Hi there,

Background: Have had my MCS since October 7th. Have around 5500 (?) miles on it. Have not checked the tire pressure since I first got in it.

Yesterday I drove into my garage and noticed that the low tire pressure light was on. I checked the pressure and all were ok except for the front right which was around 20lbs low. Here are my questions:
1. Is it possible for a tire to lose that much pressure without having puncture?
2. With run flats, is there an obvious difference between a low pressure tire and a flat?

My plan at this point is to fill the tire with air, reset the light and then see what happens. (Hoping that it's not a puncture.) Is this a good plan or should I be doing something else?

Thanks for your help!

Laurie

 

Laurie,

I have about 11k miles on my MCS. My pressure alert has gone off twice. The first time I actually had a nail in the sidewall of a tire and had to replace it. The second time there wasn't any intrusion, and not even a big difference in pressures among my tires. I reset and it's been weeks now and no problem. My understanding is the the gauge actually measures a difference in rotational speed, not actual pressure. Thus, you don't have to have some type of puncture or intrusion. It might be a valve not being tight, etc.. I think seeing what happens now that you have pumped-up the tire is a good idea. You might test the valve by putting some saliva on it with the cap off to see if it bubbles. You might not see a big difference when you have a flat...mine looked about the same. Last thought is that your bead might have been off and now is seated again...or is still off if you are still losing pressure.

Best of luck.

 

I had a similar problem with both my set of tires (all season run flats and Yoko summer tires). One of the tires just seemed to keep going down about 15 to 20 pounds over a period of two weeks. I would take the car into a tire shop to look for leak and they would find nothing. Finally a guy at a non-franchise tire shop said that on low profile tires the beads don't seat up all the way sometimes. He suggested over-inflating the tires (50 pounds) for a while. Sure enough, that fixed the problem.

 

The simple answer is…
Yes it is possible to loose that much pressure and not have a puncture in the tire. Just reset the warning light and check the tire for a couple days, you’ll know if you have a flat.

 

I've filled up the tire and reset the sensor and all is good so far! Now, I'm out to run around some parking lots, first time in the MINI on snow. WOOOO HEEEEEE!!!