USCRugby

Does anyone know a good place to order this? I personally would like to know where to get a college valve cap. My Univ of South Carolina Gamecocks to be specific!

jmcraney

I assume that you are talking about caps for the valves on the tires? If that is what you are talking about, you need to be cautious about replacing the valve caps. On some TPMSs the valve cap is part of the antenna for radiating the signals from the sensors in the tires. I have looked at the caps on my car and they seem to be specialized - metal, with a contact pin to the inner part of the valve. If someone has specific knowledge about this please correct me. You should also be aware that it is probably not a good idea to replace the caps with plastic ones as that might cause the TPMS to be unreliable.

USCRugby

hmmm excellent advice. I guess I won't be changing mine!

Dave Mac

I hope someone else adds to this thread about the concept of the metallic tire valve cap being being part of an antenna system for the TPMS on our Lexus. I replaced my valve caps with chrome metal caps within the first few hours and have never been impressed with the accuracy of the TPMS so would like to hear more. Several Lexus dealers promote the nitrogen fill for tires as an option and when they do that they put on colored plastic valve caps often blue or green I think.

I just went out an examined my OEM valve caps and can't see anything like a wire inside of them

I also read the description of the TPMS in my service manual and see no reference to the valve caps and I think they probably do nothing more than keep dirt out of the valve.

Again - this is intersting though and I hope to hear more.

Dave Mac

jmcraney

I remembered where I got that about the valve cap. It was relative to GM and Corvettes.

http://www.hunter.com/PUB/undercar/techlink/index.htm

This is what it says:

Quote
The valve stem cap is made of aluminum and the valve core is nickel-plated to resist corrosion. The end of the stem serves as the sensor’s antenna.

TIP: Do not replace either the cap or the valve with standard parts. This will interfere with the sensor’s ability to transmit.
End quote

This probably doesn't apply to Lexus although I see lots of cautions about corrosion with certain valve cores for after market replacements parts.

My caps are aluminum and I see lots of warnings on the Internet about dissimilar-metal corrosion issues if the aluminum caps are replaced with other types of metals.

Obviously there is no problem with plastic caps.

And my comment about a contact in my valve caps was also erroneous - old-eyesight problem.

My apologies for the confusion.

Johnny

JMc's assertion is correct. All the reading I've done on it support this fact.

Tirerack has a good write-up on this that has been plagiarized by quite a few websites.

Some other facets deal with the TPMS's calibration and the manufacturers that subscribe to Lexus's philosophy regarding the localization of the transmitters versus other system. There are some good reasons why Lexus went the way it did. Read up on it...