I posted my experience in the thread that would not allow folks to post to it. So here we go lets try this again. Please post your or others experiences with Engines going out of control for what ever reasons. Similar to some of these.
Company I worked for had a couple old scrapers,, open cab. One fella used to have a can with gas and a rag in it. If he wanted an extra boost, he would hold the rag up to the air cleaner. I remember my father talking about a guy putting fuel in an oil bath air cleaner. Ran ok, but once he gave it some throttle, she took off, and pow.
Need a video of that, was it a detroit?
No idea I was just a youngin when he told the story. Only oil bath air cleaner I have ever come across was on an old tractor. Wonder if the shut down flap on the blower on a detroit would kill her in that instance?
Had a 3116 run away on me in tech school stuck injector. These engines had been tore down and reassembled a lot but we were the first class to run them after reassembly and they were already pretty old at that point anyway. I slammed my clipboard over the turbo air inlet to shut her down.
Here at the WWCC diesel program one of the instructors slammed a clip board over the turbo on a 3406B on front of the class to show how to shut one down. Sucked the Masonite board right through exploding the turbo.
I had a boss that told me his clipboard story as well. He had not pre-planned it, just happened to have the clipboard in his hand and it worked that time. I have heard enough failed clipboard stories since then I will not be using that as my default method. Nor a paper service manual.
Tried to shut both blower flaps on a Detroit 12v 71 Twin Turbo and it would not slow down . Only the fuel supply being shut down stopped it. Were very fortunate as engine was okay after the episode. Have heard of some bad outcomes. The fuel Shut Off Solenoid had failed ... Simon C
Had a ISX15 2350 Cummins in for an injector miss. Truck would barely run. Started cutting out cylinders, #3 had no change. Turned #3 back on and the engine took off. Ecm showed 2500rpm before the key was turned off. Had to turn off taps on fuel tanks to get it to shut off. Tried baring over engine after, locked solid. Had to do crank/rods and all injectors.
And if it is a blower or turbo seal, pinching the fuel line will not help.
The one that would constantly take off on me, at cold start up was a D353 in a pony start D9, in times like that it is sure nice to have that compression release lever. The Detroit V12 story is interesting, I would have thought for sure the E stop flaps would have at least slowed it down a bunch. They sure do a good job preventing them from starting. I suppose the best thing to have on hand is a nice Co2 extinguisher, if you ever have one take off. If equipped with Jakes that should also help the situation. I'm not sure what engine was on it, but I had a friend that lost a part of his leg from an over speed engine on a pump I think it was, not sure what flew off either. Yeah stopping fuel will not always work, since the engine could be running on its lube oil.
I was probably 9 seen a 6 71 that hadn't ran in years it fired up and went to the moon the mechanic that fired it up without panicking or wasting any time grabbed pliers and pinched the fuel line shut
Yeah for any diesel engine a nice quick ball valve in the fuel line should be mandatory. Like mentioned won't always shut them down, but handy if the problem is fuel injection related.
I've seen two. One was a worn out pos Double OO detroit in a 79 W900 on site end dump extreme piece of crap. The whole fuel system, rack, rods, governor was worn out. It would eat two gallons of coolant a day, you could smell the oil/coolant vapor in the cab, it was a fog out the breather drains. One cold morning I'm on site and the construction crew fired it up as usual with a can of insta start. She started rolling real hard and rpm rising each time, after about the 7th roll she went haywire. Operator ran over {YOU GOING TO SHUT THAT DOWN?--- Not me I'm not going to lift a finger to save that pile. It finally hucked one through the side-made a real cool sound. One of the best things I've witnessed. The other a 12v71 fresh rebuild on the test stand-injector hung. it was saved.
