Estimate my car repair cost (TPMS sensor-related)

December 19, 2012 5:10 PM

I broke a part of my car's tire valve (the TPMS sensor, maybe?), dropped my car off at the tire shop and realized I have no idea how much this will set me back. Does anyone have an idea what these repairs might run me?

(Apologies in advance for my complete lack of correct car part terminology!)

My tire pressure light came on last week (likely due to cooler temps), and I finally went out tonight to top off my tires with the free air from my gas station. The first three filled fine, and the fourth did as well, but when I pulled the air pump thing off the fourth tire and went to screw the cap back on, something happened, the cap flew off the car, and the tire immediately started spewing air and going flat. The cap had a small piece of metal stuck in it (which I believe might be my TPMS sensor, thank you Google) and I wasn't able to screw that back on the valve.

I was able to fill the tire a bit more and stole a valve cap from another tire, which stayed on the valve but wasn't a super tight fit. But this at least allowed me to get my car to the tire shop without going flat.

As it's the evening, they need to keep my car overnight, and I left without asking how much a repair like this might run me. Finances are a little tight right now, as it's the holidays, so I'm just trying to get an idea if this is a quick fix or if I'm going to be shelling out a good chunk of change tomorrow. Any amateur (or pro!) mechanics want to give me their best guess?

It's a 2010 Mazda 3, and I'm in Baltimore with my car at a Firestone shop, if that helps.

posted by JannaK to Travel & Transportation (11 answers total)

Best answer: The part that came out of the valve might just have been part or all of the valve core (on the left in the top illustration). They're easily replaceable, though you need a special tool, and are (nearly) free as air. You could probably replace it yourself, if that is what went wrong. It's possible that the valve stem is damaged, but that's not a complicated or expensive repair either--the valve isn't integral to the tire--though probably best left to the tire shop.
posted by pullayup at 5:29 PM on December 19, 2012 [1 favorite]

If it was a TPMS sensor, the whole sensor costs $30-50, and the stems (which are replaceable) run about $10. I don't know what your shop will charge you, though.
posted by pullayup at 5:33 PM on December 19, 2012

I replaced the sensor in one of my tires for my work truck (2010 Ford F-150) and it was something like $125, but those are internal to the rim as far as I know. It sounds to me like you lost a valve stem.
posted by sanka at 6:04 PM on December 19, 2012

Yeah, the sensor sits inside the rim above the valve stem, and is held in place by a grommet that threads on to the stem outside the rim. You don't have to remove the tire to get at it, but you at least have to break the bead so you can reach in to extract and replace it (and then you have to re-seal the bead). It's something best left to a tire shop unless you're enterprising.
posted by pullayup at 6:18 PM on December 19, 2012

Response by poster: Aha! Thank you for the link puyallup! Now I at least know the correct terminology. I definitely broke the valve core off of the valve stem - the core was the metal piece stuck in my valve cap. The stem didn't appear to be in great shape either, as I had some trouble getting another valve cap back on it, so I'm assuming that is also something that'll need replacement or repair. As I am not terribly enterprising (at least when it comes to car repairs), I think I'll be sticking with the tire shop, but luckily this isn't sounding too financially debilitating.
posted by JannaK at 6:34 PM on December 19, 2012

Lucky you drove right to a tire shop and not back home. I can't imagine a cap would have stayed on there long.
posted by sanka at 6:45 PM on December 19, 2012

The important information here is that the choices available boil down to either get it fixed, or don't get it replaced now and then get the tire AND the core replaced when the tire is ruined. Which you don't want to do. With a plastic valve cap, I'm impressed it stayed on.
posted by jgreco at 3:38 AM on December 20, 2012

Best answer: The valve core corroded on two of my tires and replacing it meant replacing the TPMS. They wanted $125 a piece to replace the whole thing.

To be honest? I just put regular cores/stems back in and have learned to ignore the little TPMS light.
posted by jerseygirl at 8:23 AM on December 20, 2012

Response by poster: Thanks all! The new TPMS sensor ran $125, plus about $40 for labor. Not my ideal way to spend my money, but I guess it's good that it's fixed. Normally I'd be fine letting the TPMS light go forever, as jerseygirl mentioned, but my car has to pass inspection soon to get my title transferred (I just moved here), and I'm guessing that would be a bit of a red flag.
posted by JannaK at 3:23 PM on December 20, 2012

It wasn't in Massachusetts. Tire pressure monitoring wasn't required safety equipment. YMMV.
posted by jerseygirl at 8:05 PM on December 20, 2012

One thing I learned the hard way with TPMS sensors--do not ever use a non-plastic tire cap on them. Galvanic corrosion is not your friend! They will corrode and fall apart.
posted by Pryde at 4:15 PM on December 21, 2012