I've been experiencing a slow leak on my left rear (tire). Took it to our local Goodyear Tire Center yesterday and they told me they could not find anything wrong, but oh, BTW, my tires were "dry rotted" and needed to be replaced. Yeah, right. Today I took it to my usual local guy and they told me the TPMS was leaking at the valve and that I really should take it to the dealer to have the module replaced. And, they told me my tires were just fine, otherwise. They didn't charge me a dime to find the leak or for the advice. It's nice to know there are still some honest shops and competent people out there.

So it's off to the dealer soon for this and a couple of other minor issues as well as the 40,000 miler.

 

TPMS valve stems require specific and very low installation torque or they leak. The usual fault is too much torque was applied causing the seal to leak slowly at the rim.

Old style TPMS valve stems also leaked even when correctly installed. Make sure your wheels all have to updated valve stems.

"Tire rot" is slang for old age tires. After five years of regular heat cycling the rubber goes hard and the tires are basically junk. If you don't replace them you are driving on unsafe tires. Between 5 and 10 years the tires are pretty much useless, especially in the wet. After ten years any car tire may fail catastrophically and without warning. So, tire guys are not blowing smoke when they talk about tire rot, just using technically inaccurate terminology. Check the DOT week and year of manufacture on your tires and take action accordingly.

Tread depth remaining is only relevant if you drive 10,000 miles per year or more on one set of tires. Otherwise you should replace tires long before they wear out, examined visually.