Loss of Tire Pressure at Highway Speeds
03-14-2013, 05:27 PM
#21
Heel & Toe
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As suggested, I'm going to have the tire taken off the rim and have everything inspected, if it persists I'll just get a new TPMS for that wheel. I'll let everyone know what I find out.
03-14-2013, 07:57 PM
#22
Melting Slicks
I would think the tech would've checked the pressure with an actual gauge (as might you have at least once, not just the DIC readout), but maybe not.
Of most suggestions above, I'd guess the nut, the TPMS itself (needing replacement), or a nail/screw that's not visible. These TPMSs are supposed to last 10 years or more, but if your car's an '07 it could've been produced in mid '06---that puts it at about 7 years old now potentially. Wera's post has some potential issues, too.
BTW, does it leak at all if you leave it in the garage overnight?
Of most suggestions above, I'd guess the nut, the TPMS itself (needing replacement), or a nail/screw that's not visible. These TPMSs are supposed to last 10 years or more, but if your car's an '07 it could've been produced in mid '06---that puts it at about 7 years old now potentially. Wera's post has some potential issues, too.
BTW, does it leak at all if you leave it in the garage overnight?
03-14-2013, 08:33 PM
#23
Race Director
Sorry it's a 2007 with OEM rims and tires. I'm the 2nd owner, bought it in December 2012 and it had 9000 miles on the odometer. It has 12,000 miles on it now and the rim has now scuffs, scrapes or other signs of hard wear and the tires have about 90% tread left. Other then the drive home from the dealer this was the first it was driven on the interstate.
03-14-2013, 09:41 PM
#25
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I had practically the same thing happen to me on my 08 I just got a couple weeks back. The Cadillac Dealer I bought it from put on new SuperCar F1s. I drove about 100 miles home. Next day Low Tire pressure going off. Dropped down to 22 PSI. I filled it to match the right front tire (which I later found out they had over-inflated to 38 psi). Car sat for a couple days, no major loss (was maybe like 2-3 PSI at most). Took another trip (about 35 miles each way) and the pressure dropped like crazy. Ended up taking it to NTB to see if I hit a nail or something, they took the tire off and played with it for an hour, found nothing. Ended up going to a Chevy Dealer around my way to see what they said. They did all sorts of tests on the valves, TPMs and tire, and the guy said he found nothing. He recommended re-mounting/sealing the tire. Said he can't guarantee it would fix it, but it was only $50. I had it done (they also CORRECTLY adjusted the PSI in all my tires) on this past Saturday, probably put another 100 miles on the car (highway/city) since and haven't had any PSI drops.
So it could be something simple like this.
So it could be something simple like this.
03-15-2013, 02:49 AM
#26
Racer
Mystery Tire pressure loss
I searched the forum for this very issue and found several solutions, but they have not worked for me. My Dilemma: The wife and I recently took a trip; about 400 miles each way and I checked the tire pressure before leaving to make sure all tires were 30 PSI cold. After hitting the interstate I was averaging about 80 mph while driving and then 2 hours into the drive I get a low tire pressure warning for my LF tire.
The tire pressure dropped to 23 PSI while the others were constant at around 34/35 PSI. I stopped, checked the tire found no nails, screws or punctures and inflated the tire to 35 PSI and then continued on. As I drove I kept watching the TPMS for that tire and it would drop 1 PSI about every 15 minutes so I tried varying my speed between 70 & 80 mph, but it still dropped at that rate and I had to stop about every 2 hours to re-inflate.
When we got to our destination it was late at night so I re-inflated the tire again and checked into the hotel. The next morning there was no loss of pressure, but I took it to a tire center and had them pressure check the tire, check the valve stem, and they even submerged it under water looking for leaks -- nothing.
We drove around the destination city at normal city traffic speeds (not exceeding 60 mph) for several days with no loss of tire pressure. But on the return trip home we had the loss of PSI and stopped every 2 hrs to re-inflate.
Got back home, checked the forum and found similar issues with the torque spec of the valve stem and the TPMS o-ring seal being possible culprits. Took vette to the Chevy dealer and had both those items checked as well as having tire pressure tested afterwards. Was told everything checked out. I hit the interstate again for a 30 minute drive and its still losing 1 PSI about every 15 minutes.
Thanks in advance and sorry for the long post, but any ideas about a fix would be appreciated. Also, the vette sitting in the garage for a few days or normal driving around town still no loss of PSI.
The tire pressure dropped to 23 PSI while the others were constant at around 34/35 PSI. I stopped, checked the tire found no nails, screws or punctures and inflated the tire to 35 PSI and then continued on. As I drove I kept watching the TPMS for that tire and it would drop 1 PSI about every 15 minutes so I tried varying my speed between 70 & 80 mph, but it still dropped at that rate and I had to stop about every 2 hours to re-inflate.
When we got to our destination it was late at night so I re-inflated the tire again and checked into the hotel. The next morning there was no loss of pressure, but I took it to a tire center and had them pressure check the tire, check the valve stem, and they even submerged it under water looking for leaks -- nothing.
We drove around the destination city at normal city traffic speeds (not exceeding 60 mph) for several days with no loss of tire pressure. But on the return trip home we had the loss of PSI and stopped every 2 hrs to re-inflate.
Got back home, checked the forum and found similar issues with the torque spec of the valve stem and the TPMS o-ring seal being possible culprits. Took vette to the Chevy dealer and had both those items checked as well as having tire pressure tested afterwards. Was told everything checked out. I hit the interstate again for a 30 minute drive and its still losing 1 PSI about every 15 minutes.
Thanks in advance and sorry for the long post, but any ideas about a fix would be appreciated. Also, the vette sitting in the garage for a few days or normal driving around town still no loss of PSI.
Hope this helps
03-15-2013, 05:17 AM
#27
I had the same issue with my new Cray Hawks. City driving was fine but I lost pressure on the freeways. Took the Vette back and had them TIGHTEN all the valve stems and TPMS stems. No more pressure loss problem. My theory is that the faster you go, the more rotational force is exerted on anything that protrudes from the wheel. If a valve stem is "loose" it will move enough to cause a gradual pressure loss. I call it the teacup theory and if you've ever riden on them, you know what happens when you tilt your head back.
03-15-2013, 10:23 PM
#29
Team Owner
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St. Jude Donor '13
If you go to tighten the TPMS nuts, be careful. The torque spec is 61 INCH-pounds. You can do that with just two fingers on my 3/8" drive beam torque wrench.
