Then came the engine fire....

General discussion about our beloved Tercel 4WD cars
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Then came the engine fire....

Post by Petros » Thu Oct 04, 2007 10:04 pm

I am driving my daughters to class one morning as normal, and then the head and dash lights appear to go dim when I put in the clutch. Odd, there is nothing electrical in the clutch system.

Then the car died between shifts, but restarted instantly when I let out the clutch. Then my tach went to zero, and my instrument panel went out for good. That is when my daughter said she smelled something "funny", I smelled it too, but it was not a real strong smell. Maybe it was from outside the car since my defroster was on.

Humm, it was not over heating, and besides the problem with the elecrical system, it was running normal. But them my aftermarket oil pressure gauge went to zero. I had just changed the oil last week so I know it was full. That is when I decided to pull over and take a look. I did not pull over sooner since I did not want to make my daughters late for school, since it was still running okay. but now either something was wrong with the mechanical oil pressure gauge or I am about to ruin my bearings.

I see smoke coming from under the hood as I got out of the car. I lift it open and am greeted by flames licking out from the starter/distributor side of the engine. It has the wire bundles fully involved and melting off the insulation. It had melted through the nylon oil pressure line (which was feeding engine oil into the fire ).

I snuff the fire out with some coveralls I had in the back and then assesed the damage. It appears none of the wires are broken and if I can separate out the strands and wrap them with electrical tap it will still run. I folded back the oil line and wrapped tape around that to hold in the oil, I get all the wires separated and wrapped. But the electrical is completely dead, not even dash lights. The big 60 amp main fuse is blown so I jam a foil gum wrapper into the space between the contacts, and then double check the jury rigged wire bundles. Add two quarts of oil to the engine, then it starts!

I tell my daughter "see what adventure it is driving a 24 year old car with over a quarter of a million miles on it?" Think how boring life would be with a normal reliable car to drive everyday.

Some friends stop in the minimarket we were stopped at to get breakfast and offer to take one of my daughters to school since they are head there, I manage to get the other one to class only about 10 min late.

I get the car apart that night to find the cause and fix the damage. I thought that perhaps the oil pressure line had chaffed and leaked oil on to something electrical which started the fire. But that did seem right since after removing the starter and looking it over closely, it appeared to be fine. I have a spare and put it back in just in case.

I pull the distributor and it too looks fine except the big green plug on the end of the pig tail is melted into a solid mass, and all of insulation is burned off the outside wires (and it was still running, I drove it like that for about 30 miles to get to work and then back home). I replaced the distributor with one of my spares. All the other components looked fine. I replaced the damage wires by splicing in replacement wires, but I could not isolate a cause.

It is running back to normal but with a more rounded "organic" looking distributor cap, i.e. slightly melted on the outside (hey, it was fairly new and I did not have a spare, and it looked fine on the inside).

Now I think that perhaps the wire bundle that plugs to the distributor may have been frayed and caused the short, and melted and ignited the insulation on the wires. After that melted my oil pressure gage line it started feeding motor oil to the conflagration.

Any other ideas on what might be the cause?

Anyway I got off fairly easy, only two quarts of oil and $3.99 for a replacement fuse (somewhere I have a spare for that too, but I could not find it). It could have done much more damage, including engine bearings and a lot more if it melted the fuel filter, that is only about 6 inches away from the fire. That would have been too much excitement if that had happened.


Peter
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

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SinusoidalTendencies
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Joined: Thu Sep 06, 2018 12:06 pm
My tercel:: 87 4wd wagon

Re: Then came the engine fire....

Post by SinusoidalTendencies » Tue May 21, 2019 4:19 am

wow,,, that is one crazy story.

did you ever figure out what happened?

hows the car now?
I don't always learn my lesson.
But when i do, it's the hard way.

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Petros
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Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Then came the engine fire....

Post by Petros » Wed May 22, 2019 5:17 pm

still driving it, with more permanently repair wire bundle.

I suspect the ancient wiring had the insulation get brittle and crack off the wires within the bundle cover and shorted within the bundle. there would be no way to see it without cutting open the black sleeve that covers the wire bundle. the wires run along side the block where they get hot, and the insulation has become brittle and cracked off on other wires I can see, so I suspect it was just old crumbling and cracking wire insulation allow it to short out.

I now route the bundle further away from the side of the block. strange things happen on old cars you keep running long past their "use by" date. now it has over 400,000 miles and it is 35 years old (well mostly, most of the moving parts have been replaced several times over).
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

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splatterdog
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Location: Minnesota, USA

Re: Then came the engine fire....

Post by splatterdog » Wed May 22, 2019 5:36 pm

T4's are fairly fire resistant, as tested by my wife. Twice

Glad your car survived!

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garyfish
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My tercel:: 1985 Tercel SR5, stock; 1987 T4WD DLX wagon, manual tranny
Location: North Coastal California

Re: Then came the engine fire....

Post by garyfish » Sat May 25, 2019 8:14 pm

About decade ago, I had a problem with melted wires in the bundle below the distributor. No fire though, just acrid smoke.

I dealt with it similar to the way Petros described it. I separated the melted wires, none of which were broken, and either spliced in new wire or wrapped them with electrical tape. After everything was all back together, and after replacing the main fuse, it ran nicely.

I then used a couple of long zip-ties to pull the bundle away from the block. Never had another problem with that wagon, which ended up getting stolen a couple years later. :-(

I've owned three T4WD wagons since then, and on every one I've taken the preventative step of pulling that wire bundle beneath the distributor away from the block. It only takes a few minutes to do it, and gives me peace of mind that I'll likely never have a problem with melted wires there again.
1985 Tercel SR5 4WD wagon, 300K
1987 Tercel DLX 4WD wagon, 6-speed manual, 251K -- got this one running Jan. 2015 (had been sitting for 2 years)

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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Then came the engine fire....

Post by Petros » Sat May 25, 2019 11:12 pm

Greyfish,

that is exactly where my wire bundle had melted, than ignited the plastic wrap, than melted the nylon aftermarket oil pressure line, which started feeding hot motor oil on to the glowing red wires there.

I think the wire insulation gets brittle being next to the block right there.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

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marlinh
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My tercel:: 'Everett' Blue mint 4WD wagon and 'Rocky' 86 4WD Wagon
Location: Kootenays

Re: Then came the engine fire....

Post by marlinh » Wed May 29, 2019 7:12 pm

I've seen them chafe in that spot if the wiring bundle isn't supported properly. Good area to inspect as it is usually covered in oil and dirt.

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