innerconx

Hi Guys
Wondering if anyone else has run into this.

I have a drivers side rear tire loosing air pressure at a pretty good rate - maybe 8 to 10 psi over and 8 hour period. Tire has been checked by the dealer for bead leaks, punctures and they say (I have to believe them one of the mechanics is my nephew) valve stem leaks. All come up as negatives. No viable leaks even with tanks tests etc.

It seems to me I loose more air pressure when the car is moving then when its sitting.

Passenger side exhibits the same behavior - but not is such a dramatic way.

The only other thing I can think of is maybe the valve itself isn't seated properly? I know there is a rubber grommet on the TP sensor.

My thought is if this doesn't get resolved in the upcoming rim swap (car came with chrome - swapping for black) or my valve stem idea is a flop, I'd insist on tire replacement which in itself could be an issue because I hear that the Michelins are hard to come by.

Especially on a car with just 200 miles on it

Any ideas or suggestions?

Thanks in advance.

Thomasmoto

Either way, your dealership should resolve it. It's not your burdon to find out what is causing it, its theirs. Just document it with your phone, in case they don't believe you for some reason, and show them or their district service representative. I've worked at a dealership before. We used to replace wheels and tires fairly regularly to solve problems. You might want to wait until after you get the new wheels and see if it continues first. If it doesn't, great and go on. The less they have your car the better.

innerconx

You're absolutely right. I just like to know whats going on.

And its good to know with your experience at a dealership that replacing tires and rims is not something out of the ordinary.

Rim swap happens Wed or Thursday and I am trying to cut a deal where I can keep the chromes as well

Thanks again for the response - I appreciate it.

badhabit_wb

It's odd that 2 are doing it. I've seen rims leak and I've seen leaks when trash gets between the bead and the rim but it's strange that 2 are doing it, especially on opposite sides of the car. Are you checking with a tire gauge or using the dash gauge? I guess if you've had to add air something strange is going on.

innerconx

Same side of the car and checking with both the on board monitors and a tire pressure gauge - they read the same.

badhabit_wb

If it's the same side of the car there could be debris in the tires. I've had that happen, off road, with other vehicles especially after sliding sideways. Not saying that's what happened but you never know what happened before you picked the car up.

innerconx

I thought the same thing - I haven't had it sideways -yet - and the car had 3 miles on it when I picked it up

badhabit_wb

If it was a normal tire I'd say unmount them and check the beads for trash. So many people have had problems getting the beads to seat that I would make sure they know what they're doing when they do that. It still sounds like something that happened on that side but who knows.

apex97

My C6 Z07 with Cup2 tires has had an intermittent slow leak in the left rear since new..it comes and goes and no one seems to be able to find it...and of course if I show it to any tire dealer they tell me the tires are too worn out to service..been saying that since the first week I owned it..morons.