Since I have been rebuilding and fixing Detroit's for over 35 years, I've had 4 different runaways that are memorable to say the least. 1. The first is always the one that sticks with you. When I worked for a Terex dealer, a buddy of mine had just finished a fresh 8v71T build. I wasn't involved with the build at the time ( I was still a apprentice back then) but I did help him set the engine up for start up and a run in. He primed the fuel system and after about 5 revs she took off. First thing he did was trip the blower flap.............barely made a difference. That really bad thing was he had already put the valve covers on so there was no access to the fuel rack (He was always paranoid about oil splashing). He then started shoving shop rags into the intake ( I was like "*** is that going to do?"). By this time everyone in the shop had cleared out, sprinting for the doors.........left us to there to shut it down or die. When I realized the engine builder didn't know what to do next, I reached over and grabbed a hammer off the table and smacked the fuel line off the top of the filter housing. About 15 seconds later she laid down and died. He was pissed I broke that fitting off in the filter housing LOL....I got a good laugh out of it. Seems when he put the governor top on the drive pin didn't go into the yield link fork......had the governor locked. 2. The 2nd one was a 6V53 in GMC truck. I was working for the Fiat Allis dealer then and was called out to one of our best customers that said a truck of theirs kept climbing in rpms. I get there, the truck is in their shop with the hood off waiting on me. I remove the valve covers and don't see anything obvious, so I climb on the truck and sit my ass down on top of the radiator with my legs spread and each foot on the inner fender wells. I ask on of the mechanics to get in the cab and start her up. The engine immediately shot to the moon and since the valve covers were off and the fan going what seemed like a million rpms........It splashed so much engine oil in my face I couldn't see anything. I had a bundle of shop rags next to me so while this engine is going off, I wipe my eyes good enough to see that everyone had cleared the shop and was standing outside an open bay door..........left my ass there to die (This seems to be a common theme). I tried to find a blower trip, not one there on this engine. I start yelling at the top of my lungs for someone to bring me a hammer or vise grips.......one guy gets brave enough to toss me both after walking gently towards me. I took the vise grips and pinched the fuel line off and a few seconds later she came down and died. I looked like I had fallen into a pit full of used engine oil. From start up to finish this whole thing seemed like a lifetime when it was only a minute or so. All I could think about during this was at what point was the fan going to sling off a blade and cut my legs off. The problem ended up being a loose clamp on the fuel rack dirt tube that had rolled against the rod and froze the movement of the fuel rack. 3. This one was my fault. A fresh rebuild I did on another 6V53. As I was installed the engine back in the machine, I didn't notice that my lift chain hook was against the dirt tube (like above). It bent it just enough to make contact with the rack rod and I didn't notice it. After the first 2 runaway experiences I learned to have 3 methods of shutdown ready (LOL).......my best being a pair of vise grips on the fuel rack tube so I can manually override the governor. I rolled the engine over and off it went..........although I was able to get her shut down in about 10 seconds. The funny thing was the company owners office was on the other side of their shop wall and after I got it shut down, he comes walking in through the shop door and says "Is there a problem?" He said he had never seen his office people move so fast out the front door. 4. Someone had been trying to get a little 3-53N running on a trackmobile. They never could get it to run so I got called out. They had been screwing with the fuel lines and had that all screwed up, so I went about fixing those and installed a new restriction fitting to replace the non-correct standard fitting they had put in it. What I didn't know until afterward was they had been screwing with the governor and didn't tell me. I started rolling the engine and once it got fuel pressure she went to the moon. I just so happened to have my needle nose vise grips in my pocket so I clipped the fuel line. I swear this engine still took almost 30 seconds before the rpm dropped and she died. This engine had an open governor and come to find out, they had attached a spring on the wrong side of the fuel rack assist...........locking the fuel rack into full fuel. If their mechanic had been able to get the engine fuel this engine would have died on site. The good thing is all the examples above were saved. I haven't lost a runaway as of yet. One thing I know for sure.........it takes a brave soul to stay in there once it starts................or a dumbass. I'm not sure where I fall in there yet.
I have told this story before. I pulled the a plungers out of a 3406 pump. I didnt to because i know what could happen And i didnt understand every thing about putting the pin in the pump rack. I had a helper to start the truck i had removed the hose on the turbo and told him what to do if it took off and i couldnt do it for some reason. He hit the button and it started and took off out of the corner of my eye i saw him jump from the cab and run . I got a board on the turbo and killed it. He came over like nothing had happen. I later did a inframe on it and removed all the plungers. We went to start it and it wasnt getting any fuel the driver was there so as soon as it started he was going to take it on a trip believe it or not. He got in it and it started. I ask what he did he said he push down on the gas pedal we never had to do that before. We ran it half a hour and he drove off. The next time i saw him he told me that truck never ran like that before. I dont think the plungers and rack were in the right place. What ever it was it didnt hurt any thing they used it along time.
