I purchased some cool brushed aluminum tire valve caps to match my wheels and then I read this on the website:
TPMS sensors transmit tire inflation pressure to an electronic control unit to warn drivers when they have significantly low inflation pressure in one or more tires. These sensors can be damaged by dirt and water, so valve stem caps should remain in place at all times. TPMS valve stem caps are equipped with a small, internal o-ring to seal out dirt and water. If a sensor is left uncapped, it can lead to corrosion or other damage, requiring sensor replacement. Do not use metal caps. Sensors are made from a specific alloy, and the use of a metal cap made from a dissimilar metal can cause "galvanic" corrosion. This makes it hard to remove the cap and may cause the stem to break if the cap is forced trying to remove it.
WHAT IS THE CONCENSUS HERE ??

 

Meh. My TPMS sensors on the Ralliart started to have dead batteries at three years. I doubt you'll have enough corrosion issues before the sensors die to make a difference. If you're really worried, you can put a tiny bit of anti-seize on the valve stems to keep everything from binding up. It's cheap insurance.

 

It's true.


I had the metal caps and the corrosion eventually caused each TPMS to leak at the stem.


I did finally find a stem replacement kit (which saved the $130 each of a new TPMS including re-coding at the dealership).

 

I was using Aluminum ($3 off eBay) caps and didn't have any issues driving around salt drenched MoCo. Could be the chrome and steel caps that cause issues?

 

metal caps on tmps sensors usually cause problems with corrision as stated, but also as stated a little anti sieze will definately help with this problem, this info comes from 15 years in the auto industry and seeing way too many customers who put fancy caps on and then have issues, i have snapped many caps off because the customer refused to admit there was a problem.

 

We have seen this many times in our South Bend retail bay. Happened to one of my cars actually and it cost me a new sensor.

 

I had 2metal caps (not sure the alloy) become so oxidized that I broke the stem off. This is after a long hard NY winter with lots of salt on the roads. Only plastic for me from now on for my DD. When I do get an evo and store it in the winter, I would probably use them again.

 

The best caps to use are the caps that come in the TPMS "rebuild" kits, they're plastic and they have an o-ring to keep moisture away from the valve core. Its common practice to change the valve core as well as the grommet when replacing tires, and its common to see the valve core get stuck or break if people just use a regular plastic valve cap..

 

I am the 2nd owner of mine and the previous owner put the metal caps on with the Mitsu log on them looked nice but they never took them off. Now after 3 years they are seized. Had to replace one already, with the BBS wheels off been soaking them trying to avoid replacing them all.

 

They will seize on the valve stem, but a dab of antiseize before you put them on will do wonders. BUT, the mess and stickiness... so decide for yourself if it's worth it.

Also, if you do track days, the metal ones get hot. Kind of a pain when you are checking tire pressures after each session.