Flat Tire - A First Time for Everything

Yes, it's true - in my over 20 years of driving I've never had a flat tire. Until just last week, when on the way home from Yokota Air Base, my Chinese made "RUPSE" Tire Pressure Monitor System started going bananas.  In the past, on a hot day it had indicated a problem, but when I parked the car and drove on a cooler day, it was fine.

So when the TPMS started flashing again indicating a fault in the right rear tire, luckily I was going slow enough to pull over and take a look. The right rear tire looked fine, but just in case I looked at the other rear tire and... yep it was pretty flat (the sensors had been switched left to right on installation. Oh well). Tire gauge indicated a 1.5 when all other tires were 2.5.

As I was hoping for a slow leak, I pulled into a gas station, had the tire inflated back up to 2.5, and then drove home. The TPMS warning went away, but then as I approached my house I noticed the air pressure number for the right rear (in reality the left rear) tire dropping. And of course, the next morning the the tire was flat with the rim on the ground, with only the rubber of the tire between it and the ground.

So I went off to work, and during the day called the dealer to see if they could help. Their idea was, with a slow leak I could either inflate the tire myself (or mount the spare) and then drive over, and they would see if they could repair the tire. So that's exactly what I did - I left work early, used a portable electric pump and filled up the tire, and drove to the Lexus dealer, thankfully only about 1.3 km away from my house.

After enjoying the free drink and snack, they invited me back to the workshop to check out what was going on.

Super clean, wish the Nissan dealer was like this too...

 Surprisingly, they found a nail in the tire, but that wasn't the cause of the leak. When they dunked the tire in soapy water, they found the source of the leak.

Looks like something wedged in there. 

 Luckily, because it wasn't on the side of the tire, it was repairable.

But look at what it was!

Broken off knife blade!

It appeared to be a broken off utility knife blade.  So they plugged up the leak and told me it was a temporary fix, and sent me on my way.

Now, I DID ask about what tires to get next - the car is on Michelin Pilot Super Sports, and while those are still in stock, for not much more I could get the Michelin Pilot Sport 4S, which is the follow on model to the Super Sports. Unfortunately, the dealer wanted about 80,000 yen per tire (or about $800 each!) while I could shop online and get each tire for less than half that price. So guess what I'll be doing soon...

Except of course I have other expenses in my life right now, so as long as this repaired tire holds (the dealer showed me I have about 4mm of tread life left until each tire hits the wear bars on the tire), I'm going to try to hold out...