A funny one I towed. I got a call for a broke down pete cab over had a silver. When I got there the driver looked like he had seen a ghost except he was covered in soot {it had twin funnel stacks} You could see his eyes and teeth. It started to gain rpm between shifts so he pulled over called his boss {boss told him to turn the buffer screw {out} he did so} you can guess the rest.
I didn't bother to save that OO. The crew was so happy it died and they didn't have to drive it anymore, I had free beer at the tav for two nights.
How about some of the real bad ones when they are running on crankcase oil? So I guess Detroit just added those E stop blower flaps to make people feel good, strange they don't even slow the engine down?
But the flaps do work sometimes.........in normal conditions. Because of their design, Detroits end up with A LOT of diesel in the engine oil. Thats why its very important to keep the oil changed regularly and the air box drains clear. If you have to hit that flap, your engine is already running away. The engine will immediately seek an air source while its turning.....and can pull in the dieseled oil from a filled air box, wrist pin retainer, blower seals, ect....and run away on that alone completely over-riding the fuel system and governor. In those cases the flap isn't worth a dam. These type of runaways are impossible to stop. I have been very fortunate to not have experience in this. I cant even count how many times I've gone out on a Detroit in the past and found bolts, sticks, or whatever stuffed in the ends of the air box drain lines .........because they "leaked" oil on the ground. By doing so they have set themselves up for a disaster at some point. I have also seen many that use the flap to kill the engine when their fuel stop cable froze up. Doing that will suck the blower seals out, which in turn feeds engine oil into the air box system.
I have a well worn 6-71 that runs ok with the blower flap closed, just smokes a little more.
Probably needs to have it adjusted so it seals better. Also sometimes those flaps get rusted/corroded from lack of movement and when needed to work they don't.
I wonder if spraying a fire extinguisher in the air filter inlet would stop a run away?
They say a CO2 extinguisher will stop it, but as long as some engines keep spinning after you shut them down, I have my doubts, because if the extinguisher ran empty while the engine was still rotating, it would be right back off to the races.
And I would not like to think what would happen if someone did not understand that the idea is to use a CO2 and not Dry Chem extinguisher. Guess it would be better than the damage done if it grenaded!
The old halon extinguishers would probably work well but here they are not legal anymore and I haven’t seen one in years
I have not had a diesel run away, but I have found a broken mag wire the scary way on an aircraft engine. you do a fuel cut to shut down the engines, but sometimes there is a bit of pressure in the fuel injection distributor that leaks down into the inlets on the heads. My batteries were marginal so I propped it through a couple of blades and BAM! That engine propped itself through a couple of blades I was propping it the right way with the tips of my fingers and body position in the safe zone, but none of that mattered as far as scaring the crap out of me. Just like trailer brakes all it takes is one broken wire to ruin your day.
The 12V 71 That would not shut down had a relay with fused Contacts sending power to the Fuel solenoid. When the relay was pulled and as I opened the fuel lines it shut down. Did rebuild both blowers and unit ran okay afterwards. The speed did not go too much above 2000 rpm but could have. Thinking very fast as it happened. Simon C
In my early days as a mechanic I worked for a crane and rigging company. The upper in an old P&H had a 6v53 that was a constant problem. Their decision was to repower with a 6-71 out of an old truck. We drug the chassis up by the shop, checked fluids etc. 5 gallon can of fuel and some batteries were setup for a test fire. It must have been a slow day because there were 5-6 operators and riggers standing around when we spun it over. Coughed a time or two and once it got the air bled out she was a moonshot! WFO, fan going 90 to nothin, belts shredding, chunks of the fiberglass hood flying off, wasps coming out of their nests wondering *** just happened. Riggers and operators scattered like a squirrel being chased by a dog. The old shop foreman pulls his smokes out, lights one up and watches it for 10-15 seconds and makes a motion to me like he was pulling the fuel hose out so that’s what I did. When it finally ran out of fuel it sounded like a tornado siren winding down. I was so captivated by what was happening I didn’t move a muscle. I was covered in dirt, chunks of belt and fiberglass. It was one of the coolest things I’d ever seen! After it got quiet Bill took another drag and said grab your tools kid, let’s pull it out. I’d say it’s a good one.
