Engine Runaway

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I have just become a new member sort of by default. I will tell you my story. I had an apointment with the shop because I was experiencing blue smoke regularly when I had not had any before. I started through an intersection when all of a sudden my engine went full throttle. It all happened so fast that I apparently shifted it into neutral and turned off the key. The engine did not quit!! I coasted over to the side of the road and stopped the truck. The engine is still running full out(I did not notice the rpm)with so much blue smoke you could barely see. I could not get it back in any gear to try to dump the clutch (manual Trany). I thought about getting out and running but it quit after about 2 minutes. I thought that the throttle had stuck, but that was not the case. I had oil comming out of my tailpipe. I took it home and started pulling parts off. The turbo impellor was very loose and oily. I did not want to take any chances so I pulled the engine out. #1 and #5 cylinders were scored. The up side for cummins owners is after 250mi the rest of the cylinders looked like new and so did the crank and bearings. I had the block bored . 020 over and I put standard bearings in. I used all cummins parts. With the new turbo, gaskets and all it cost me about $4700. 00, with me doing the labor. That also includes new injector tips at $80. 00ea. The prices for recon engines were all about $8000. 00 so I decided to do it myself. It has been an educational experence for me being my first diesel rebuild. I have done quit a few gas engines and really this wasent that much different if you follow the book closely. I also timed it myself and it is important to time it according to the proceedure in the book, which is with a dial indicator through the #1 port on the injector pump. She runs good and is ready for a full life this time. Kind of a funny side note. I had just changed my clutch 2wk before this having to do it from the bottom side.

 

[Archive]

Ouch! Did you ever find out what caused it to wide-throttle? What year is it anyway?

-Mike

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99 QC2500 4x4, 5spd, LWB,
LSD, 3. 54, Amethyst, Agate, SLT, Fogs, Camper, Trailer, Slider, Midland CB, 2wd-low,
Smittybilt bars, Y2k alloys, Straight pipe 3", 6-disc Clarion changer, No silencer ring, Sill guards, Tailgate marker lights, and a big chrome foot gas pedal!

Mike Ramos Disciple of BOMB
"RATTLE & HUM"

 

[Archive]

I would guess this was a case of a turbo bearing failure allowing engine oil into the intake system. The Cummins apparently runs just fine on engine oil, unfortunately the governor has no effect in this situation. I have to wonder how high the rpms went before the engine seized... .....
I am glad it all turned out OK.

 

[Archive]

Your right adiabatic. She was runnin on engine oil. I still havent been able to detirmine why the engine quit. It could have sucked the whole pan dry which it did not. I ment to have my truck type and a warning to people to make sure their impellers are not loosein my signature message, but I have to get used to this system. It's a 95 12 valve unit. I talked to a guy who drives a semi with a cummins the other day. It happens enough for the truck drivers to know about it. He has taken his pillow and put it over the air intake to kill the engine. I now carry a small throw pillow for the same reason. I would quick take the cover off the air filter and cover it with the pillow. I should try it to see if it works for sure.

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1995 12valve standard cab with 250mi on engine. Had engine run away through the turbo bearing. Make sure your inpellor is not loose. Rebuilt engine myself. away

 

[Archive]

Do not allow the turbo to suck in the pillow, It has a lot of suction. On my "big rig", 350 hp cummins, I'd put the pillow on the air cleaner intake , not the turbo intake. Detroits have a air shut off lever.

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99QC,white,5sp,3. 55lsd, isspro EGT & boost, stock, 24,500 miles 11-25-99- -EX phord owner
15-16. 5 MPG hwy ,14-15 city , 10-12 with 4,000lb TT

 

[Archive]

if the oil supply to the turbo bearing was cut off,say by a valve in the line i would think the engine would quit before any damage to the turbo. what do you all think? Arnie

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arnold moos 1996 2500 club cab 4x2 all white slt 3. 54 rear end pyro,auto. trans. temp. and boost gauges on A pillar
84,500 miles 8/22/99

 

[Archive]

I heard of that happening to an old Cat 6 cyl engine, and some of the mechanics I know, have a piece of plywood ready when they start one up after injector pump work, just incase. Might be a neat idea if someone could come up with a cheap "slammer", to shut off the air incase of runnaway. (the owner's manual cautions against letting the engine "sniff" gsoline fumes off your garage floor) I saw a 2250 HP, 12 cyl, cycle GE locomotive do the same thing once, and it ran to destruction is just a minute or so, and threw parts & black oil out the stack with flames. It sounded like a model airplane engine for a short while, than sounded like a lawnmower hitting a piece of pipe, then it was over, fuel cutoff didn't work, and nothing else could be done.

 

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Hey gang,
I haven't researched sizes and pieces required yet, but there are parts for wood shop dust collectors that might do the trick.
A connector with a sliding "door" in it could be attached inline before the turbo, and when needed, could be closed to shut off air flow. Any thoughts-woodworkers?

Chuck

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1999 3500 Cummins 5spd QC-SLT(RED), Fiberglass Bedcover, Autometer Boost Gauge,Lund Screen Front-RATTLE,RATTLE;STINK,STINK
+++++++++++++++++++++++++
1998 Durango 5. 2L Auto SLT 4X4,Loaded
Rockin' Down the Highway

 

[Archive]

How about one of them RV black water or gray water dump valves?

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99 2500, QC, SLT, 4x4 ISB, 5sp, 3. 55lsd, Infiniti am/fm/cd, HDTcase, Tow mirrors, Tow Pack, Camper pack, NW Running Boards and Mud flaps, Front Mount Receiver, Tekonsha Brake Control and Husky Liners.

 

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Will a Halon fire extinguisher be effective on a diesel runaway?

 

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I worked on a nitro funny car crew once, we had this situation when a fuel return line check valve hung open and we could not shut off the engine. A quick squirt into the intake with a halon extinguisher did the job, with no damage done and no mess to clean up.
Andy