Massive Run Flat blowout yesterday

[HenryHank]

(not specifically a Z4 question... but would like to ask here anyway).

I was driving my g/f's newly acquired '09 335i Convertible yesterday.. We just got off the highway after about 2 hours at highway speeds. We were going straight on a local surface road, about 30 mph when all of a sudden, we heard what sounded like a gunshot nearby... it was so loud, we could hear it echoing off of the houses nearby. We had no idea what it was, until seconds later I could tell it was a blown RF tire, and we got an error message in the control display and then limped another mile to our destination.

My g/f just picked up this car on Wednesday, and it only has 15,000 miles on it.

What would cause a RFT to have a such a spectacular blowout like that? I've *never* heard a blowout like that before. This was *LOUD*! It was like the loud bang at then end of fireworks.

Anyway, we were stranded 120 miles from home yesterday, no BMW center was open yesterday or today, so we had AAA tow us back home last night for $140. (we didn't want to drive 120 miles at 50 mph with a blown tire, despite the published RFT specs)

LUCKILY, when my g/f bought the car, we opted for the 5 year BMW road hazard warranty. We didn't expect to need it in 4 days. We'll be taking the car to BMW tomorrow.

[Mayhem]

Don't know why you got a flat, but I honestly think you would have been fine just driving it home. They are going to have to replace the tire anyways. I've driven quite a ways on a flat when I had no choice.

[HenryHank]

Yeah, if I had just caught a nail, I don't think it would have caused such a loud and suddent blowout.

I know we could have driven back, but it was dark and raining in the NJ Turnpike, going 50mph in the right lane wouldn't have been the safest thing to do, and we did have the choice to get a flat bed tow home.

[Mr. ///M3 RD]

I have a hunch you experienced a tire malfunction that caused a blow out. Sidewall bulge or something of this nature. You can only be sure of this once the tire is examined by a knowledgeable tire shop employee/manager. They see all kinds of blow outs and you be wise to check with them, once you have there analyses/finding you can hit BMW for a replacement if it was a tire malfunction.

You can be glad that you have NOT driven back since that may have coma flashed the likely cause of the failure/blow out, you properly have a better chance finding out now what caused the failure/blow out.

Good luck geting it resolved.

[Dr Stig 2]

Any pictures of the damaged tyre?
Is it a hole, a tear, a rip or a separation from the rim?

I would rather not use this graphic as it looks a bit too aggressive, but its the only one we have available about needing photos... At least the smiley men are grinning.

[richard in NC]

I agree with others. A severe pothole impact by the previous owner, a bubble on the sidewall, over-inflation, and high speed running for a time could all contribute to the blow-out. It seems rare these days but the RFT did its job if she maintained control and continued driving.

I had a pothole incident that tore the sidewall in an RFT. Fortunately no blowout and the tire took 20 miles to loose pressure. Because of that, I feel RFTs are more susceptable to sidewall rips (due to the stiff inner core vs the outer rubber), but they do their job and keep you going (to a point).

[Otago]

I was getting heavy puncture by this long screw on my rear RFT on highway yesterday, no big sound but instrumental panel light up in sudden. RFT with me since i brought z4 (2 years and 9 months), may be it's time for me switch to non-rft.

[HenryHank]

Originally Posted by Dr Stig 2

Any pictures of the damaged tyre?
Is it a hole, a tear, a rip or a separation from the rim?

I would rather not use this graphic as it looks a bit too aggressive, but its the only one we have available about needing photos... At least the smiley men are grinning.

No problem, I use that icon all the time.

I would have posted pics if I could get any. There are no visible defects on the outside sidewall or tread. So the blowout must be on the inside sidewall, which I can't get to. I'll try to check it out tomorrow and see if I can get a pic.

[Dr Stig 2]

Originally Posted by Otago

I was getting heavy puncture by this long screw on my rear RFT on highway yesterday, no big sound but instrumental panel light up in sudden. RFT with me since i brought z4 (2 years and 9 months), may be it's time for me switch to non-rft.

Wow.

Over here, we call that particular type of screw, a bolt.

[Otago]

Originally Posted by Dr Stig 2

Wow.

Over here, we call that particular type of screw, a bolt.

Yes, U are right! A long bloody bolt, a pair of Michelline RFT cost me HK$8200 (US1,056.39 or AUD$1072.45), definitely switch to non-rft.

[HenryHank]

Here are some pics:

[juhap]

Originally Posted by HenryHank

Here are some pics:

Holy crap....that would've been "interesting" at highway speed.

[Otago]

Wow, totally shocked! That's one hell of serious blowout, thanks god u alive!

[HenryHank]

Originally Posted by Otago

Wow, totally shocked! That's one hell of serious blowout, thanks god u alive!

Yeah, luckily it happened only going 30mph on a surface road. But even at highway speeds, I would think the stiff sidewalls of the RFT would have done their job to maintain control of the car to pull over. But yeah, who knows what would have actually happened at 85mph!

[Dr Stig 2]

Originally Posted by HenryHank

Yeah, luckily it happened only going 30mph on a surface road. But even at highway speeds, I would think the stiff sidewalls of the RFT would have done their job to maintain control of the car to pull over. But yeah, who knows what would have actually happened at 85mph!

I dont think there is any stiffness left in that sidewall at all.
That is waaaaay beyond the damage you would expect a RFT woudl be able to cope with.
There is no way you would have been able to drive that the 120 miles home, at any speed.

[cdeslandes]

Was the proper tire mounted on the wheel?

Reason I'm asking is a friend of mine had a similar RFT blowout at 80 mph with his 328i; turns out the previous owner mounted the wrong size tire on the wheels...

[HenryHank]

Originally Posted by cdeslandes

Was the proper tire mounted on the wheel?

Reason I'm asking is a friend of mine had a similar RFT blowout at 80 mph with his 328i; turns out the previous owner mounted the wrong size tire on the wheels...

I don't know, but I'm pretty sure they are the original tires. We bought it from a BMW dealer, so if they were the wrong tires, I suspect they would have noticed something like that.

[richard in NC]

Just suposition but the left side of the tear looks like a weakened area (pothole, bubble, etc), and the long tear is similar to my RFT sidewall tear but mine didn't go all the way through.