First was at Nashville Diesel College. One group did something wrong and they had a screaming Detroit. Everyone fled but the instructor. I watched around the corner of the bay door as he cut the fuel line and walked away. Second was a BC1 Cummings. Did an engine swap and it ran away. Put a 1/4 steel plate over the turbo and it kept screaming for a while. This happened 2 or 3 times. Finally figured out a dirt dobber had stopped up the fuel return line. Third was a Mack. Turbo went out and was towed in. Asked the company if they wanted to pressure wash the CAC out, take it to a radiator shop or replace it. No just replace the turbo. Started it up and away she went. Ran for several minutes with the stop cable pulled running on oil from the cooler. When the RPM's got really high the valves would float and slow it down for awhile. Then take off again. The one before first was a primative skid steer type machine. It was very narrow. I did not follow directions and had the bucket up while traveling. It turned over on its side. Ran away from the oil bath air filter. I got that apart and shut down PDQ. There were some others along the way but they were low pressure as shut down quickly.
Actually any kind of inert gas would work to shut one down. As well as very carefully administered H2o, only in extreme emergency of course, would be easy to over do it and hydro lock.
Something I forgot to mention. If you are on a Detroit, you should fear a runaway every single time and be prepped for it. I always have a pair of vise grips already adjusted and ready to clamp a fuel line, a hammer in case the vise grips aren't enough, and most the time if I can get a/the valve cover off, I have a pair of vise grips on the fuel rack tube. 1 or a combination of these will get one shut down pretty quick. I don't trust the emergency flaps, never have. If you have a engine that has the flap, make sure it works BEFORE you start! I have seen many of them wired open and not usable.
The place i worked had alot of Detroits i was told about them so i was very careful and never had a problem. There was a older guy i know that had worked on some kind of stand by engines that were under ground. He said he would have the intake hose off and a big book ready. One started running away he sat the book on the intake and it started eating it so he got clear and let it go.
Actually, any time I work on an injection pump or governor on any engine, I always pull off the air intake hose at the engine and have a piece of 1/4” steel plate ready to slap over the intake if the need arises.
Forget who told us about it but many many years back we had a pair of 1/4 inch steel plates made up with handles welded to them so if the need came you could slap them on the intake without having to worry about getting fingers trapped between plate and intake. Would not like to think about getting fingers caught and not be able to get away from a screaming 16V-71 or D399 Cat!. We needed two as many of our engines had twin turbos or blowers. In 40+ years don't think I ever needed to use them, but still felt better knowing they were there!
Very few instances with runaways, I can attribute that to electronically controlled fuel systems and facility engineering. I was working on alternative fuel development. I was the one operating the test unit and performing hardware changes. Well I was needed else where that morning. I left it to the engineer to give the replacement operator a lowdown on how to meter alternative gaseous fuel, in addition to all other engine control parameters. Development on this was a knife edge, give and take, boundary limit testing scenario. The replacement guy did a great job until it was time to shut the gaseous fuel off. Normally setting a "0" to the parameter would bring the system back to original maps, that was the case with all the engine parameters except the gas valve. "0" translated into the valve not knowing what to do, so it went wide the fudge open. The engine was at rated power conditions when this happened and monster slug of hydro carbons enters the combustion chamber. Away we go. Hit the big red button. The facility components were enough to suffocate her and bring the angry beast to a standstill. Needed new lower rotating components, liners, head gaskets, spacer plates. The operator apologized to me so many times, It wasn't his fault. I've got another one from a co-worker that i could butcher if anyone is interested. Hopefully i don't get a call saying I violated some confidentiality agreement I signed years ago.
I know of an outfit near by that in the past has done CNG testing, but mostly on EMD engines. That would be a fun one to deal with in a runaway condition. I would want a huge bank of Co2 and individual inlet port distribution for peace of mind, and to save the engine and the building in case something goes wrong. I think the only way to violate confidentiality is to explain all the technical working parts of the system. You may actually find that they disclosed much of what you did either for patents or at a big expo meeting of the minds etc. especially if it was 5 or more years ago. If they have a website look on that and see if and what they may have disclosed there. I'd like to hear more stories of that sort of work.
