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Jeep caught on fire...

DanMan2k06

NAXJA Forum User
Location
Damascus, MD
If you think the whole "oil igniting on exhaust" concept is just a myth - think again.

It was about 2am, some buddies and I were at the beach and decided to go bomb some dunes. We got to the sand, and started playing around. I'd say I was around 60-70% lead foot status. Pushing her, but definitely not to the limit. My temperature gauge climbed to about 220, and stayed steady so we continued. This all happened within about 15 minutes. Next thing you know, I smell something that resembled burning crayons. I came to a stop, and my buddy says "dude what's this light on the ground from?". We both jump out and find the underside of my rig in flames. Particularly the bell housing/pan area, and the downpipe in front of the crossmember. Luckily I had a gallon of drinking water in the back, and we were able to put it out before any damage was done.

Trans fluid was overflowing (gratuitously) from the dipstick, dripping down it, and pouring onto my downpipe. I couldn't believe how quickly is was igniting either. As soon as it hit the pipe, it would burst into flames.

So this begs the questions: what the hell caused the fluid to erupt out of the dipstick? I also noticed a puddle on top of my intake manifold, right beneath the TV cable. Almost like the fluid had climbed up the jacket off the cable and spewed out. Could my vent be clogged? ABSURD heat (gauge inaccurate)? Too much fluid? I will also note, that once it cooled down, we drove back home without issue. Checked it again at the house (in neutral, hot, at idle) and it was dead on the mark. Then proceeded to drive 325 miles back to MD, again without issue.

Any ideas??
 
overheated the transmission, it happens pretty easy in sand because there is a lot of drag put on the tires and not enough speed to make the radiator's internal trans cooler work worth a crap. there is an overflow above the starter that starts to spew first but if it gets bad it will come out the dipstick tube as it boils over, not sure why you found it on the intake that's a new one to me.

you're lucky, burning ATF is one of the most common causes of desert rigs burning to the ground as oil fires are usually very hard to put out.
 
Overheated the transmission. Engine coolant temp is a poor indicator of transmission temp. You need an external transmission cooler and a transmission temp gauge wouldn't be a bad idea. You will also want to change out the transmission fluid.
 
As others have stated, the transmission fluid got hot. Transmission fluid expands rapidly when hot, and can easily gain a pint or more in volume.
If it can't make it out the vent hole, it will find other places to come out.

So... Follow the directions on the dipstick when refilling the transmission. The level should be full when HOT and in neutral. Filling to the full level when Cold will guarantee a spill over when the tranny is overworked.
 
Your next purchase for you rig. A correctly rated fire extinguisher. You where lucky the water put out the fire as well we all know oil and water do not mix well. And if hitting the dunes again I would install a trans temp gauge just in case....
 
Your next purchase for you rig. A correctly rated fire extinguisher. You where lucky the water put out the fire as well we all know oil and water do not mix well. And if hitting the dunes again I would install a trans temp gauge just in case....

I agree on the extinguisher. During a trail clean up a couple years ago we had a rig's tranny line blow and the ATF caught fire and burnt through a fuel line. Luckily we got the rig shut down and the fire put out before it burnt to the ground. Only minor things needed repaired.
 
So... Follow the directions on the dipstick when refilling the transmission. The level should be full when HOT and in neutral. Filling to the full level when Cold will guarantee a spill over when the tranny is overworked.

Checked it again at the house (in neutral, hot, at idle) and it was dead on the mark.

Fire extinguisher is definitely on the immediate to-do list. I was thinking to myself, while throwing sand at the exhaust under gut reaction "WHY THE F DON'T I CARRY ONE OF THOSE".

Grimm I seem to remember you had a fairly extensive thread on replacing the trans lines with AN fittings and a judiciously sized trans cooler. Is everything still leak free? My lines are seeping a fair bit, so I think a full work-over of the system is in order.
 
sucks man. glad to hear yours is going to be alright though. mines seen better days lol

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mostly general jackassery

Ok I lulz'd at that one.

Immediately after the incident we kinda laughed about it, and let the car sit on the beach for an hour or so. I had a case in the back so we cracked open a few and joked around before driving back to the house (a mile away). After thinking about it for a while, and what it would be like to NOT have my jeep sitting in the driveway, I'm extremely grateful that it was just a small event and I didn't have to witness 2 years of work and gobs of money burn to the ground.

