Porsche Supplied Tire Sealant is Worthless

Ask me how I know. Even after waiting an hour or so for a tow truck, the river of liquid sealant flowing out of my tire was still liquid. It never solidified. During that wait, I used the compressor once or twice, and all that resulted was a hair spray like spray of sealant coming out of the SMALL hole in the tire. This was after I had driven a short amount with the sealant in the tire. Driving is supposed to seal it. No luck there. All it did was fling up into the wheel well, for both the front and rear tires , as the rear drove over the sealant leaking out of the front tire. I put the sealant in the tire by the side of the freeway (a big pull out area, so no safety worries). I happened to notice the TPMS readout showing one tire 3 or 4 pounds less than it should, so I kept in an eye on it. Sure enough, it was dropping slowly, 36....35....34, so I pulled over. By this time whatever caused the hole was long gone and I could hear the hiss. Time for the sealant. I got the sealant in and used the compressor to get the tire up to about 40lbs and quickly got back on the freeway. The pressure was dropping fast, so fast all I could do was take the very next exit. Luckily there was a gas station there, where the sealant poured out. 5 hours later, a tow courtesy of Porsche Roadside Assistance, and a patch, I'm good to go. No concerns about the sealant ruining the sensor or cleaning out the tire or anything. No rim damage (thanks to stiff sidewalls!), so all in all not much harm done. The tow truck driver said the product called "slime" has little bits of rubber in it that help seal holes. I'll get a bottle of this and a plug kit. I don't know why Porsche doesn't supply plug kits, I suppose due to the difficulty in getting the plug in the tire. I did some searches on this forum for these topics and it seems plugs are the preferable choice. I'll also put a couple big garbage bags in the car. These fold up real small and are good to throw on the pavement when you have to reach under the car. I'm also considering a spare. My problem occurred at 7:30 AM on a Sunday. Nothing was open at that time, even local tire shops. A spare (or plug kit) would have gotten me home, where I could then deal with the issue at my convenience.

Sounds like a bit of an ordeal . . . I think yours is the first report I've seen (at least on this forum) of someone actually trying to use the stuff. How big was, or what made the puncture hole? Was it through a tread or groove area on the tire? I believe the tire goop is supposed to be replaced every 4 years, so I wonder if it loses its performance over time; however, since your car is a 2008, that shouldn't have been an issue. I keep a Tire Slime kit in our other car - maybe I need to keep one in the Cayman also.

I never saw the object that made the hole. The hole was consistent with a nail or nail like object. Surrounding the hole was an indentation consistent with a nail head. The hole was smack in the middle of a tread block. It was certainly the kind and size of hole I would expect the sealant to be able to handle. The sealant never solidified. I think that is the issue, not the size of the hole. Well over an hour after I put the sealant in, it had the consistency of whole milk. The build date on my car is early 2008, so even if the goo dates to 2007, it's well within the four year window.

Same here... Sidewall gash, no point even trying the goop... I waited for the truck for almost 2 hours.... And promptly bought a 986 spare which resides in my front trunk now !

For simple punctures, I would recommend the Dynaplug system for self-rescue. I will not debate the longterm merits of plugging vs replacing a tire.......please! But, to get you home, the Dynaplug works great. I use it on my Goldwing and my Cayman . You can get them at Harbor Freight .

There was a discussion about this issue (probably many) some time back and what I came down with as a way to be prepared for a flat was to carry a jack, a rope type patch kit, lugnut wrench, and needle nose pliers. There was agreement that the slime would ruin the TPMS sensors , I guess you were lucky. Jack the car up, remove the wheel, remove the (nail?) with the pliers, plug the hole with the patch kit, pump up the tire with the Porsche electric pump, reinstall tire, drive off. If you get a gash in the side wall, you're toast. That happened to me once in 55 years of driving. Every other flat was fixed with a rope patch kit. They have worked every time, first time. That will get you home.

Smart man Deschodt. No substitute for a tire. I have the following in my truck. A few pairs of latex gloves A few plastic trash bags A tire repair kit (plugs) A Viair model 85P (I keep the toy that comes with Porsche , under the work bench. I threw out that gooey/goofy stuff) A few reflectors A few flares A medical kit

People always say "I'm going to go get a spare tire". To that, I respond, "Where are you going to put the 18" or 19" wheel with tire on it once you've pulled it off? The flat tire and wheel won't fit in either of the trunks. Better hope you're driving alone when it happens so you can put the wheel and tire on the passenger seat--and make sure you have a clean bag that'll fit over the tire.

Purple Bubblicious Bubble gum :hilarious:

Carry a couple of bungee cords too . . . Check out Babbo's well thought-out plan here: Mounting a Spare and Transporting a Flat - Articles

Well, I bought a 16 oz bottle of "Slime." The bottle claims it is tire sensor safe, non-toxic, and cleans up easily. It also claims it can plug a hole as big as 1/4". I'm not sure I buy that last claim. 1/4" seems pretty big. I also bought a plug kit that has big pistol grips for the two tools: the reamer and the plug inserter. That should make inserting the plug fairly straight forward. Roll the car until you have access to the hole, lay down, and have at it. Both items easily fit in one of the little storage bins in the rear compartment. I would recommend the same to owners of any car without a spare. If you get a flat in the middle of the night, or even 7:30 AM on a Sunday when everything is closed, you're toast. Hopefully the plug kit and Slime will fix just about anything except a major blowout or tear in the sidewall or something. I'm still considering a spare, despite the lack of a good place to put the original wheel. The only thing I can think of is to put it in a big garbage bag and put it on the passenger seat. Of course, if you have a passenger, well, hide it in the bushes by the road and come back for it later (hide the tire! Not the passenger!).

Assuming I had room in the rear trunk, and it wasn't pouring rain, I would just bungee or tie down the rear hatch as much as possible (use some padding between the hatch and flat tire), and drive with it slightly open if necessary. That's why I carry a couple of bungee cords with my spare.

After you get past the power, braking and handling (admittedly important attributes), Porsche "engineering" really falls down on this kind of stuff. Whether it's the lack of a spare, the difficulty in accessing the battery if it goes dead, the need to access the engine from underneath or other nutty things, Porsche seems to be saying to its owners: :taunt:.