An old Co-Worker's experience that was pretty infamous in the shop Just like anything else engine development was a different world years ago when this happened. We learned from mistakes, this being one of them. There was a test facility where the operator's console was in a mezzanine above the engine, you would have to walk past the test bed to exit the building. Back then you would walk next to a screaming stationary engine without a second thought, still do in most of the world I imagine. The console was populated with an operator and engineers running the test. The facility had emergency shutoffs tied in to E-Stops. Intake air, exhaust and fuel would be shutoff, obviously that works well and great for controllable engines. The 8 cylinder engine being tested was the largest bore we traditionally run - 280mm or about 11", its about the size of a medium/smaller box truck. The engine has a rear mounted turbo and it has a huge oil sump 200~ gallons. This application was using a drive line coupling between the engine and the dyno. To contain the coupling there is guarding in place as you would expect. The coupling failed causing a sort of violent mechanical windmill effect. As the coupling was making its rounds it mangled the coupling guard, smashed the turbo oil supply, and the intake manifold. The turbo oil supply was then feeding the inlet manifold making the e-stop irrelevant. The operators console was full of engineers collectively soiling themselves weighing the option of staying put above the engine or running past the self-destructive violent rotating mass to exit. I am pretty sure they decided to stay put.
Just remembered a dumb thing I did once, okay sure I have done many over last 71+ years, but this one is on topic! Was tasked with replacing the injectors in a Euclid R-35 with a 12V-71. Job went pretty good till the point I went to fire it up. Pushed in the shut down cable and hit the starter button. If you're smart you know right off what I did wrong! Yep this dummy adjusted the rack with the shut down pulled out! Only thing that saved me and that engine was the emergency shut sown cable was not seized and the flappers on the top of the blowers were functional as opposed to my brain! Managed to kill it before RPMs got too high and proceeded to run the rack adjustment a second time this time with shut down cable in the run position.
A long long time ago, on one of my first days of driving a dump truck I showed up at a construction site and no one was around. It was before cell phones and I was about to leave when a service truck came flying up and the operator jumped into the excavator and fired it up. I backed into position and he immediately grabbed a full bucket of clay. I think it might have stalled out and began to run backwards. The operator stated screaming and running for his tools. White smoke was filling the air drawing crowds of onlookers. He took the fuel line off and It continued to scream, running on crankcase oil? He franticly tried everything he could think of to shut it down, as a young pup (me) looked on with eyes wide open. It finally seized up and I slipped away in my truck.
Forgot about the Ford P/U with a 6.9 diesel. Four year employee replaced the electric solenoid in top of the pump. He put it together incorrectly and off she went. Everyone scattered and I hammered a fitting on the fuel filter when I got there. Employee backed his truck to the door. Loaded his tool box and left. Owner was standing there with his mouth open. He was an older retired man with a nice RV hauler. Had an OD unit on the back of the auto trans. I had put that on and changed the diff gears. What do you do then? I am sorry and I will fix it. Engine did not sling a rod but a piston had come apart. Block was bad. That was expensive. One of the joys of owning your own business. Make all the money in the world. Take off anytime you want. Do not have to answer to anyone.
Yeah many of these stories, are scary, and add new light to the term unintended acceleration. Years ago even after my ordeal, the only time I ever thought of a runaway was after working on the injection system or governor and maybe a fresh start after overhaul, about all I had for a just in case was a piece of 1/2 or 3/8 plywood, or maybe a 2x6. It never even came to mind out on a job site operating though. I guess many of us have been lucky so far anyway. I'd say if it ever happens and you don't have a way to shut it down fast, try to stay away from the flywheel, and balancer or damper. Keep em coming, some interesting experiences you all have had.
Many moons ago when I started wrenching on big trucks all of those old cabover CF trucks had 903 cummins or the infamous chassis lubricating 6v92's..We had 4 steel plates mounted to the wall next to the fire extinguishers throughout the shop in case of emergency..I witnessed 2 6v92's go ape$hit and nobody even glanced at the plates..By the time we would have jacked up the cab to get at the engine nobody was gonna crawl in there anyway...Pushed both out into the yard and watched them self destruct..ticca ticca, knocka knocka, BOOM...