Sometimes tire valve doesn't shut after being pressed
 

The Schrader valve on one of my RX's wheels will sometimes not completely close after testing it with a tire gauge. Like I'll push the tire gauge onto the valve and take it off, and when it's taken off, once in like every three times, the valve doesn't close and air hisses out until I test it again.

This freaked me out. I figure the valve core might be busted.

I was going to take the air out and replace the valve core with something found in a bike shop (it's a standard Schrader valve after all), but thought I'd ask here as a sanity check.

I have the tool to replace a Schrader valve core, done it on bikes and ATV's but never on a car tire with TPMS sensor on it.

Can I just swap in the valve core with a different one? Any advice?

Consult a tire shop. You do not want to "guess" on a component as critical to your safety as a tire is.

I agree a tire shop can inspect and diagnose your TPMS sensor and valve. It may be more than just a bad core as these are much more complicated than a bicycle tire valve.

A Schrader valve is a Schrader valve, bicycle or car, and you won't be hurting anything.

Have done it myself on more than one car/bike. I think people would be surprised by the number of slow tire leaks that can be fixed by just putting a new core into the things.

On the safety side of things, the car has a pressure monitoring system, and even if the valve fails, it will leak out in a more or less controlled fashion and not a catastrophic blowout.

On the safety side of things, the car has a pressure monitoring system, and even if the valve fails, it will leak out in a more or less controlled fashion and not a catastrophic blowout.[/QUOTE]

If i understand you. You are saying that because of TPMS the air will not rush out. From what i know I think this is wrong. Air will rush out, blow out at whatever speed it can. The TPMS will not deter or slow down any flow.

On occasion i have sprayed a lubricant onto my valve . you might want to try this as a preventative measure but i'm not sure if it's leaking all ready, you might be too late. Can't remember what can i used( orange can with the word honey in it-- i think) but i know it wasn't WD-40.

What I was saying is if the Schrader valve fails, the air will leak out of the stem in a controlled fashion, and you will have enough control to slow down and stop, v.s. a blow out where you loose the entire sidewall and it goes instantly flat.

You are correct that the TPMS parts in the tire will have nothing to do with keeping air in the tire, which is why it is safe for the OP to just replace the core of the valve to see if it fixes his original problem.