jdog0411

I've got a curious issue with the right rear Michelin on my C7. The car only has 175 miles on it, so it's barely been driven. I got in the other day and the information center said that the right rear tire had low pressure. I took a look and it did measure at only 22psi.

I aired it up and then inspected the tire the best I could with it still mounted on the car. I can't see any obvious holes, tears or objects sticking out of the tire. I was out of town all week, so the car sat after I filled it to 35psi. I checked it again today and it's down to 29psi so there is an obvious leak.

Is there something besides a puncture that could be causing the air leak? Leaky valve stem, tps sensor, etc? I didn't get the tire/wheel warranty, so before I take it in I want to be prepared for possible issues.

Bill Dearborn

Take it in and have them look at it. Most anything that is wrong will be covered under the warranty unless there is damage caused by you or something you ran over. Even then they may cover it. Things that could be wrong are a porous wheel, bad tire pressure sensor, a leak around the bead or a puncture. Most of that is covered under the warranty and the charge for repairing a puncture isn't all that high even at a dealership.

Bill

Al Engel

Two possibilities you may want to check---- the Tire Pressure Sensor (Valve Stem) has a rubber gasket between the sensor base and the wheel (inside the wheel / not visible from the outside). Put some soapy water around the valve stem where it comes out of the wheel, and if bubles are detected... that's the problem. Try tightening the valve sterm nut - - that may fix the problem, but the fix may require a new rubber gasket on the tire pressure sensor / valve stem. The other possibility is aluminum wheel porosity (air seaping through the aluminum wheel). This was a problem when aluminum wheels first appeard three decades ago and has generally disappeared on factory OEM wheels - - but it is 'possible'. The solution here is a new wheel. The good news is both issue are 'warantee issues' and Mr. Goodwrench should be able to easily resolve. Good luck - happy motoring and 'save the wave'.

Kracka

Warranty...probably a leaky stem. On my last car the threads were cut too deep on the metal valve stem/TPMS sensor and it leaked a small amount of air.

red1996lt4

My RR tire developed a slow leak. Added air every couple of days until I decided to have dealer check. Had a "horseshoe" nail. Dealer charged $15 to patch. No air loss now.

jdog0411

Thanks everyone for the information, that is helpful. I will take it in and have the dealer take a look.

Modshack

Happened to me too.....NO visible damage or punctures..
Pulled the wheel off and inspected carefully...Nothing.
Finally I noticed a very small mark on the center tread section. No visible nail or puncture, just a small 1/8" sipe in the tire. Shot it with soapy water and sure enough, there was a VERY small leak. It's a miracle I even found it as it was virtually invisible. Patched and has been fine ever since..