Can an overheating engine REALLY cause a fire?

Status
Not open for further replies.
Joined
Jan 29, 2014
Messages
723
Location
USA
Can an overheated engine really cause a fire like I heard? I always wondered. The only thing I could think of is if it melts wiring or a fuel line. Could someone please help?
 
I highly doubt it, if somehow the fuel leaked and the spark was caused outside the engine compartment, I don't see how an over heating engine can cause fire...

I personally have never seen melted wires or a bad fuel line either, I'm sure all of that is account for when engineering an engine/compartment
 
It's not the heat itself... it's what the heat does. Just like running an engine without oil makes it die from basically welding itself together, not the lack of oil itself. Unlike if you ran without gas, it's the lack of gas itself that would cause the engine to stop.
 
Overheating engine seizes, rod breaks and punches hole in block, oil leaks onto exhaust and catches fire...fire burns fuel hose... car burns to ground.
 
The kind of moron who'd keep going 10 miles with the gauge pegged and the car dinging at them is the kind who'd have a greasy, dirty engine catch fire.

If you manage to stick an injector open or just misfire from burning a valve or whatever all the raw fuel would super heat the catalytic converter. With pre-cats in the manifold you could really fry a turkey under the hood.
 
Originally Posted By: geeman789
Overheating engine seizes, rod breaks and punches hole in block, oil leaks onto exhaust and catches fire...fire burns fuel hose... car burns to ground.


Slippery slope argument.
 
Last edited:
oxygen, heat source, fuel source,,,yes , science says it will burn.

call your local fire-department
49.gif
 
Last edited:
Coolant, when concentrated enough, and sprayed on a hot surface, is very flammable. I saw it happen once, maybe 30 years ago. Stuck in a construction zone stop up, and the guy behind me was in a pickup with both a camper and pulling a trailer. Maybe 100 degrees out. While we were sitting waiting, he had his engine running. First there was a burst of steam, then smoke and flame!

I had a fire extinguisher and so did he.....It took both of them. When we got it out, and the hood up, the upper radiator hose had let go, and coolant was spraying onto the exhaust manifold. In conversation, he admitted he ran 100% coolant.

Before that, I used to run 60 to 70% coolant, so top ups would not be a problem. Since, I have been meticulous about keeping it at 50%.
 
Depends on the definition of overheating. 230 degrees wont do it. But yes in extreme situations, and a combination of events, it will catch. When I was younger, I would purposely redline engines till they blew before taking them to the junkyard (don't ask why) They will get so hot that the crankcase pressure escalates to a point where the PCV can flow enough, and it literally starts pushing oil out of the weakest link. Since the cylinder temps are very very high, and oil touches an exhaust manifold, many times it would ignite. A cherry red exhaust manifold would also radiate a certain level of "slight" flame that is sure to catch anything near it.

IMO a standard stuck thermostat, aware driver, shut down will not ignite an engine.
 
Originally Posted By: 4wheeldog
Coolant, when concentrated enough, and sprayed on a hot surface, is very flammable. I saw it happen once, maybe 30 years ago. Stuck in a construction zone stop up, and the guy behind me was in a pickup with both a camper and pulling a trailer. Maybe 100 degrees out. While we were sitting waiting, he had his engine running. First there was a burst of steam, then smoke and flame!

I had a fire extinguisher and so did he.....It took both of them. When we got it out, and the hood up, the upper radiator hose had let go, and coolant was spraying onto the exhaust manifold. In conversation, he admitted he ran 100% coolant.

Before that, I used to run 60 to 70% coolant, so top ups would not be a problem. Since, I have been meticulous about keeping it at 50%.



30 years ago would have probably been Ethylene glycol, which does have a flash point in the mid 230's. So that does make sense, straight coolant, hot manifold....
 
Even modern coolant is flammable. I was using some as a bead lub. When I set the bead with starting fluid, I had the stream of coolant catch fire.
 
Yes. Two years ago we had some bad ice and a driver in a late model 5 series was filmed on TV trying to drive on an icy street. He just sat there spinning his tires, overheated and caught fire.
 
Originally Posted By: Miller88
Ugh. That scares me. My Jeep is hemorrhaging oil.


need to put an engine diaper on that thing driver!
 
Originally Posted By: Avery4
Can an overheated engine really cause a fire like I heard? I always wondered. The only thing I could think of is if it melts wiring or a fuel line. Could someone please help?


I've seen it happen (and helped put it out). A friend had late 70s s Buick LeSabre that was his daily beater at the time (early 1990s). We were caravanning and his radiator cap was weak, so it pushed out a lot of coolant without him knowing it. Engine overheated, and the oil film buildup on the outside of the left cylinder head (from a slow valve cover leak) caught fire as he pulled off to the side of the road. I caught up to him a couple of minutes later and we got it put out before it caught any of the rubber or plastic parts, but it could have been a total loss if he hadn't pulled over when he did. We re-filled the radiator and limped him to a parts store for a new radiator cap. I think the car lasted another few years before he ditched it.
 
Since my car does not have a hood, I polish my engine every week, so oil buildup is not an issue. I fixed all fluid leaks.
 
Originally Posted By: camperbob
Originally Posted By: Miller88
Ugh. That scares me. My Jeep is hemorrhaging oil.


need to put an engine diaper on that thing driver!


I think so. I should start calling it puddles.
 
Status
Not open for further replies.
Back
Top