Tire loses pressure seemingly only when driven

[horse123]

I'm heading out tonight and if there's a tire shop open, I'll take it there. Anyway, for the past month or two my extreme performance summer tire on an 18 inch wheel has leaked, seemingly only when I drive. I feel like I could let it sit for a week and only lose maybe 4 PSI, but if I drive 1/4 of a mile I lose 10-20PSI. It seems to level off around 22-25PSI (recommended 33). It doesn't appear to have a puncture in it that I can see, but I guess it could be on the inner sidewall, which is extremely unlikely.

Any ideas? Could just a simple reseat possibly help? Should I just take it to the shop and let them check it out?

Forgot to mention, these tires and wheels are both only about a year old right now. Should not be a bad valve stem, but I guess it's possible. I don't have any spray bottles with soap water in them here.

 

[Quattro Pete]

Seems like the leak is between the tire and the rim. The air escapes when the tire flexes when rotating while driving down the road. You could try reseating. While you have the tire off, check to see if rim lips are intact.

Rust is probably unlikely since I'm guessing these are not steel wheels.

 

[jeepman3071]

It might be the bead. A re-seal might fix it.

The previous aluminum wheels I had on my Jeep tended to leak right around the bead. Jeep wheels are known for this since the wheels will start to corrode right around where the tire seals. The leak was slow, but it was a pain having to fill the tires up when they were low. I ended up scoring some new old stock wheels on Craigslist and the problem is gone.

 

[901Memphis]

I had corrosion issues on aluminum wheels causing leaks before, the shop ran some sort of grinder or sander inside the lip and it fixed the seating issues between the bead and rim.

 

[SatinSilver]

Could very well be a leak around the rim. If you have a Discount Tire around they offer free flat repairs. They should take their time to figure it out since all they do is tires unlike most tire places that offer a variety of services.

I had rim leaks on an Accord and had to have all four tires remounted.

 

[Andrew1972]

I had similar issue and once a bad valve stem and the other time tire needed to be reseated/mounted.

Take it somewhere, it's pretty cheap typically to repair a tire issue.

 

[fdcg27]

I had this happen once with a newly mounted set of Michelins.
The right rear was almost flat by the time I drove twenty five or so miles home.
I inflated the tire and it stayed up until the following morning, to my surprise.
I drove the car to work and it was again virtually flat after twenty five miles.
The tire only lost air when the car was driven?
WTH?
I took it back to the shop that had mounted the tires and they decided that it must be the valve stem.
They put a new valve in that wheel and all was well after that.
Strange but true.

 

[horse123]

I set up an appointment tomorrow with a tire shop in town.

 

[dparm]

Originally Posted By: 901Memphis
I had corrosion issues on aluminum wheels causing leaks before, the shop ran some sort of grinder or sander inside the lip and it fixed the seating issues between the bead and rim.



Yep, this is a possibility. Have your tire shop check the wheels for corrosion. Another similar problem is when the clearcoat on a painted wheel starts to oxidize (from overly harsh wheel cleaners, or just plain old UV).

 

[69GTX]

My last daily driver had alloy wheels that all leaked due to corrosion...or at least that's what I assumed. The worst ones would lose 5-10 psi in a week. I dutifully charged them up until the car finally died of other causes. I even went so far as to buy 2 used rims that weren't nearly as corroded. Those leaked too. The leakage didn't speed up when the car was driven.

 

[4wheeldog]

I had an issue with the dust cap seal being inverted, so that the valve was held very slightly open by the cap. Turned the seal right way round, domed side in, and all was right.

I would check to make sure the core is tight in the stem. If that is not it, I would change the stem. Good luck.

 

[SirTanon]

I had an issue on one of the tires on my Fusion. Turns out they had forgotten to remove a sticker on the inside lip of the tire.. it was JUST thick enough to allow air to escape when things were just right.

They took the tire off, removed it, and re-seated. Problem gone.

 

[Wolf359]

Many places do cheap or free tire repairs. I usually go to Town Fair tire, they do free flat repairs and I think the last time I went there, they only charged me $4 to balance the tire, the repair was free. I think Goodyear also does free flat repairs now.

 

[JC1]

Originally Posted By: 901Memphis
I had corrosion issues on aluminum wheels causing leaks before, the shop ran some sort of grinder or sander inside the lip and it fixed the seating issues between the bead and rim.


+1 that is probably what is happening.

 

[tcp71]

Carefully check for a thin nail or wire. I had a nearly invisible wire poking through and it only leaked while driving.

 

[horse123]

Well all I can say is I'm surprised. It was a dent in the inside part of the rim. I don't recall hitting anything particularly hard.

A re-seat just turned into a new set of wheels. Perhaps ones with a little more sidewall. These 225/40s are just dent/rash magnets.

 

[Traction]

Doesn't surprise me at all. I have seen it quite a few times, and you can even see a very small part for the tire to seal in from wear marks around the dent. The backside of the wheel is very flexible, like the open end of a 5 gallon bucket. A lot of people have bent wheels, but don't even know it, because it won't even show on the front side of the wheel. And, it doesn't take that much of a pot hole to bend most wheels anymore. Never see it on 70+ series tires though.

 

[horse123]

These wheels had a good run. But low profile performance tires and cheap low pressure cast aluminum wheels aren't for me anymore. I'm going to sell them on cl for whatever I can get and but an inch smaller rim and some high performance all seasons.

 

[HTSS_TR]

Originally Posted By: horse123
Well all I can say is I'm surprised. It was a dent in the inside part of the rim. I don't recall hitting anything particularly hard.

A re-seat just turned into a new set of wheels. Perhaps ones with a little more sidewall. These 225/40s are just dent/rash magnets.

Six months ago my passenger front of E430 had a very loud pop, the tire was completely flat but I was on a 2 lanes mountain road so I could not stop. I drove slowly around 20-25 MPH with emergency light on for about 8-10 miles to get to a turn out to change the tire. During the drive I could smell the rubber burning.

I went to America's Tire to buy a new set, all tires were between 2/32" and 3/32" so they gave me some prorate. The flat tire had 1" diameter hold on the inside about 1/2 way up from the tread. The wheel was bent a little(they showed it to me), but no air leak. I was very surprise that damage wasn't worse than that.

They told me watch out but no need for new wheel if it hold air and no shaking nor handling effect.

By the way the OEM size is 235/45-17.