Daughters car.
She commented yesterday she had one tire that leaked down enough to give her a warning (maybe 5 pounds). VERY slowly... only about once every 4 to 6 weeks. She said two trips to the tire shop failed to find a leak.
I found it in two minuets after spraying windex on the valve stem. A super slow leak coming from the area I circled in yellow in the photo. I tightened the nut a bit ever so gently on the stem to no effect. Knowing nothing about these sensors I aired up the tire and showed my daughter where the leak was so she could show the tire tech next time.

So should it tighten up more or will it have to come out and resealed and or be replaced?

She says she may just let it leak and top it off as needed I didn't particularly like that idea.

quote:

So should it tighten up more or will it have to come out and resealed and or be replaced?

Yes. Tightening it more may well overtighten and break it. The nut is low torque to start with. If you're lucky, it can be resealed. Sometimes the sensor doesn't survive being removed and replaced no matter how carefully.

You could loosen the hex and there's probably an o ring under there somewhere but a new one (that requires partial tire removal) is likely what it takes to fix.
Unless it's a really expensive part, I'd take it to a good tire shop and let them replace it. Letting the tire get low and running it that way will cause all sorts of potential hazards and wear and it may not continue to loose air at such a small rate.

I had to replace mine. Local shop charged 50.00 installed and rebalance the tire.

The batteries typically last 8 to 10 years, so you may simply replace. Check Rockauto, as they have service kits. Dependant on the make, may need a shop to re-sync / re-program. I recall the typical torque spec is very low. Easy to over tighten.

Ok guys, thanks.

I'll have her take it to a shop I trust and let them do as needed. I didn't figure I wanted to mess with it myself.

It's on a 2017 Infinity QX60, not that it should matter... so just 4 years old.

Most can be rebuilt with a new seal kit.

I had a 2007 Chevy TrailBlazer with a wonky TPMS sensor. The dealership (who, btw, usually treated me quite well) wanted to swap 'em all out. Discount Tire said "Nonsense. Bring it by." They identified the culprit, swapped it out, and reprogrammed the system for it. They didn't even charge me for the diagnostic, which they usually do. (Maybe the fact I'm a long-time customer had something to do with that?)

I currently have a tire behaving like your daughter's, cparktd. Doesn't lose air fast enough to have become annoying enough to go to the trouble of actually doing anything about it, though

quote:

Originally posted by ensigmatic:
I had a 2007 Chevy TrailBlazer with a wonky TPMS sensor. The dealership (who, btw, usually treated me quite well) wanted to swap 'em all out. Discount Tire said "Nonsense. Bring it by." They identified the culprit, swapped it out, and reprogrammed the system for it. They didn't even charge me for the diagnostic, which they usually do. (Maybe the fact I'm a long-time customer had something to do with that?)

I currently have a tire behaving like your daughter's, cparktd. Doesn't lose air fast enough to have become annoying enough to go to the trouble of actually doing anything about it, though

And your experience is the exact opposite of mine. The local Discount Tire tried to sell me on replacing all four of my TPMS when one quit. I told him to replace the bad one only, his line “Soon the rest of them will go bad” rung hollow with me.

Three years later, nine year old vehicle with 114k and the other three are still functioning.

I had this problem when I got new tires and sensors from Costco. The tech said he had to remove the whole stem and installed new seals.

I have the valve stem that has the rubber seal....from 1990. From reading other sources, the valve stem can be tightened too much causing the seal to crack. In my case, it is probably age.

4 years old, an o ring kit should do it.

quote:

Originally posted by ensigmatic:
I had a 2007 Chevy TrailBlazer with a wonky TPMS sensor. The dealership (who, btw, usually treated me quite well) wanted to swap 'em all out. Discount Tire said "Nonsense. Bring it by." They identified the culprit, swapped it out, and reprogrammed the system for it. They didn't even charge me for the diagnostic, which they usually do. (Maybe the fact I'm a long-time customer had something to do with that?)

Assuming this was recently, and not when the car was new, your dealership was correct. That's a 15 year old car. TPMS sensors have lithium batteries in them that are only good for 8 to 11 years usually. If you want the sensors to work correctly after that, you replace the sensors with new ones. Replacing ONE sensor now, that is that old, means you'll be diagnosing and replacing three more sensors in about 12-18 months. Better to do them all at the same time, when they are that old.

For what its worth, Walmart replaces sensors for about $28 each installed, which was the cheapest price I have found locally. So about $120 for all four new sensors, which was $100 cheaper than the tire store and $150 cheaper than the dealership.

quote:

Originally posted by shovelhead:
And your experience is the exact opposite of mine. The local Discount Tire tried to sell me on replacing all four of my TPMS when one quit. I told him to replace the bad one only, his line “Soon the rest of them will go bad” rung hollow with me.

Three years later, nine year old vehicle with 114k and the other three are still functioning.

You should replace all of them at the same time when one goes bad. So dont get mad at the tire store... they offered sound advice.

New car time... that is the only solution

quote:

Originally posted by bubbatime:
Replacing ONE sensor now, that is that old, means you'll be diagnosing and replacing three more sensors in about 12-18 months. Better to do them all at the same time, when they are that old.

Except, in this case, I ended-up replacing the TrailBlazer before I lost another sensor, so I was money ahead

All 4 of my sensors on my 14 Acura TL piss air. Only about 1lb week so I am holding off until I put new tires on in November. TPMS = big $ for Dealerships and Tire/Repair shops.

tpms technology isn't worth the headache. I removed all of mine and replaced them with regular rubber valve stems. The tpms light on the dash is lit up more or less all the time, but it doesn't make much noise, so it's easy to ignore. tpms was a bad idea to begin with, and it still is. If your state auto inspection laws don't require working tpms systems, just ditch them when they wear out, unless you like government auto regulation stupidity. But if you have the income to support the technology, and you don't watch tire pressures every few months, then I retract. But, in that case, don't complain about the cost of paying a shop to replace the pieces and recalibrate the system.

I’m in the other camp. None of my four cars have had them go bad and they have consistently notified me of trouble before I would have known otherwise. Not a fan f the kind that just generically says one of the tires is low but the newer ones tell me which corner which is nice.

Until the pot metal stems lose their internal integrity with regular road conditions, uv, heat, and dirt etc., and snap off with the least bit of road trash. Ask me how I know. Regular old rubber valve stems take a licking and keep on ticking. But replace them with each new set of tires, don't keep using the old stems with each set of new tires. That way the old stems are less likely to leak as they oxidize and wear out. Lots of brand new tires are damaged by low air by keeping old valve stems. You generally have to ask to have them replaced, they're not expensive to replace