She ran away

[jj]

General Electric recently put out a notice about potential oil seal failure on the turbochargers on the railroad diesels. The seal fails and dumps the lube oil into the hot turbo. Instant RUNAWAY! In a 4500HP engine. And the lube oil sump holds 400 gallons or so. The show lasts a while. Oh, and the air inlets are pretty much inaccessible, and would probably take an oil drum lid to cover. I sort of don't want to see one, but i probably couldn't turn away if it happened in front of me.

 

[papercu]

in a pickle to get your hands over the intake.

I don't think you want to use your hands, while it won't suck you in, it is also not enough to do any good. Wayne

 

[Lifer]

My daughter's VW Rabbit diesel was fond of running away like that every now and then. She finally traded it off for something else before I could have a look at it. (She lived about 600 miles away from "home" at the time.)

 

[WillWagner]

I'm curious as to why it ran away. If it were turboed, I could understand it, but it's not. It needs to have an uncontrolled fuel source capable of feeding enough fuel into the intake, to MAKE the RPM increase and sustain it. That engine has none. Even if the engine were totally full of fuel...like the crankcase full enough to be running out the valve covers....WAIT, that could be the issue! There was an issue with the fuel system that filled the engine with fuel...close to or above the level of the top of the heads. Naturally asperated Cummins heads have a hole in the head that goes directly into the intake. This was/is there to suck some of the crankcase vapors back into the engine...it's an emissions thing. The fuel source was sucked into the intake by the vacuum in the intake through the vent holes.
Wrecker, how much oil is left in it?

 

[poppop]

I rebuilt a John Deere diesel last winter that had been sitting for awhile. On first startup it ran away. Very scary thing. I cut the fuel line and it still took a couple minutes to shut down. The rack in the pump was stuck wide open. When an engine is shut down the governor pulls the rack wide open and if its sits for a while can stick. When stuck the manual fuel shut off does not work. I was standing there ready to kill it if something like this happened but it did no good. The engine seems OK but I am going to drop the pan this winter and check the bearings. I used assembly grease on everything, so maybe that saved it.

 

[73m819]

wreckerman, did you do a pre startup motor oil level check????

 

[FreightTrain]

Here is a vid for ya of a runaway on a 4000HP engine from a turbo failure.This is what my deuce looked like when the exhaust seal failed.

[media]http://www.youtube.com/watch?v=zGoQ8XaIeaA&feature=related[/media]

 

[5_TON_TOMATOE]

Questions?

Sorry to hear about that little excitement. Hopefully nothings hurt from that that. Wreckerman, What year is your truck, and what the model? Looking at a XM816 and wondering what engine might be in it, and if turboed or not. Think its a 69 or 70- Thanks

 

[73m819]

816 has a non turbo cummins 250

 

[cranetruck]

............ I was standing there ready to kill it if something like this happened but it did no good.......

Was cutting the fuel supply your only plan or did you try to cover the air intake also? Just wondering, wouldn't a "runaway" by definition get fuel from a different source other than the fuel line?

 

[Ozarker]

Glad you're okay...eagerly awaiting the after action report once your investigation is done.

 

[AKJEEP]

It is always a good idea to keep the mix of antifreeze and water at a 50/50 mix regardless what part of the country you live in. The Antifreeze will also keep the truck from boiling over at 212 degrees.
quote]

well....almost any part of the country....

hehe

a 50/50 mix will put you good to -34, so unless you're my neighbor, you should be fine. we mix 2:1 here (2 parts antifreeze to 1 part water)
that'll take you to -65 good enough



I have an old Greyhound bus that we converted over to a motorcoach. Got an 8V71 in it....lotta throttle cable between your foot and the engine 35 feet back.
Was cruisin' along down the highway a few years back 65-70.....let my foot off the throttle, and it stayed down. Kicked it a few times tryin' to break it loose.....just made it stick a lil further down.
When I bought it, the guy pointed out the 'Emergency Stop' button and said "dont use this unless you absolutly have to"...so I tried everything else first.
if I shut down the "ignition", it just dropped the RPMs down to about 1500-1800...so I did that and rode it out 'til I found a place to pull over. Then I ran around back and yanked the throttle likange back shut and it stopped.

my understanding was that when you shut down the air and choke it to death, it will be hell to un-flood the engine. Have you tried to re-start yours since this?

 

[jj]

Thanks for the video. jj

 

[powerhouseduece]

That is the exzact reason that I loosen the clamp on my mushroom cap just enough that I can yank it off in a pinch.

 

[Capt.Marion]

Glad you were able to stop her before you became a genuine certified "former" pyrotechnician. I hope you are able to get her all sorted out. No fun having a non-running truck sitting there staring you in the face.

 

[73m819]

on a DD motor, when you use the emergency shut down, it shuts the air to the supercharger, this causes a major vacuum which tries to suck to super charger drive seals, you can always tell a DD that has been shut down repeatedly by the emg. stop ( some people are real lazy and or dumb), by the amount of oil it uses and the blue haze it puts out
i have seen emg. shut downs spring loaded to close and the hold open tab gone, and thay wondered why the oil use was so hi

 

[poppop]

Bjorn, i was way dumber than that. I thought the mechanical shutdown would kill the fuel. WRONG!!! The mechanical shut down pulls the rack all the way back for fuel shut off. If the rack is stuck it does not work. I did not know that. When it ran away everyone got real excited. Those with no monitary stake in the engine ran. In hind-site I should have removed the fuel filters. That would have shut it down much quicker. I was building this engine for an irrigation pump power unit. It now has an electric fuel shut-off valve mounted at the injection pump, wired into the Murphy Switches and with a switch to kill power manually. Cut the fuel off at the pump and it should die very quickly.

 

[FreightTrain]

ok,Got back from a little autopsy work.Not good.Oil sprayed over an area 50 foot wide by about 500 foot long.I would say,3 gallons maybe a tad more sprayed over everything.Both sides of motor,hood,top of motor,basically everything from the cab back wall to teh bumper soaked in liquid.Checked dip stick,it is 6" above the HI marking.VERY thin.Diesel smell.Didn't see any gold chunks on the dip stick so the bearings might be ok but it had so much fuel in the oil it sprayed out of the rocker boxes somewhere.Might go back up next week and pull the rocker boxes off and replace all the injector O rings.Hopefully the head ain't cracked allowing fuel to get into the oil.

 

[doghead]

Was the coolant level correct?

 

[m16ty]

A 250 Cummins doesn't have a rack to stick. The fuel pump supplies constant pressure and the injectors fire off the rocker arms. There is a governor in the pump so I guess it could stick.

Does the truck in question have a either start? I'm wondering if it could malfunction and cause a run away?