even though you guys know better, I'll post it anyway. 
Metal caps can easily cause corrosion on the threads of TPMS stems as well as beginning to corrode themselves. The result is all too often that the cap will rust-weld itself to the stem, leading to outcomes from the cap simply seizing when a technician tries to remove it, to cross threading issues, or even having the stem break off entirely. When the valve stem is a nonremovable part of the TPMS monitor, this goes from being a minor issue to a critical and often expensive problem.
Metal caps can easily cause corrosion on the threads of TPMS stems as well as beginning to corrode themselves. The result is all too often that the cap will rust-weld itself to the stem, leading to outcomes from the cap simply seizing when a technician tries to remove it, to cross threading issues, or even having the stem break off entirely. When the valve stem is a nonremovable part of the TPMS monitor, this goes from being a minor issue to a critical and often expensive problem.
Dave
06-22-2018, 12:31 PM
#22
Melting Slicks
Im from NJ (originally) and now in PA - so Im pretty north...and my cars see rain and snow...I've never had a cap seize on me...even the cars I didn't really maintain often... Not saying others might have had an issue, but I can clearly state I haven't.
06-22-2018, 02:05 PM
#23
Le Mans Master
Dave
06-22-2018, 03:46 PM
#24
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I’ve used the metal caps for many years on my car and have not had any problems with them sticking to the stem or interfering with the sensors.
06-22-2018, 04:33 PM
#25
Racer
I have very similar ones. With the Jake logo. Mainly because they have red accents that are a nice touch with my black wheels and red calipers. Super cheap and fun mod
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c54u (06-22-2018)
06-22-2018, 06:17 PM
#27
Melting Slicks
06-22-2018, 06:22 PM
#28
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Bill
06-22-2018, 07:43 PM
#29
Race Director
I thought the C7 sensors didn't need training with a magnet (or any special tool for that matter) like the C5 and C6? Don't they just learn on their own after being installed on the wheel and driven a few miles?
06-22-2018, 07:45 PM
#30
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My C5 has the original aluminum caps and though I've not checked today, they've worked fine for over 17 years! 
06-22-2018, 07:59 PM
#31
Le Mans Master
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Patman (06-23-2018)
06-23-2018, 07:35 AM
#33
Drifting
A quick google search for stuck tire valve cap will yield many instances of stuck corroded metal caps.
06-23-2018, 08:40 AM
#34
Race Director
06-23-2018, 12:30 PM
#35
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PatternDayTrader (06-23-2018)
06-23-2018, 12:56 PM
#36
Pro
Yes, my brother had to cut his stems off with a grinder after caps welded themselves. corrosion. Although it was on his daily driver so road salt may have been a factor too.
06-23-2018, 01:14 PM
#37
Race Director
Once in awhile you can get a pair of sharp side cuts (dykes) to grab the bottom edge of the cap and sort of twist them in a way that can peel the cap edge back, obviously this destroys the cap, but you can save the stem. Sometimes.
06-23-2018, 01:20 PM
#38
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On my previous BMW I had all 4 metal caps seize up on me and I was lucky to get them off with only minimally damaging the TPMS valve stems. Part of the problem was that I had a tendency to put them on too tightly.
As I remember on the C6 that came with metal caps, the recommendation was to use metal caps as they aided the strength of TPMS radio signal to the control unit. Nothing like that on the C7.
As I remember on the C6 that came with metal caps, the recommendation was to use metal caps as they aided the strength of TPMS radio signal to the control unit. Nothing like that on the C7.