Endzone

It doesn't necessarily have to be a problem in the tire or the valve stem. I just recently had this experience with a rim on my 2003 Avalon. I won't bore you with the details, but the guy at Discount Tire said he especially sees this problem with 2007 and newer Lexus cars. He said especially if the rims are chrome and the chrome begins to peel. And it is possible for even alloy rims to get small cracks inside of them or corrosion around the lip of the rim and cause the problem.

I solved my problem by getting a salvage yard rim at a yard called LKQ in south Dallas. Yes it was $103, but a new one from Toyota is $447.

5Ws

Endzone:
Yeah, leak at the bead. You can test for it by spraying soapy water at the tire/rim interface, with inflatted tire. If leak, it will eventually reveal itself with bubbles.

I saw it a lot on steel rims, with rust/pitting along the bead. I scrubbed the rim bead with a wire brush, which knocked off the rust. Still, the pits remained. Following that, I applied bead sealer. Worked every time. Even worked when the tire was the problem, like small tear on the tire bead. I've salavaged a couple buddies tires this way.

If bead leak is the problem: put this stuff on the rim and bead before pumping up the tire and sealing the bead.

https://www.amazon.com/Group%C2%AE-1.../dp/B000GKD722

BTW. You def got a better deal at the yard than the dealer. The price sounds about right.

Richard