Ok so i posted here about a month ago about a run flat that was losing air in a slow leak fashion. So I took them to two different places and had the tires dunked and nothing was found. Rims arent bent and the pressure indicators work. I read about mini owners who jsut had to keep adding air and just dealt with it. So this week the tire light goes off, i duck over into a service station and pressure was down to 25 from 38. Its a different tire though, the front passenger side. This isnt a huge crisis for me though bc I plan on buying a whole new tire wheel set up for atuoX but I was wondering if anyone had any ideas about what could be going on or any simiar horror stories.

THANKS

 

sometimes they leak from the tire valve. had that happen once on another car and it took a while to figure out.

 

I have the same problem with one of my runflats. I have a slow leak, and if I don't add air every few weeks the pressure will eventually get low enough to set off the 'low pressure' indicator.
Like you, I plan get rid of my runflats. I already have a set of Hankook R-S2 tires (205/50-16), and I plan to purchase a set of Enkei RP-F1 wheels.

 

I had a slow leak on one of my old runflats. They did the dunk test and found a small leak at the bead. They remounted the tire and used some kind of sealent goop on the bead before hand. It was ok after that.

 

That sealant goop (depending on which brand they use) can cause major corrosion on the bead surface of your rim. On a steel wheel it can usually be wired off, but on aluminum it's not so clear on whether it ruined the rim. Sanding is the only way to tell if the pitting in the aluminum is bad enough. I wouldn't use the wire wheel on an aluminum rim.

 

I have different slow leaks in different tires. One time it'll be the front tires, next time the rear. About every 2 weeks, if I don't check the tires, the monitor will go off. My wife's '04 MC (still with the goodyear runflats until the Continentals come off backorder) hasn't had that problem. I'm wondering if it's the Dunlops.

 

Dunlop RF's here. One tire has had a slow leak for about a year, but it's getting worse. About twice a month I had to refill it, now almost weekly.

 

I had two tires with this problem. Seems the stock valves arent the greatest in the world. I went through a couple carwashes in the first couple years I owned my car and it seems that was likely the cause for the stems to go bad, besides their initial lack of quality. So check your stems and if you can, get em replaced, and then you should be fine....hopefully.

 

I bought my MCS with 17" wheels and the 205/47 R17 Goodyear Eagle RSA all-season runflats.

This past April, I was driving into Boston on the Turnpike and hit a gap in the pavement (they had resurfaced the road, but left this large gap at the end of the construction zone, between the new and old surfaces). I've never felt such a bone-jarring impact before or since, and I was only doing 45mph!

Two days later, my tire pressure light goes on. The impact had dented my left wheels, because the runflats' rigid sidewalls absorbed so little of the shock. What little shock was absorbed succeeded in deforming the sidewalls--even a small deformation amounts to a mortal wound for the runflats. The end result: $1400 to replace both wheels and tires.

I couldn't get reimbursed from the Turnpike Authority, because I couldn't prove that the gap in the pavement caused the damage (since two days elapsed before the light went on). I didn't use my insurance, because my premiums would have gone up for the next seven years, offsetting any benefit.

Damn.

I learned my lesson. I've now replaced my tires with 215/45 17 non-runflats. They're cheaper, they provide more cushioning and if they ever do get punctured, I'll know right away. That way, I'll be better able to prove the source of the damage for insurance purposes maybe avoid further painful costs.

 

Found my answer- nm.

 

I have a new 2007 mcs with run flats. the front passenger tire keeps losing air. 1200 miles 29psi (light)
1800 miles 30psi

 

I'm still finding that every week to two I need to add air, with one or the other tires (Dunlops that came on my R56 MCS on the 17" web-spokes) being low. It's been this way for a while. I see no evidence of any rim deformation, or tire damage.

The comment about the stems is interesting. Also the idea that shock could deform the sidewall.

I might take it in to a tire place and have that checked. No sense in driving all the way to the dealer for that, since if the wheels are deformed, that'll not be under warranty, and any warranty on the tires is with the tire manufacturer. And with 12K miles, I might just opt for new tires if they say the rims are OK.

 

It appeared that there was a leak around the bead of the tire. The leaky tire was remounted and there is no longer a leak I'm now at 5300mi.

 

When I had my R/Fs [Dunlop] they constantly leaked and the light would come on at least once a day. A real PITA!! Evan when they were properly inflated the stupid light would come on. Lived with them for 24K and now have B F Goodrich G force non-R/Fs. Problem solved!!