Run away diesel!?

Happens! Particularly when rebuilding one. It also why you ALWAYS have something handy to slap over the intake. A runaway will go to explosion in fractions of a second.
 
When I was in the Marine Corps and deployed to a Nationalist Chinese Air Force Base on Taiwan, we were operating under field conditions and had two 50 KW diesel generators powering the mess tent.

One evening during supper, when the mess tent was full, one of the generators ran away. I don't know what caused it, governor failure or whatever, but rpm of the engine just kept going higher and higher until it was screaming. Everyone watched, but no one was about to go near it. Finally something broke internally and it wound down and stopped.

Made for an interesting meal.
 
Story I heard was of a propane pipeline repair crew. Drove a TLB too close to a gas leak. The engine pulled in the gas fumes and went into
runaway.
 
Local boy just out of a diesel school in Nashville, Tenn was smart but had little experience went to work for a repair shop and was called to do a service at a sawnill, The Detroit 6-71 was under a sheetmetal shed had no muffler, When the engine started the guy thought it was overspeeding and ran back to the service truck. He had not heard a Detroit start normally under a tin roof. The mill hands laughed.
 
Hi, as some one mentioned, I had something
similar. I was installing a sewer line at a new
house and I was just at p/l when my backhoe
pulled a gas line out of the dresser sleeve. The
natural gas got sucked into the breather and
engine really rev'd up. I knew what happened but it
sure gives you a few anxious moments. I raised the
boom and drove ahead some feet. It came back to
normal. I had that happen 2 times in 30 years. Ed
Will Oliver BC
 
I was trapped in a housing on a generator. When one took off. No way to get to anything had to wait in the corner. Until it let go. Not a good day for me. Think my shorts turned brown.
 
In diesel class at collage we had the ag
tech(Deere) class in same building as the
diesel class. Someone messed up the rack on
an old 2 stroke Detroit, soon as they
started it she ran away. They put a book
on intake and that did nothing. It finally
self destructed. I took cover behind a 7720
combine.
 
(quoted from post at 11:19:59 02/22/18) In diesel class at collage we had the ag
tech(Deere) class in same building as the
diesel class. Someone messed up the rack on
an old 2 stroke Detroit, soon as they
started it she ran away. They put a book
on intake and that did nothing. It finally
self destructed. I took cover behind a 7720
combine.
hould have had a teacher that really knew Detroits & he would have know immediately the correct shutdown for a run-away.
 
Older fella I know , used to drive high way tractor , hauling gas to service stations in the early 60's.
They put him in a new truck, a Diesel , only the second Diesel truck in the fleet,all the others were still
gas jobs. The tankers at that time all pumped with a PTO pump driven off the tranny, so the truck was left
running while unloading , to power the pump. He had been on this new truck about two weeks , and was
putting a load off one evening at a station . Very calm summer night, no breeze at all. Told me he went up
on top of the tanker and opened the air vents , got every thing set up, back into the truck to engage the
pump, all is good. Then all hell starts to break loose, truck engine revs like wild, tries to shut it down
, but there is no killing it, and it is running away. He takes off running, and she blows. The blast when
the tanker blew flattened him , next thing he knew, was waking up in the hospital. The cops , his company
,and their insurance company wanted to know if he was smoking while unloading the gas, they were all sure
he was, but he said that he wasn't. Week later the other truck in the fleet blew up same way. They figured
gas fumes from the tanker, were being drawn into the air intake of the Diesel truck, and caused it to run
away. No more pto pumps on those big trailers, and I have no idea what they do now, perhaps gravity ?
 
Up here in these parts, all diesel engines on production sites (refineries, etc) have to have the shut-off valves installed on
the engines. I think there are a variety of ways they work, mechanical, electrical, etc. They still make them here locally
and you find them world wide. Our club had a field trip tour through this plant a number of years ago .....
Untitled URL Link
 
Had that happen to a 7700 combine my Dad bought. Had been sitting for about 7 years. Jump started it, and it revved up. the switch wouldn't turn it off. So I went to the shutoff valve on the tank. Turns out the rack was stuck in the injector pump. Now every time we start that thing for the first time in the fall it is a two man job. One in the cab, one at the tank.
 
