Do I need to replace my 2003.5 G35 Sedan tires? I have Goodyear Eagle F1 All Season (235/50ZR17) which I purchased in 12/2007. I'm guessing I have put 30K miles on them and the treads still look decent. All four are losing air at a phenomenal rate, about 10psi/week. I inflate them to 40psi and after a few weeks they can be as low as 15psi.

I had a submerge leak test done on the one that was losing air the fastest and dealer said no leaks were found.

 

maybe you have a neighbor messin with you lol

 

you could be losing air at the valve stem. make sure it's not loose. bent rims maybe?

 

I wondered about losing it at the stem - is there a way to test for that? Wouldn't the submerge test show that?

I'm pretty sure the rims are straight.

 

By "Dealer" are you referring to the dealership? If that's where you went, mistake One. Go to a quality tire shop, let them know the issue you're having cause they deal with this kinda issue daily. Another thing you might check, kids put little rocks inside your valve stems when you screw the cap on it developes a small but constant leak....check 'em they're small pebbles.
Gary

 

i had a valve stem leak bc the sh!tty shop i made the mistake of having my tires mounted f'd up. the first guy inspected my wheel in the submersion tank for about 15 mins and couldn't find a leak. finally someone else came over to check it and they finally found the tiny leak from the valve stem. (moral of story: unless they are checking the valve stem they might not catch it the first time around)

you can also check it by wetting that area and applying pressure against the valve. you might be able to see little bubbles and even hear a little hiss coming through. good luck man and let us know what happens.

 

I checked for pebbles and didn't see any. I'll try the stem test, but the tires we installed ok and didn't leak until a few months ago. Thanks for the suggestions all!

 

Sorry to resurrect the old thread, but wanted to point out that if the vehicle has TPMS then the TPMS sending unit may need to be rebuilt when new tires are put on. Thought it might be helpful if anyone else has a similar issue.

 

Bubble test it. They don't lie. If no leaks then you need to bust your "friends".
You can do this with the wheels on the car inflated to 40 psi.

Remove the valve caps. Wipe a little bit of dish soap about 15% mixed with water in each valve and watch them.
Also, at the base of the valve stem where it pentetrates the wheel, not likely but may as well.

Your looking for bubbles to perk out which shows air leakage.

 

Did you get a TPMS rebuild kit? It's possible that it's leaking from the TPMS stem, but unlikely at all four. They are about 3 bucks for each wheel off amazon.

I'm guess the beads just aren't seating well on the rim's edge. My dad's car has this problem with his goodyear tires (forgot the model, it's a popular A/S tire on his beater). He's losing about 10 psi/month though.