I have a 2010 2.2L LT I inherited from my dad, and I keep having trouble with the tires on the right side losing air. I don't drive over potholes if I can help it or ram into anything with them; the "low pressure" light will just randomly come on. Sometimes it's accurate and yes, the tire is low for some reason, another time it did it it said I was around 24-26 psi in my right rear (which had been replaced because in that case, I did pop a tire). I checked it myself and it was at 35 psi (I keep my tires at 35--better mpg). Otherwise, it doesn't happen very frequently, just every so often (usually the right front tire) will lose air. It's never happened on the left side.

My friend and her fiance have an '07 Pontiac GTP and their tire sensors are constantly going off and the tires are always losing air. Is GM just half-arsing making wheels or something?

Has anybody else had this problem? My Coby is still under warranty so I can have the dealer check it out, but I'm curious to know if anyone else has had this issue.

*whew* Sorry. Long post. And sorry if this has come up before; I'm a newbie. ^_^;

 

If they are losing air then you probably have a nail in your tire or corrosion on the bead of the rim causing an air leak.

If your setting your tires to 35psi thats why your tire light is coming on I believe. GM's tire sensors are set to the computer to read a certain pressure reading for each vehicle depending on the specified pressure for the car. So cobalts are rated at 30psi I believe front/rear and if the sensor is getting a reading -5/+5 psi then I think it sets the TPM light.

 

even if your tire is fine you can loose air from the inner bleed stop on the stem....there is a tool to make sure they are tight you can get at any auto store...also the tpms sensors in the tires are known to act funny when it gets cold out

 

I harldy ever see valve stems just come loose. Yes it has happened before and I have seen it happen but main cause of tires loosing air is shitty gm rims getting massive amounts of corrosion on the inside somehow or it simply could be something stuck in the tire.

 

I know I don't have a nail or anything in the tires. I've checked numerous times, even on a lift. It's also not the 35 psi because it keeps saying they're low, and except for the one time, the particular tire it tells me does turn out to be low.

I just thought of something, though...There were scrapes on the right rear rim when I started driving the car (that rim is in the right front now since I popped the right front tire), so my dad might have done something to the rim. And the rim I scraped up is in the right rear, so maybe we did something to the rims. Because like I said, the left side hasn't had this problem: both rims on the left side aren't damaged.

I don't think it's the tire stems either, because I had to replace that one tire and the stem should be good on it. Sooo, perhaps I need new rims...those two on the right side look like poo, despite my efforts to touch them up.

Also, I think GM has been slacking on their rims...my mom's 2000 Venture hasn't had any such problems. But I didn't say that...

 

Maybe you cracked a rim.

 

You could always spray soapy water all over the offending wheel to see if you can find a leak (front and back) to triple check . Assuming no cracks in the wheel (and a leak free stem) then something is still wrong with the sensor or related systems.

 

this was happening to me as well (all tires), brought it into discount tire today and they said they cause was that the sensors were too lose. i guess the shop that rotated my tires last time fucked up

 

If you got a "tire rotation" then that would not cause a sensor to become loose.

 

yes true, but when i had them rotated i asked them to reset the sensors..so idk..im not excactly sure what they did i guess lol but they fixed it for free so its all good

 

Well to reset them on most GM cars you hold the lock and unlock buttons on the keyfob and and it will honk and go into TPM relearn mode. Then all they do is take a special tool around to each wheel and relearn the sensors one by ones and its tells the car which sensor is where.

 

yeah im aware of the keyfob trick now, i wasnt then though. and i wasnt sure if they just reset them or actually replaced them

 

They probably just reset them. Also doing the key fob trick isnt really helpful unless you have the TPM tool to relearn the sensors.

 

OP - Just cuz you cant see anything doesnt mean theres not a puncture with no visible hole. On a steel wheel thats a year old corrosion is not very likely so thats ruled out. Valve core could be loose/a sensor could be loose too. Use a deep socket and try to tighten that. Dont crank on it tho, dont wanna break the sensor. If you have scrapes on the rim it prolly got bent and is leaking there. Steel wheels bend like no other. could be a cracked rim but i dont think steel cracks. idk.

Cliff notes: Cracked rim, hole in tire, bent rim, loose sensor/valve core, fucked up sensor/TPMS. If its not any of that i have no clue.
Hope that helped :/
-Belle tire tech

Oh yea, if you got a tire rotation and they replaced your sensors please tell me where, id love to get 200$ in free **** lol

 

Some shops will remount and rebalance the tires as part of the rotation, so they may have gone as far as dropping the sensors out and breaking the beads on the tire to get a better balance. Unless they replaced the O rings and compression washers, its a strong chance that the sensors are loose or otherwise leaking.....

 

I have never heard of any shop doing a 4 dismount/mount and rebalance for a rotation. That is extremely pointless and a waste of time. Also I've worked at a GM dealer for a period of time and I have only once seen a sensor that was loose and was the cause of a tire leak.

To the op: Whatever tires are leaking, fill them to 35psi. Jack the car up or put it on a lift. Take a spray bottle with soap and water and spray it everywhere on the tire. Spin it around and completely spray the tire on the rubber. Wait a couple seconds and slowly spin the tire and try and see if its bubbling from anywhere. You can also spray the soap water around your valve stem and sensor and then take your valve stem cap off and squirt some more water on the valve stem core. I almost guarantee that you will find a leak and that it is probably a nail that is deeper into the tire that you can see. If you can't find it then take it to a shop and i'm sure they will find the leak.

 

My front tires are both losing air. No nails, no leaks from a soap test... Takes a week to go flat...

 

Did you spray soap around the bead of the rim?

 

Not on the backside yet. I plan to do that when I'm working on the fuel pump.

 

That's my next guess. Spray the entire part of the bead on both sides of the rim. Possible that there is corrosion on an 05. I've seen newer GM cars like 07's and what not with some pretty bad corrosion on the inside of the rim causing leaks.

Did you also spray around the valve stem and then inside the valve core?

 

Valve stems can dry rot, the edge of the rim can leak air, and the tires can leak air through dry rotted cracks if they are old enough. Tons of variables here.

 

well in my case the car is an 08 with 25k, theres no leak from my rims and tires have less than 10k on them

 

I agree, I'm just stating that we've run into this issue before.