runaway engine?

A buddy of mine just nuked the motor in his turbo diesel Isuzu box truck, said the engine starting sucking the oil up into the combustion chambers, and ran uncontrolled until the engine siezed due to no oil. Reading the TM's...says if you pull the engine stop and engine keeps running, take cover (and of course, notify maintenance). Have I connected these 2 circumstances correctly? Anyone ever heard of this happening to a multi-fuel engine?

It does in fact happen to multi-fuels once in a while. You could try putting the truck in fifth gear high range with the parking brake set and dump the clutch to stall it out, but be careful because due to the high RPMs it might not stall out and you might be going for a ride.

The other way to do it is to pull the intake mushroom off and use a 2X4 or ping pong paddle, anything other than your hand to choke off the air going into the intake.

I think your parking brake must work better than mine! I guess I'll add ping-pong paddle to my list of necessary equipment, just in case...

I've never had to do it on an MV, but we have a Peterbilt at the farm that has acted up a few times and the parking brakes, locked up air brakes worked just fine for that. However for a Deuce I would definately rather just block off the intake.

crazyplowboy said:

The other way to do it is to pull the intake mushroom off and use a 2X4 or ping pong paddle, anything other than your hand to choke off the air going into the intake.

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Other then some people that party way to much in there shop, not too many people are going to have a ping-pong paddle just laying around...

Well since the mushroom cap is clamped on, sometimes they can be a bummer to rip off in a pinch. But if you can get the cap off the intake, you can simply just spin it around and use the top of the mushroom cap to cover the intake pipe.

Ask me how I know that!

powerhouseduece said:

Other then some people that party way to much in there shop, not too many people are going to have a ping-pong paddle just laying around...

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My 818 tried that last week as I was trying to start it, maybe 30 minutes into the ordeal, I pulled the emergency stop as it started to rev! Fuel problems?
James

I do remember the Detroit 6V92 TTA run away - you had the blower open for access after running the rack - it took at least a 5/8" plate steel with a handle welded on it to hurry (and I mean HURRY) in the fastest terms possible) to get the blower covered as soon as your 6th sense told you the engine was in the runaway incubataion stages. If you hesitated for another 5 seconds - you might as well get as far away as you could - was not worried about flying parts - it was literally the screaming of the engine that was ear piercing.

Then be prepared for a payroll deduction.

I remember a guy trying to shove a 5 gallon pale over the blower in the start of a runaway engine - sucked the end of the 5 gallon bucket right clean off.

A set of Vise-Grips on the rack is good insurance for Detroits and a Co2 extinguisher will snuff out a runaway.

Been there, done that. 22 years at work, had 2 do it. Both times, the customer drove the vehicle in. I got in them to move them around to the shop, got one of them up to the shop and I heard a litle "odd noise" and pulled the engine cover...it was a front engine shuttle bus, so the engine was under the floor to the right of the drivers seat. I gave it a bit of throttle cause the little "tic" happened at around 1000 - 1200 RPM, next thing you know, the RPM is climbing, like RIGHT now, faster than I have ever heard a "B" throttle up. The guys standing in the door took off running, I was trapped in the drivers seat with a 359 CID engine spinning fast enough to bury the needle on a 4000 RPM tach, 18 inches from my body parts...they get real quiet up at that RPM! Everyone said my eyes were as big as coke bottle bottoms. I couldn't go out the window 'cause it was only big enough for my head...ask me how I know. I REALLY didn't wanna exit over the 4000 RPM + engine for fear that a pushrod would exit through the valve cover at that exact moment, if you get my meaning . I ended up jumping over the engine to exit and by the time I got back with an extinguisher, the engine had started to die on it's own...outa fuel and lube! The turbo had failed and decided to fully let go as I was looking at it. That was about 10 years ago.

