CARuiser

I have 19UX250H. This is my first car with run flats.

My problem is the back left tire is showing the tire pressure to be 28psi in the morning and 24 just as I got home this evening. All other tires are between 30-32psi. I don't hear any hissing. But I'm not sure what the issue is. I do have a low pressure light on, but would any other light appear if it was a bonafide flat?

I'll be checking it checked, but im impatient and looking for an immediate answer. Thanks in advance.

Jimmy3864

Sounds like a slow leak, could be at the valve or around rim or a small puncture with the foreign object still embedded. Since is dropping during day, best to get it checked out. The more you run on an under inflated run flat, the weaker the extra stiff sidewall will become thus losing its effectiveness.

tofuprod

If you want an "immediate" resolution - since you're local to me:
1. spray soapy water across the rim and tire, everywhere, anywhere that bubbles, indicates a hole/leak.
However, since that takes some manual effort to do.. my second suggestion i-
2. Drive to your local Discount Tire, they will plug and patch it for free.
3. If you're super local to me (as in the 630), feel free to come by me and I'll be happy to help if anything else.

RXWes

The first day it gets cold here in Florida. I know I will need to put air in one of my tires. Never fails

Not sure why. But the TPS light will come on. And one tire will be 5 PSI lower than the others. It’s not flat. It’s just low

If a tire is flat you will know. If it’s just low enough to set off the TPS. It just needs air put back in.

Set all 4 for the same pressure and the light will go out.

CARuiser

Regretfully, one of the tires had a nail in the sidewall. $308.00 out the door. Probably paid $50.00 bucks more going through the dealer. Paid for the convenience, since I was already there.

tofuprod

Sorry to hear man, at least you caught it before it became a more serious issue.

When in doubt and you can't really take the tire off the rim and or the rim/tire off of the hub - take water and just a bit of dish soap (so soapy water..), and spray it around the whole wheel, inside and out, look for air bubbles if any, if there are- there's your leak.

CARuiser

Thanks for the suggestion. wish I would've tried it before taking it in. I was secretly hoping it was an easy fix, like a patch could of repaired.

Does anyone know if the wheel and tire insurance would have covered this?

tofuprod

DiscountTire does with their Road Hazard add-on and I believe Lexus may, as our SA gave that to us when we got tires there as well.

I've sent you a PM so if you need help - feel free to reply.