Tire leaking below 32F (0C)

Alloy rims, right?

Have the corrosion cleaned from the bead area

If the tire has low pressure below 32 and recovers WITHOUT adding any air, this is normal. The tire will gain 3-6 pounds as it warms up.

There may not be anything wrong. As the outside air gets colder, your tire loses pressure naturally.

Just of law of physics.

Agreed, that's a rim leak.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

"Mike Romain" wrote

And while you're down there cleaning the rim beads, make sure to put some valve caps on, otherwise you might get a drop of water down in the valve, and when it freezes and expands, it can push the valve open and let the air out.

If it's an old steel rim it's probably from rust on the bead. Also, the rubber on an older tire gets so hard that it won't conform as well to the uneven surface caused by the rust. I've posted before about silly ways to fix such leaks and they work. You could try squirting oil into the bead area to soften up the rust. You have to do both sides of the tire, not just the outer side. This technique can help you get by or use up the tread on an old tire, but think about fixing that rim when its time for a new tire.