The latest, about 6 months ago, was a USC bus...guess I like busses! NOT! It was running on 100% bio and the customer was complaining of intermittant smoke. I went out to the bus that the customer just drove in, the customer was standing there and the engine was running and it started to smoke a few little puffs of white/grey smoke, just like they were complaining of, then the idle went up a bit, by itself, to around 1000 RPM. The guy that brought it in, a "maintenence" guy from USC, looked at me with an expression i'll not soon forget as I returned the same look to him, and I knew what was about to happen. I ran the 40 feet to the front, turned it off and had the key in hand when the RPM just kept on goin'! The USC guy was running around in circles at the rear of the bus, flappin his arms like he was trying to fly away! I ran into the shop and got a Co2 extinguisher and was able to snuff it out without the engine destroying itself. This was also caused by a failed turbo putting oil into the intake...an uncontrolled fuel source.

Two events I will NEVER forget!

Thats a great idea on the Co2 extinguisher. You could mount that on the outside fender next to the intake on a deuce or 5 ton. I think I going to look in to that.

Just removing the mushroom and covering the intake will not shut off a runaway engine. It will lower the RPM's quite a bit though. Remember almost all M35's do not have a fording kit installed, so there is about a 1" hole in the back of the air cleaner that must be plugged before the engine will shut off.

It sounds to me like in most cases its due to a failing turbo. Does that mean the Cummins 5 tons are safe from this happening? How would the Cummins 250 get the motor oil into the intake?

I AM JUST ASKING, I AM NOT A DIESEL MECHANIC!

Negative, The one runaway I had was a non turbo and the problem was the injection pump. Though turbos are another often cause for runaways.

hndrsonj said:

Negative, The one runaway I had was a non turbo and the problem was the injection pump. Though turbos are another often cause for runaways.

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so i guess the only solution is to pull the KILL lever and shut off the power switches?

Well during my runaway I wound up with the cable in my hand from pulling so hard. Twright also had one and the cable did not shut his off either, he also had to remove the mushroom and place a board over intake then cover the fording access point for the compressor with his hand.

Some more info, Tonys was a turbo however, it doesn't appear that the turbo was the problem. There is no indication that it is at fault. I am curious since both trucks were always run on straight diesel, if the new sulfer rules on diesel fuel that went into effect early 2008 have any effects on the IP's? I was told by a diesel mechanic that the older diesel fuel had more lubrication properties. Now I have NO clue if this is true or not but it does make one have to wonder. Maybe an additive in the fuel tank every now and then would not hurt?

If you have a non-dented and near-perfect mushroom, I don't see why that pulled off quiclky and fliped over and put on the intake pipe would not kill the motor instead of having these other things to carry around like a board or ping pong paddleor such. It takes so little time, where hunting down the other device-'s could take a minuate retreiving it from under the seat or wherever.

I did not see it happen , but saw the after effects of a run away on a museum quality, Deuce tractor. Rod right out the block. He said he fired it up an the rpm's went right through the roof. The stop cable did nothing until it destroyed itself, which only took moments. This instance must have been a bad turbo we suspected.

One day while performing pm on my truck I tried to snuff it out at an idle with the mushroom and a rag, or whatever, and it did not effect it all, just kept running.

The fording access in the back of the air cleaner assy must be blocked or it will keep running. I would think the mushroom would also work if it was in good shape. I just happened to have a board laying right there (was actually standing on it).

When my 250 Cummins tried to go high order it was because fuel had got past the pump seals and filled the crankcase with a diesel/motor oil mixture.
I had put a temp fuel tank on the back deck of the wrecker and the weight of the fuel pushed it past the pump seals.
When I cranked it up it idled fine for a while and then the RPM started to go higher and higher (with no assist from my foot).
I realized what was happening but there was no stopping it with the shut off.....I ran into the shop and grabbed a big cloth towel and got it stuffed into the air cleaner.
It ran WFO for several minutes and the damage was a FUBARED piston and liner.
The poor wrecker is still deadlined.