RR601

So about a month ago I check my tire pressures and added about 2 psi. Using my handheld guage to check. Did not use it for 3 days. Then the tire pressure light was on when I go to use the car.
Went around and checked and the rear drivers side was low. Figured I had to of made a mistake myself.
Filled to 35 PSI.
Then a week later down by 2 PSI. Started checking everyday for a week and it stayed good. Only drove it once or twice during this time.
Take it out of town for a week with about 12 hours of driving. And no warning lights.
Get back home. Sits in garage a couple days and then the light is back on. So no leaks during the whole trip. But back home sitting the one tire Is 28 PSI down from 35.
Only thing makes sense to me is it gets parked and resting on an embedded nail or something. Since just leaks sometimes.
Lexus dealer a ways from me. But toyota dealer was close so had them look at it. But they just turned it over to what they call express service. Which looks like a bunch of young guys that just do things like tires and oil changes. Not even sure if they took the wheel off the car. Just said they pumped it up to 44 PSI and sprayed the wheel down real good and looked for leaks. Could not find anything. When I got home I checked and they had still left 44 PSI in that tire. There was no charge for the service which was nice but makes me wonder how good they checked.

I expect to have the same problem in a few days.

So what would you do next? Replace just the valve stem first? Or go ahead and replace the Tire also. If they cant pin point the leak seems only options.

Is a 2011 LS sport 42K miles. And Mich sport 3 tires about 2 years old with about 4K miles on them.

Makes leak makes no sense so not sure what to do. Just know I dont want to keep dealing with it.

​​​​​​​Thanks for any suggestions.

jud149

Go to a tire shop and have them check the tire.

RR601

Thats what I thought I was doing at the Toyota dealer tire shop.
There is a dedicated large tire shop in town that I may try next week. But if they dont find a leak I will need to at least try to replace something just not sure what. If I cant pin point the problem.
Thinking may have to get worse before they can find it.

Just like I could hear a small rubbing noise in the car going over bumps and slow speed. Lexus dealer could not find a problem. Had to wait a year for it to get worse before they found a bad air shock.

colfax

well I would go to the Discount Tire location in my city and you say there is a dedicated tire shop in your town so go there for sure

I suspect they would start by performing much the same testing pump it up and hold under water to detect leakage

I do remember Discount Tire telling me it matters how long it is held underwater to find very small developing leaks....

jmcraney

The pressures in the tires varies as a function of the tire temperature, going up about 1 PSI for every 10 deg F of temperature rise. You should only measure your tire pressure in the morning, before you have driven the car. If the ambient temperature varies that would be reflected in the pressure measurements. The TPMS warning thresholds are adjustable and it sounds like yours are set too high.

SW17LS

Is this an issue with only one tire?

Do you have chrome wheels on your LS?

DrMikeinPD

In my town the Discount Tire people tell everyone they have corroded wheels and need to buy a new set. Watch out for that.
They also like to tell people they have to replace all four tires when they only need to replace one or two.

LuvmyLS

Also, check your spare. It’s in the trunk. The tire pressure of the spare will be displayed on the dash with the other four, but you won’t know which is for any given tire. Lots of folks on this site chase “leaky tires” and “malfunctioning TPS” when all they need is a **** of air in the spare tire.

RR601

But I am actually losing air in the one problem wheel. Just that I can go a week and many miles with it not losing any air. Then it starts losing again. I think the TSPM is working like it should. It lets me know when that one tire is low. I confirm with my guage and add some sir.
Cant see how this would matter. But I manually check my air pressure in the winter each year. Sometimes need to add a pound or 2. My problem did start a couple days after I did this. Seems impossible but strange started at same time. Could it be a valve stem leaking. But since it only leaks sometimes. It is not leaking when I checked it or when toyota did.

RR601

Yes, did check that the first time the problem started but the spare is fine. I do know what wheel. It is rear drivers side that loses air but only sometimes.
Example is it leaks just sitting in the garage over a few days. But does not over a week which includes a 10 hour trip.

SW17LS

Do you have chrome wheels?

RR601

Yes, just the one.
Not chrome wheels. The stock 19" ones that come on the LS460 sport.
But know what you mean. I had a problem in the 90's when had a LS400 with chrome wheels. They had to install tires with rubber cement around the rims.

SW17LS

The issue is chrome flaking around the bead.

Have you owned the car since new? I would still have them dismount the tire and check the bead.

jmcraney

This discussion thread on wheel leaks that we had a few years ago might be of interest: https://www.clublexus.com/forums/ls-...corrosion.html

Chaos236

iTrader: (1)

Discount tire does free air checks. You can go monthly.
If DIY use the same air gauge. They very.