Not sure what happened to my first post.

https://www.youtube.com/watch?v=NgB1dDunbOg

https://www.youtube.com/watch?v=vbiNndfNNKI
 
I saw it happen once on an 84 Chevy van 6.2 diesel. It was at a shop I was working at, the fuel filter was being changed and the thing wouldn't start afterwards because of air in the line or lack of prime. So the guy working on it was spraying large amounts of JB 80 into the intake to try and get it started. It finally started and rpm shot to the moon for about 20-30 seconds. No immediate harm became of it, and I remember wondering how it ever held together. Everybody scattered as I remember !
 
We had an old Michigan loader at work that had a 3-71 Detroit used to have to use the emergency couple times a day as the Detroit would just all of a sudden just take off.
 
Took the diesel technology course at the
local community college a few years
back.Part of the course required complete
disassembly and reassembly of different
diesel engines.One guy had just put back
together a 6-71 detroit and had it on a test
stand to start up.Well the engine started up
ok and it kept revving higher and higher and
higher,pretty soon that ol' jimmy was
screaming.By now the engine is eating itself
alive and all the instructer could do is
close the door in the engine room and get
all the student's the hell out of the
shop.Now there's smoke pouring out of the
engine room and filling the shop with smoke
and smoke is pouring out the open windows of
the shop and that jimmy is just screaming
and then she lets loose with a pretty decent
bang as smoke continues to pour out the
windows.Students and faculty were coming out
of the nearby classrooms to see what was
up.It was a sight to behold man I mean smoke is
just billowing out of the windows.Lesson
here was make sure governor is right and
have a 2x6 ready to block air flow to the
engine.
Paul
 
Detroit's are good at it. 1st thing in Detroit class, keep a clipboard handy, if it starts to run away stick
the clipboard over the intake. Engine shuts off because it can't pull in any air. Saw it happen once in
class. Kid didn't have the rack set right.
 
The only experience I have had with anything close to a runaway was when the ECM went bad on my 98 1/2 Dodge Cummins. I started it up, touched the foot feed and away it went wide open. I could kill it with the switch though. I don't know if the governor would have kept it from over revving because I killed it right away. I assume the governor is still mechanical on that engine but I'm not sure on that.
 
Isn't that what caused the Deepwater Horizon disaster... diesel engines on the oil platform got a whiff of natural gas and grenaded, setting off the rig explosion, IIRC.
 
When I was in the Army, there was a young mechanic that started a 8V-71 in a self propelled howitzer, only he forgot to hook up the rack, and shutoff to 1 bank. It got screaming pretty good before we started feeding it anything it would take. I lost my field jacket and some TM manuals. Others also lost jackets. It was scary to say the least. By the way, that was the spring of 1966 I think.
 
Had a 6.5 Chevy diesel that was notorious for this. Been
several years ago but there was some kind of small electrical
box that controlled the fuel. As soon as that box got warm it
would go straight to the rev limiter would shut it down and wait
for it to cool. Glad that truck is gone
 
Riding in an Army bus at Ft. Belvoir, headed to a demolitions class...engine blew out the bottom. Driver claimed it was a runaway, but we knew he down-shifted at high rpm, and it over revved.
 
We had a chaining contractor with two D9 flat tracks. One wouldn't start and he got on to his service technician. Whose message was to be very careful as there was a bearing in the governing system that, if worn, would cause a run away. One driver had been around one that did it and didn't recommend the experience.
 
(quoted from post at 14:48:31 02/22/18) Really should never run a Detroit that the emergency stop isn't working.
ou are only one of two in this entire thread that seem aware of the emergency shutoff flap on the Detroits.???
 
Another cause is oil leakage inside the turbo. If an engine starts sucking on that, it will run the engine dry on oil. Cutting fuel won't stop them. Either blocking the air flow or snubbing the engine if you're lucky enough to get the tranny in gear.
 
