what could cause a engine fire

[steveo412]

hey guys,i bought this 1995 seville sts cheap,it started or the most damage is on the firewall,the guy said it was runing when i made it home and noticed a black smoke coming out from the engine,he said he shut it off and grab a fire extinguisher and put it out,the damage i see is all the plasic on the firewall,i looked down to see the back o2 sensor and it still had good wires on it,there is alot of wires coiled up and run along the wall,it looks like about 4 inches near the pasenger side up close to the pcm wires that go into the car,that seems the worest,could wires just catch on fire raped up like that,or does it take a wire on hot parts to start a fire? i already have the engine wiring harness out of my 94 eldo,- the injector wires,,i took 3 or 4 relays out and 2 differt fuse boxs under the hood,,and my pcm,,,,,there is wires that run into the drivers side,i didnt touch them,,there good on the 95 seville,,, i did notice that the wires that go into the abs dont look the same,but i didnt take the cover off,but its a whole dirffernt set up,,,any clues?

[BodybyFisher]

how does the muffler system sound?

Are the O2 sensors in place?

Black smoke coming from the rear bank down low? Oil fire? what does it smell like oil or electrical?

[BodybyFisher]

Did you buy a factory service manual yet?

[Ranger]

what could cause a engine fire

There was a fuel rail recall for the '95 - '97's. If yours was done it should have a stainless steel fuel rail. If not, that may be the cause of the fire.

[BodybyFisher]

what could cause a engine fire

There was a fuel rail recall for the '95 - '97's. If yours was done it should have a stainless steel fuel rail. If not, that may be the cause of the fire.

Good point, I had forgotten that the rail could still be a problem

[Cadillac Jim]

It sounds more to me like someone did a wiring harness repair and left a lot of extra wire bundled up where it laid against the exhaust manifold.

[hjb981]

... could wires just catch on fire raped up like that,or does it take a wire on hot parts to start a fire? ...

A shorted wire could definitely start a fire. It does not need to touch any hot engine parts to do that. It would get hot all by itself by from the electrical current. Normally a fuse should blow if there is a short circuit, which would prevent a fire, but if someone has bypassed a fuse or there is another way for current to go through a wire without a fuse in series, it could get hot enough to start a fire.

[steveo412]

the o2 sensor is in place with wire sticking out of them,i think jim is right tho,because it looks elecrical,on the top bank of the firewall the wires are burnt in 4 to 6 inch spot and it seems to burnt everything around that was plasic, maybe the heat?,i have pic but there not good due to crapy camera,i just found out the abs wires are not the same,im thinking just take out mine and put it in the 95,will that work?yes i have the manual but its for the eldo which is a 94,the intake cover are different on the 95 seville,not like mine ,where u had to torch it down,the 95 is 4 screws and yes it has the stainless rails,the injector wires are untouched bye the fire,and are on different wiring,im still going to keep them on the car,

[steveo412]

well the 1995 seville is a one year wiring harness,,225 shipped,,,,

[stsbank]

Is that a plastic fuel rail on the picture?

[Ranger]

I couldn't tell.

[steveo412]

nope its a stainless steel rail,i know the pic looks bad,what your seeing is the plasic pvc that goes to the valve cover,i did order the right harness,its funny cause everything matched up but the abs,i got the old harness out,i think the fire is wire related,im seeing wires melted that arnt even close to the fire damage,so maybe thay got so red it just started to melt different places in the harness,,im going to switch out the o2 sensor just to be safe,the nice thing is that the fire just melted the pcm harness to the fuse box,because the other harness would be a pain,dont get me wrong the main engine harness took me 3 days to get out,due to the engine being in the car,,the tuffest was the speed sensor under the wheel well,also the knock sensor,the other good think is that the fuel injectors and starter wires are fine,but it did melt the top cover a bit,i think when he had the block drilled thay were careless on puting wires in the right holders when thay put it back together

[steveo412]

[steveo412]

ok i got harness out,the worst part of the harness is right bye the coil pack,,could the coil pack cause a fire?and should i use my pcm from my 94 eldo,or reuse the pcm from the 95 seville?

[Ranger]

The coils COULD provide the spark, but what was the "fuel" source is the more important question.

[Cadillac Jim]

Don't switch the PCM. The 1994 and 1995 model years used different sensors and the PCMs operated differently.

[steveo412]

yup i really dont know what caused it,maybe one of the spark plug wires,the coil pack is fryed,im mean its really burnt,when i get everything back together and if there is a sensor bad and it wont start,wont my pcm tell me which one?

[steveo412]

sorry as i said in earlyer post and u can see in the last picture i posted,u can see the steel rail,the other side near the firewall is smoke damage which makes it look black,but it is a steel rail

[steveo412]

[CarlaValentine]

yup i really dont know what caused it,maybe one of the spark plug wires,the coil pack is fryed,im mean its really burnt,when i get everything back together and if there is a sensor bad and it wont start,wont my pcm tell me which one?

I'm thinking that would depend on whether or not the PCM was damaged in the fire. If it WAS damaged, then it may not be able to relay codes...or work at all. Even if it looks ok it COULD still be damaged from the excessive heat of the fire, or from electrical shorts that may have happened in the fire. The only way to really find out is to replace everything that you CAN tell is shot, and see if it will start and/or give you any codes to look at.

I agree with Jim about the PCM swap. Don't do it. It wouldn't work. Even though there weren't many differences between the two model years, there were enough to make them not interchangeable.

[steveo412]

thank u carla,the pcm looks fine,but who knows,like u said it may be damaged from the elec short,the fire didnt make it in the car,the wires looked fine coming into the car,i did read in my sevice book that the pcm are interchangeable and do work on different cars,,what it does is reset the pcm to the new config,i dont whana take that chance tho,,u can get a pcm for that car under 50$,i will do what u said and replace everything i can and see if she will start

[Cadillac Jim]

I would try to get it going without changing the PCM, like Carla says. A lot of things are programmed into the PCM, like the VIN, that you may have to deal with before it runs, and some of them may take you to the dealer and a tech with a Tech II to fix. The modules used in the Cadillac are pretty tough and I would bet on one before I pitched it on principle, particularity on that is so easy to get to.

[steveo412]

there really not that bad to get to jim,6 screws for the glove box,,unbolt the canister which is one bolt,then u have the room to unbolt the pcm,and it slides out under the dash,i will be finishing up today,i had to put my battery on a charger from the eldo,at the end it was geting hard to start!im hoping it starts right up,and if not,im hoping my pcm tells me which sensor is bad,,should i replace the spark plus?thanks steve

[steveo412]

i had to put a couple sensors under the car today,,and i noticed 2 engine mount bolts are missing,what a great mech he had working on that car

[CarlaValentine]

Good thing you noticed before you started the car. I had ONE bad mount and I swear I thought the engine was going to do a flip under the hood. It was so bad.