[SM335i]

Hey guys, so I was drifting with some friends on a plaza and my friend noticed that my car was on fire, I got out and saw flames that were coming from what looked like underneath the turbos. My car has aftermarket downpipes. I got super scared and we started throwing snow on it and put it out pretty quickly. I turned it off and let it sit and cool down, then I started it up and everything is fine, no check engine light, no leaks, nothing... My question is what could it be? The oxygen sensor wires are totally fine and all the little rubber tube protectors are fine too... Any idea what it could have been? I think that the gasket after the downpipes is busted and the car got pretty hot maybe some flames seeped through and caught the plastic under tray on fire? I also saw a bunch of oil residue near the downpipes..

Also, drove home another 30 mins and no problems. I feel like if something serious caught fire, or some fluid, we wouldn't be able to put it out with just snow. I didnt use much brakes either, so they couldn't overheat..

[MTTH]

Wow, scary stuff. Glad everyone's okay!

[VTECaddict]

Get it on a lift and see where the damage is.

[SM335i]

Can oil catch fire like that?

[Opo]

My 2008 e90 335i caught fire leaving my driveway just over a year ago. I couldn't put it out in time so it was written off. But the fire seemed to have started in the same area of the engine bay you're describing. Damage was too extreme on mine to tell where exactly it started but I now carry a fire extinguisher in the trunk of my 2007 e92 335i

[Socket]

You were super lucky dude ... go buy a lottery ticket

[Blaster400]

Are you using meth?

Originally Posted by SM335i

Can oil catch fire like that?

lol oil? flammable? NEV3R!!

[Cloud9blue]

Get it on a lift and see where it started. My guess is that you caught something in your undertray and that started the fire by rubbing on the super hot down pipes or exhaust manifold.

[pinky_and_me]

If your windshield washer fluid has a decent amount of ethanol in it then that could have spilled from the cap and down the tray.
When the WW meth kits were catching fire I saw few people post that BMW changed the washer fluid cap to make it less prone to open while driving.

[deeLow]

Originally Posted by pinky_and_me

If your windshield washer fluid has a decent amount of ethanol in it then that could have spilled from the cap and down the tray.
When the WW meth kits were catching fire I saw few people post that BMW changed the washer fluid cap to make it less prone to open while driving.

Any word on that new cap? My stupid cap pops open very easily and I'm afraid of this exact thing happening.

[ucdbiendog]

Originally Posted by deeLow

Any word on that new cap? My stupid cap pops open very easily and I'm afraid of this exact thing happening.

+1. seems every time i open the hood that thing is open.

[335NJ]

My guess is the revs were high for a long period of time which super heated the downpipes, and that oil residue or any other flammable liquid that was down there just went up. Drifting around or even driving at a high speed would mean there's a lot of oxygen and air in the bay to make the heat to air mixture more suitable. Just a guess, but hopefully it doesn't happen again!

[catcher22]

Originally Posted by 335NJ

My guess is the revs were high for a long period of time which super heated the downpipes, and that oil residue or any other flammable liquid that was down there just went up. Drifting around or even driving at a high speed would mean there's a lot of oxygen and air in the bay to make the heat to air mixture more suitable. Just a guess, but hopefully it doesn't happen again!

+1

[Jklad]

Glad everyone's ok! There's been times when I wished mine would go up in flames lol!

[mike@x-ph.com]

Glad to hear no one got hurt

[SM335i]

When I popped the hood, the first thing I noticed was that cap for windshield washer fluid was open. And no I'm not running any meth

[SM335i]

Don't have access to lift, so I'm going to get it on some ramps and see what's up

Thanks guys

[SM335i]

Update: So I was under the car for 30 minutes trying to find anything that looked out of ordinary and did not find much. The rubber hoses and wires seemed fine, all the plastic trays are perfect, no burns, no melting spots. All the rubber bushings are in normal condition. The only thing that looked odd was residue on the downpipes near the gaskets following the downpipes and also same residue on the rest of the downpipes. Looked like fire corrosion residue or something. Gaskets are toast, but they were already done prior.. Saw oil residue around the turbos, but looked same from last time I checked. Nothing leaking either..

[Jeff@TopGearSolutions]

Originally Posted by pinky_and_me

If your windshield washer fluid has a decent amount of ethanol in it then that could have spilled from the cap and down the tray.
When the WW meth kits were catching fire I saw few people post that BMW changed the washer fluid cap to make it less prone to open while driving.

Originally Posted by deeLow

Any word on that new cap? My stupid cap pops open very easily and I'm afraid of this exact thing happening.

Originally Posted by ucdbiendog

+1. seems every time i open the hood that thing is open.

BMW did redesign the cap and it now has a fire symbol on it. You could probably pick a new one up at the dealer and I highly recommend everyone does, at a minimum.

Honestly, I never used my WW fluid as I clean my car once a week, I'd sooner tell you all to leave it empty if it wasn't for the low fluid level light.

My suggestion would to be to put 99% water with a dash of alcohol or methanol so it doesn't freeze. BMW should recall the entire WW reservoir as it's a fire hazard.

As far as the OP, I'm thinking unburnt fuel or oil leaked out of the downpipes and caught fire, that's my only guess.

[gzim335]

theres no way any ww fluid will catch fire,my car caught fire due to the old caps it opened while sliding/drifting but i had 100% methanol n slightly overfilled.

[Jeff@TopGearSolutions]

Originally Posted by gzim335

theres no way any ww fluid will catch fire,my car caught fire due to the old caps it opened while sliding/drifting but i had 100% methanol n slightly overfilled.

Depends on the concentration of fluid and how bad your luck is. Believe it or not, people with stock fluid have gone up, I actually know of a few. The stock reservoir is also just as suspectible to leaking over time as the car ages and seals begin to corrode and leak. Those leaks typically end up in the undertray and when they get sloshed around the vapors go up from the high concentration of heat by the downpipes and turbo's.

Why do you think BMW redesigned their WW cap and put a flame symbol on it? I can assure you it's no coincidence.

There is also WW fluid available over the counter with up to 40% methanol which is strong enough to go up in flames.