Russ96GT

Driving my '96 Mustang GT home last week the engine cut out. I pulled over, opened hood, and saw smoke coming out of my air box (stock). I opened the clamp and about a 2" oval area near the bottom of the filter was charred black with red burning embers. I pulled the filter out and it basically burst into flames - seemingly from the inside of the filter. After getting rid of this filter, the car started properly and I was able to drive with just the open throttle body and mesh screen (although it ran a little rough). I must assume the engine cut out when the air temp sensor and/or the mass air sensor got consumed in smoke.

The good news is it was cheaper to replace with a K&N Fuel Injection Performance Kit instead of a stock air filter and box assembly.

Now the question for discussion. Is this an unexplained occurence for Ripley's Believe it or Not or is there some sort of reasonable explanation?

Here are the theories so far (*note I may not use proper terminology since I am almost a mechanical moron):

(1) A cigarette butt or ember bounced up through the air opening, into the intake hose, around the outside of the cylinder filter, burned through? This "could" be an possible explanation. I didn't closely look before the filter burst into flames, but did not notice any burning from the outside in.

(2) A short occurred that caused the engine to backfire (although I got no indication that this happened and the car has been running fine). This shot hot gas into the air filter and ignited it. My mechanic buddy says possible however he has never seen a backfire ignite a filter.

(3) Another mechanic buddy asked that I check the IAC and PVC hoses in the throttle body to see if any of them were right near the filter assembly. He assessed that something could have ignited in the engine and shot flames through one of these hoses to ignite the filte. None of these hoses were near the filter.

Any ideas? Suggetions? Has this happened to anyone else?

jeep45238

Cigarette butts are covered in ash, which is why if a cigarette is thrown at you it doesn't burn you. That and it doesn't pack enough energy to ignite the paper.

A backfire is a quick, hot flame, which if you've ever passed a peice of paper through a candel or match quickly it doesn't catch fire, the paper isn't given enough time to reach it's burning point, which takes even longer if it's thicker.

If flames went through the IAC or PCV system, your engine has some major problems.



Ripley's in my mind.

Russ96GT

Jeep...

I generally agree with your analysis. "If" (big if) a cigarette ember got sucked in and pressed between the plastic air box and filter, do you really believe it could not ignite the paper filter? I'm with you on the backfire and IAC or PVC flame as no major engine problems are apparent (although I have not hooked up and had the computer data analyzed).

Any other theories or ideas? I hate to say it but I would vote for the cigarette butt as the most likely senario at this point...

04ShakinSteed

Funny, I have heard of this before in this forum I believe. Same story, guys engine cuts out, pops the hood, fire in the air box. Goes to the gym located in close proximity and was going to put it out but was out by the time he got back.....Hummmm.

Don't buy the cigarette butt though.

Russ96GT

Steed,

Thanks for the input. I went back to the first of the year in postings and did not see anything regarding a burning filter. Do you happen to remember how long ago that posting was? Do you happen to remember if there was any solution to what caused the problem? I've got my K&N installed since then, I've been running hard and see no kind of engine problems. This is a mystery that I wish made some sense.

99 cobra

All i can say is that is messed up!


99 cobra

jeep45238

I really doubt a ciggarette ember could ignite a paper air filter. Ever see how long it takes to burn a hole through a peice of computer paper? Imagine trying to do that to some thick *** paper in an airstream moving fast enought to put the cigarette out. I don't buy that theory.

Snydaleid

Sounds like a job for the Myth Busters!

Russ96GT

Snydaleid,

Myth Busters? Trust me it was no myth when I was standing along the side of the road, air filter in flames, and some Georgia redneck chevy punks driving by yelling "Thats whatcha git fur buyin uh ford".

Nobody can explain the fire thus far, but the punks yelling was the worst part of the situation.

jeep45238

The myth busters is a show on discovery that disproves/proves urban legends.......