Talyn I've never seen something like what you linked, I'm a little confused? Does it spray it's content in multiple locations where you mount the nozzles?
 
Talyn I've never seen something like what you linked, I'm a little confused? Does it spray it's content in multiple locations where you mount the nozzles?
Depending on the kit they have different number of nozzles. From the brief research I have done the most common count is 3. The tank is activated by a pull or push cable. Since you want to spray the engine bay it might be possible to mount the tank far up in the passenger foot well. Speculation of course because i don't have one. The next question is placement of the nozzles. I'm thinking one on the driver's side engine bay, one on the passenger side bay and one maybe behind the valve cover or above the transmission. I would put the pull on the right hand side of the underside of the driver's dash so no one would confuse with a hood release. I know a lot of race vehicles us a similar system. Also, being Halon or some derivative it won't hurt wires, electronics or connectors.
 
Hmm very cool. A little zealous for the sparse wheeling that I do, but looks very effective.

What is a normal size extinguisher for our scene? I've only ever use 2 - One at home that was smaller than a spray paint can, and lasted close to 2 seconds. And one at work, which was pretty diesel. I felt like I could spray that sucker for days. But it also weighed about 30lbs and was taller than my knees.

I'd like something adequate, but as always, as light as possible.
 
Hmm very cool. A little zealous for the sparse wheeling that I do, but looks very effective.
I wouldn't use that for a gauge if you need a system like that or not. A fire can start for any number of reasons, not just an overheated transmission that caught the fluid on fire. Fuel injector leak, fuel intector o-ring leak, oil leak, over heated exhaust. electronic fire, battery explosion, ect are all good sourced of fire. All of which could happen for any number of reasons, even when not pushing it. It boils down to how irreplaceable/how much you have in your XJ.
 
Originally Posted by WB9YZU
So... Follow the directions on the dipstick when refilling the transmission. The level should be full when HOT and in neutral. Filling to the full level when Cold will guarantee a spill over when the tranny is overworked.
Checked it again at the house (in neutral, hot, at idle) and it was dead on the mark.

Yah, after you puked out all the extra fluid on the Beach ;)

An extinguisher is a good idea, some areas mandate them, but the Halon system is a bit overkill for a DD/Trail rig. Besides, no-one uses Halon systems anymore, they are eco-taboo and will kill you dead in a confined space. Carry a 2-3lb ABC and you should be ready for most any material fire the XJ will throw at you.
 
You can still get Halon or Halguard, which won't damage electronics. And when are you driving in a confined space?

ABCs are corrosive so after you save the jeep from fire you may be replacing any wiring or electronic component it came into contact with. Besides if you are close enough to breath Halon you are close enough to breath ABC.
 
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ABCs aren't all that bad if you hose the residue off quickly. If you let it get stuck to stuff it makes a hell of a mess.

I carry a 10lb in the jeep and have been considering adding a 5lb on the driver A-pillar. You want them within easy reach even if you're in the seat and belted in.

ATF ignites VERY easily, especially on the exhaust. Motor oil is a lot harder to get started. Before I rerouted my cooler lines from the passenger side oil pan mounting flange (stock location) I managed to smash one of them flat with the UCA and it punctured the line in the process, shooting a fine stream directly onto the downpipe. That was a bit more excitement than I wanted when my spotter was like "hey dude... your jeep is shooting fire. Might want to shut it off." I don't think I've ever grabbed the extinguisher, jumped out, and run around the jeep so quickly in my life.
 
Fire extinguisher is definitely on the immediate to-do list. I was thinking to myself, while throwing sand at the exhaust under gut reaction "WHY THE F DON'T I CARRY ONE OF THOSE".

Grimm I seem to remember you had a fairly extensive thread on replacing the trans lines with AN fittings and a judiciously sized trans cooler. Is everything still leak free? My lines are seeping a fair bit, so I think a full work-over of the system is in order.

i sold the trans and converted to an ax15 but the new owner is still leak free as are the others that have done the conversion that I know. it's worth it to do the changeover, as you've seen now ATF is extremely flammable.
 
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