jimhsu

My wife's 996 4S rear driver's side tire goes flat slowly. Has done that twice now. I took the car to the place that installs my Tirerack.com purchases (an approved installer, but did not do the job for this car), and they took the wheel off and dunked it in the water tank, and as I watched: no leak spotted. He dismounted the tire from the wheel, we looked on the outside and the inside of the tire, and saw nothing. He then put a new valve stem on it: fine for about one week and now it's going flat again.

The tire is whatever is the stock replacement for the 2004 4S; Michelin Pilot Sport I think. (I am not at home to check it right now). It was installed in N. Carolina new @ 2 months ago as part of the fix-ups before I bought the car from a private seller, and it was installed at Hendricks Porsche. We are in Seattle or I would take it right back to them.

Should I put a can of Fix-A-Flat to the wheel? Has fixed my Camry slow leak before, but I'm not sure if I want all that goop in the wheel.

In this situation, if Fix-A-Flat is not helpful or not recommended, should I take it to the local Porsche dealer since it was installed at a dealer in NC? Or is it Michelin's warranty? If so the local Tirerack approved installer should be able to help with any warranty work, right?

Thank you for your help!!

fpena944

I know on the can itself fix-a-flat is not recommended for Z or N rated tires. Not sure why but it might be because of the heat that builds up within the tire and the fact that the stuff is flammable.

Might be best to take it to an expert. I had the same problem on a set of tires for my 944 and could never find the source of the leak even after taking it to two tires shops. Fortunately I moved to another set of tires/rims shortly thereafter and never encountered the problem again.

Jim Griffin

I had a slow leak on my C4S rear tire and they could not find the leak in the tire. However a very experienced tire man took one look and saw that I had chrome rims on the car. He took off the tire and found a small amount of chrome that had built up on the rim edge. He filed it off and now, no problem.

1999Porsche911

In 9 out of 10 cases, fix-a-flat will be a permanent fix for small (nail size) leaks and will last for as long as the tire does. Leaks in tread only. Not side wall.

C4CRNA

Look more carfully at the rim where the tire bead is. Take tire off lay flat and put soapy water on bead area do both sides.Look for very faint fizzing in this area.

brad@tirerack.com

I agree. I have seen it all in terms of wheel leaks. Even air that goes through channels in the alloy. It's leaking somewhere, and it's probably from the bead.

As far as fix-a-flat goes, the biggest reason we don't like it is the fact that it's chemical based and once it's in you are not getting it off. It can ETCH itslf into the alloy on your wheels and cause corrosion related issues in the future. TPMS sensors? Yeah, they USED to work.....Another problem is the false security it provides by "filling" your tires up as it seals. No it doesn't, it just adds a few pounds to get you home. Too many people think it adds sufficient pressure to the tire and never add more. Many times the tire is damaged as a result. Remeber, 15 lbs in a tire can look like 35 even though it's far from it.

Take a look at the Continental Comfort Kit we sell:

http://www.tirerack.com/accessories/...Tire+Inflation

It's water based so won't hurt your wheels or tires, re-fillable, and inflates your tires back to OE spec. It will seal up to 1/4" as well. It's good enough that Ford used it as OE on the GT. Every trunk on them has one.

ivangene

I vote NO for fix a flat - find the leak

Edgy01

That stuff will fix it,--but am surprized when you say it shouldn't be used on Z or N rated tires. Guys,--that's what Porsche packs in the trunk of these cars now (997) in lieu of a spare tire. It will work,--have used it on a variety of slow leaks on wheelbarrow wheels, tractor wheels, and cars. Don't sweat the mess inside. Tire repair shops have seen this stuff before and can deal with it.

ivangene

ok correct me if I am wrong:

when this "stuff" seals the tire - there is really very little of what you actually put in the tire used to seal the tiny hole - right ?

SO

where is the rest of what was injected into the tire - it either hardens / or it stays a liquid. I have seen both (back in the day) and in my opinion having liquid inside at 100+ mph would cause tire to be out of ballance? or does it "self ballance" with liquid..... if so, why dont tire shops just use liquid to ballance our tires?

If it hardens then you have a "lump" of this stuff somewhere and I am guessing the ballance thing comes up again.

Third is the stuff IS a mess... when you remove the tire its a big mess... I still vote no - just my .02

Tippy

Every time I have used the crap, my tire ended up going flat before reaching my destination.

jimhsu

I posted yesterday before getting home. Sure enough, this time I looked at the tire and there was the head of a nail on the thread.

I will take the car in after pumping it up (only 3 minutes away). The head of the nail looks to be @ 4mm dia. I have no idea how big the shaft of the nail is. Should I go ahead and order a driver's side rear tire if it is not fixable? Otherwise I will be stuck there without a tire, right?

wross996tt

First I would never use the tire place you use again...if they can't find the nail in the tread they are worthless. You can patch the hole...

medtech

Patch it!

jimhsu

I can't blame them. I was there the whole time watching and examining the tire myself with them. We dismounted the tire and looked at it from the inside, and saw nothing protruding. I don't think I have a big enough blind spot to miss a big protruding nail that day. That's why I think this nail may be new.

I was thinking we could prob. patch the tire given that the nail is on the deep, thick, raised part of the tread. It is close to the edge but not on the side wall.

C4CRNA

Porsche may put the fix a flat stuff in the 997 trunk,
they will also tell you not to repair an n or z rated tire

I would patch it myself,the autobaun and it's speeds are pretty far from here.