what to do and what not to do when a engine runs on its own?

[earthscratcher]

just had my first run away but it was a small 30hp, I remember a guy at the quarry had a 3406 run away on some type of crusher plant,he tried to get it shut down, but it blew up before he could, he died on the spot . what to do ? and when to run and when to not run? could a smaller engine kill to?

 

[JD955SC]

You can go try to kill a runaway all you want. Me, I’ll be leaving the area if it can’t be shut down right away.

Anything can kill in this business especially when it starts slinging parts around.

 

[Truck Shop]

Let this one roll to see what kind/type of reply's it receives.

 

[cfherrman]

My first runaway was on my own equipment and plugged the intake that limited the rpm then spun the suction fuel filter off to shut it down. I doubt it got very high rpm but there was a lot of black smoke. It was mine and I was broke so I was going to save that one or die.

 

[thepumpguysc]

I worked next to a Mack Dealership for YEARS..
I would always get “Mack pumps” in with the brass inlet fitting knocked off flush w the aluminum hsg..??
I finally asked, what’s up with that.??
THATS HOW they stopped a run-away.!!!
I toldm a 3/4 wrench works just the same.!!! (Remove the line)
After that little talk, I retired my EZ-Outs..

 

[thepumpguysc]

I can’t count how many I stopped.

 

[skyking1]

If it's a lube oil runaway, you need to stop the intake of air. Too many conditions and situations to enumerate a procedure that fits.
I hotrodded a VW TDI once, and part of that was removing the ASV valve which cut off the air when you keyed off.
It had a funky intercooler that could "store" a little blowby lube oil and every once in a while it made a halfhearted little uncommanded blurb and puff of smoke.
I drilled a small hole at the low point and would fish it with a wire, end of that. It was a tiny boost leak
I learned about the ASV when my wife's car refused to start. It was also in the path of the EGR and they get stuck with gunk. A quick cleaning and it was good to go and still runs for a friend we sold it to.

 

[Mike L]

Had a small duetz run away on me. It ran for probably 2-3 minutes at full screech but wouldn’t blow up. Finally I got brave and cut the fuel line.

 

[Joe H]

Long ago, 53 Chevy 6 cyl with a brick on the throttle. Ran a long time and then just kinda wheezed to a stop.

Quite disappointing, wasn't the show we had hoped for.

Joe H

 

[92U 3406]

Anything mechanical that has not run in a while or a new overhaul I always leave the turbo inlet open and have a paddle handy.

If something runs away on me I'm letting it ride. Nobody's iron, or even my job, is worth the risk IMO. I wouldn't expect anyone to risk their neck to save my iron either.

 

[IceHole]

Had a small duetz run away on me. It ran for probably 2-3 minutes at full screech but wouldn’t blow up. Finally I got brave and cut the fuel line.

Cutting fuel isn't stopping a runaway.

 

[cfherrman]

Works on a two stroke stuck at full fuel

 

[Truck Shop]

Wow----serious stuff.-------------I never worked anywhere that it was stated a employee {should}
be a hero--for a inanimate object.

 

[chidog]

My runaway was a D353 in a D9G. No big deal at all and not at all life threatening, just crank the compression release lever and it stops.

Never had the chance but wonder if the jakes would do the same?

Seen some video's of idiots trying to destroy a Detroit they seem to take the overspeed just fine and not fling parts, just slow down from the excess heat etc.

Had a friend that lost a leg in an oil field runaway, a clutch blew.

 

[Coaldust]

C02 fire extinguishers work fairly well depending upon displacement. One Cat dealership I worked for had a strict policy about it. Any fuel system or turbo charger required an emergency shut down plan & prep.

 

[Junkyard]

I’ve only had a 6-71 runaway on me. One we pulled out of the weeds to be checked out for a repower. I just pulled the fuel hose out of the 5 gallon jug I was using. I’ve yet to see one violently self destruct in person but I know it’s a real thing. Anything I’ve ever started fresh I always leave a way to snuff it out but I’d also stand back and let one scatter itself if I couldn’t safely (reasonably anyway) somehow shut it down.

 

[aighead]

I'm ignorant in such things... What in the world are you guys talking about? A machine won't turn off and increases in RPM until some of them explode? I think I can safely assume that cutting power to the machine not working is a cause but I don't understand why that would happen? I guess like a old-school crank car or tractor it is creating it's own power?

 

[JD955SC]

I'm ignorant in such things... What in the world are you guys talking about? A machine won't turn off and increases in RPM until some of them explode? I think I can safely assume that cutting power to the machine not working is a cause but I don't understand why that would happen? I guess like a old-school crank car or tractor it is creating it's own power?

Diesel engine runaway. So normally diesel engine speed is controlled (and limited) to its normal operating range by the governor, which automatically controls the supply of fuel to the engine’s injectors. In a runaway situation the normal governor control is not in effect. Can be for a number of reasons, often a result of a governor or fuel system malfunction. Two stroke detroits were especially famous for it when the rack would stick or not be set correctly.

A diesel engine can also runaway if the engine oil becomes its fuel supply as well. Cutting the diesel fuel supply in that case may be very well not stop it

A rarer type of runaway is if another fuel source is inhaled by the engine. The Texas City refinery explosion is thought to have been caused by a runaway engine in a truck running on refinery gasses

The usual method of a stopping a runaway is to kill the air supply. A shutdown flapper or holding a metal plate over a turbo inlet, or even discharging a CO2 extinguisher are three popular methods. Removing the fuel supply is another method, such as closing a supply valve or beating a fuel filter off with a hammer

The good news about runaways is that in this day and age of electronically managed engines they are much rarer

 

[cfherrman]

Mechanical injectors have a range of no fuel to full fuel and the governor will pull them back to limit rpm, if that doesn't happen typically because the rack gets stuck it's a runaway and the engine rpms will go 4000+ till something breaks.

A common engine oil runaway is a failed turbo seal causing the engine to drink it's own oil. If you ever buy an aftermarket air filter dont buy one with bolts so you can take it off and clog the intake with rags.

Natural gas will run away the engine and you can't stop it unless you choke the intake, in the oilfield we will shut the engines off then bleed off gas.

I have also given a minor runaway by cleaning with gasoline by the air intake, the gas fumes will raise the rpms quite a lot.

 

[56wrench]

Any diesel engines working in the oilpatch have to have a positive air shut-down valve . Roda-Deaco seem to be the popular ones here. I would assume that applies to NG or LPG engines too