A run away diesel engine also caused the Texas City oil refinery explosion in 2005 which killed 15.
 
Hi, as some one mentioned, I had something
similar. I was installing a sewer line at a new
house and I was just at p/l when my backhoe
pulled a gas line out of the dresser sleeve. The
natural gas got sucked into the breather and
engine really rev'd up. I knew what happened but it
sure gives you a few anxious moments. I raised the
boom and drove ahead some feet. It came back to
normal. I had that happen 2 times in 30 years. Ed
Will Oliver BC
 
I used to run a octane/cetane lab in a refinery. The cetane engine
was used to determine the cetane rating of a sample of diesel fuel.
These engines revs are held back by a electric motor. If a electric
power outage occurs, then the diesel engine becomes a runaway and you have to cut off fuel to starve engine. Had this happen many times.
Ran many a mad dashes to the lab when I saw the lights flicker.
a258095.jpg
 
Hi, as some one mentioned, I had something
similar. I was installing a sewer line at a new
house and I was just at p/l when my backhoe
pulled a gas line out of the dresser sleeve. The
natural gas got sucked into the breather and
engine really rev'd up. I knew what happened but it
sure gives you a few anxious moments. I raised the
boom and drove ahead some feet. It came back to
normal. I had that happen 2 times in 30 years. Ed
Will Oliver BC
 
(quoted from post at 16:24:12 02/22/18)
(quoted from post at 14:48:31 02/22/18) Really should never run a Detroit that the emergency stop isn't working.
ou are only one of two in this entire thread that seem aware of the emergency shutoff flap on the Detroits.???

Yes...the emergency flap or the cable are always stuck or un-hooked on the two stroke Detroits.

I over-hauled a 4-53 in a Oliver 1950 last summer. Of course the safety butterfly ahead of the super-charger was stuck...cable un-hooked to the governor...

I learned my Detroit lesson early on with a 8V71. Truck shop I worked in needed a 'new' engine for a customer's truck a cab-over Marmon. Anyhow..the customer bought a used..but supposedly 'good' 8V71 from a salvage yard. The lead mechanic and I got the power-pack out of the Marmon and had the replacement V8 hanging on the A-frame hoist and the lead man had the brilliant idea to start the thing before we installed it(good idea as it turned out).

I got a can of fuel rigged-up..lead man rolled our battery cart up to the engine. we set the engine down on wood blocks but still hanging on the hoist too. Jumpered the big Detroit and it took off right away and promptly began running away!!

We had the valve covers off so we could manually control the rack/racks...but no good!! The engine was just screaming and blowing solid black smoke and oil out the right bank...then the left bank too! I watched the lead mechanic disappear in the smoke as he was fumbling with the safety butterfly..I grabbed the fuel can and ran!! Engine would not die..just screamed louder with no fuel!!??...and blowing solid black smoke and oil out the exhausts....Lead man runs out of the cloud unable to shut the engine down!!

We just let it go!! The engine torqued itself off the blocks and swung around on the hoist until it's front pulley was against the leg of the hoist...was shooting sparks out the exhausts...and off the front pulley!!...all the while spraying oil and solid black smoke out the exhausts...it finally ran out of motor oil and locked-up....

There was a white Pontiac Grand Prix in the shop about ten yards behind the engine in line of the exhausts...the car was black with burned oil after the event!....I was black too...the lead mechanic was a black man anyhow...but he was really really black after the event!

Turns out there was a broken piston crown on the right bank...the piston cooler nozzle was supplying motor oil directly into the combustion chamber through the hole in the piston...the oil was getting distributed to all the cylinders through the air-box and she just ran and ran until she stopped....

We got a major azz-chewing for turning the bosses daughter's Pontiac black....No moral to the story except to always make for sure your Detroit's safety butterfly works
 
. I always left the air pre cleaner cap just snug on my 2-53. Glad I did as one day while using the rotary cutter she tried to run away. Turns out the governor internals failed . Whipped the top off the air intake and throttled the rpms with the palm of my hand on the trip back to the shop.
 

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