OK. Here’s what happened…

First off, my radiator filler cap thing that the coolant overflow tube connects to got all corroded. My line kept popping off the cap. So I made a little sleeve thing at work that was a little longer to put the line on again. Then I plugged the existing hole with a fat rivet and some aircraft sealant. It works wonderfully, except my radiator cap is kind of a pain in the butt to seat.

With this in mind… I was being a good little boy and checking all my fluids and topping off what was low. After checking my coolant level, I put the radiator cap back on but didn’t seat it properly, oops. So I went to Home Depot to get something, and of course being in a sweet little 7, I had to redline through every gear to show them cylinder boy’s what’s up. Long story shorter… the coolant doesn’t stay where it’s supposed to after the cap shoots off and sprays all over my engine. I didn’t really notice until I got to the Home Depot parking lot and smoke was leaking out of the right side of my hood. (It’s not that far from my house)

Pop the hood open and smoke just rolls out of the engine bay. First thought, OH ****. I didn’t realize I had this nice little 6” flame on the bottom of the engine (looked like something with the exhaust, I’m not sure) So I go runnin into Home Depot and told them I needed a fire extinguisher asap. “Aisle 10 sir” NO I need one now, my car is on fire in your parking lot. So of course they have to call the fire dept. So I get the fire out in no time because it was real small, the next thing I hear are sirens and see some fire trucks haulin through the parking lot. I told them what happened and all and they couldn’t believe coolant actually caught on fire.

So here’s the question… I’m guessing the coolant caught of fire because of the heat and it was all over the place, but you wouldn’t think it would, cause it passes through the engine and all. Anyone have an idea if it might have been something else? After that nice little embarrassment I have a new gooseneck on order and a little fire extinguisher in my car!

 

Ummmmmmmm, coolant catching on fire... somebody PLEASE tell me this isn't true...

Do you have a pulsation dampener?

 

straight coolent might burn (never tried it) but no way it going to burn when mixed 50/50 with water,.. i'd check your pulsation damphner.

 

If you get coolant hot enough, it will burn. Exhaust components are more than enough to light coolant on fire.

http://207.150.192.12/temp/crobert0/coolant.htm

And... you own a '7 and DON'T have a fire extinguisher in your car already? Shame on you!

Everyone else? A $20 fire extinguisher can save a LOT of money if you have to use it.

-=Russ=-

 

What do I need to check on the pulsation damper?

 

ive been a mechanic for 12 years and worked on about 13k cars in my lifetime, dropped all types of fluids on all parts of a car but never once have i seen coolant catch on fire.

slight coolant seal leaks could induce gas vapors/liquids into your cooling system which is probably what caught fire, not the coolant itself. the only thing that seals your combustion chamber from the coolant passages is a rubber o-ring, even under fairly normal circumstances i would say an average RX7 almost always has some fuel vapors in the cooling system.

 

www.rotaryresurrection.com ---> tech ---> 84-88 FPD replacement

 

Only if it is a S4 , then you check on the top of the fuel rail where it sticks out , it will be facing the radiator. There you will see a plastic cap , and under that cap is a tiny screw that will leak and then it will leak threw your plastic cap and onto your motor . I have had this happen on a road trip , I was lucky enough to get the screw back in and tighten it and it did'nt leak any more . Most people upgrade to the S5 type

 

or you can just remove it altogether and do the banjo bolt trick.

 

See 2 posts above yours.

 

it's late, i didn't feel like following links...

 

First of all, are you sure the bypass was still working to the overflow?
If not, you're going to get a build-up pressure that can damage cooling system components.
You really should not be trying to modify a crusty plastic component that can crack on you - replace stuff like that!

Mazda has officially pinned engine fires in the FD3S to coolant pooling on top of the engine and spontaneously combusting.
Regardless of your background, Mazda has confirmed that coolant can catch on fire.
Please, don't argue with me - argue with Mazda.

It really sound suspiciously like a PD fire.
Did you smell gasoline before the fire?
The gasoline fumes are rather obvious, especially if you have to pop the hood.


-Ted

 

I'm sorry, but this has been a myth perpetuated for a long time now.
If the PD is going to leak, it's going to leak through a damaged diaphram.
The screw is nothing more than to keep the diaphram centered.
In fact, overtightening the screw can cause more damage that can increase the chance of fuel leaking!
If the screw falls out, don't attempt to put it back!


-Ted