[QUOTE=Reagy;46827757]Best things are to damage something non-vital if it means stopping it, replacing a turbo is easier and cheaper than a full engine rebuild or swap.
Something else you can do when a diesel does a runaway while you're actually moving is to put it into high gear and ride the brakes, put as much stress as you can on the engine and it'll eventually stall its self under the stress. Sure you might have a fucked flywheel, brakes or gearbox in the end but better than the engine going if you ask me.[/QUOTE]
I guess if all else fails but both are pretty big budget repairs, I really wouldn't suggest it with big high torque diesels though. Maybe with a smaller car or truck but on a semi (or lorry) or large truck chances are even in higher gears it will do a shit ton of damage to the drive line, crack motor mounts, sheer axles, etc... Also seems dangerous if you are in traffic and it gets away from you.
All I've seen since I got myself a diesel car is runaway videos all over Facebook and Youtube. Seeing all these videos has given me nightmares.
Holy shit, I have a 2003 diesel car and after reading this thread I'm not so sure I'll ever feel comfortable in my car again.
I toured the Norfolk Southern locomotive shop in Roanoke earlier this year and they were just pulling the engine out of an SD70ACE that had runaway, a situation very much like this I'm told. It was pretty brutal, actually. We got to look inside and there were fragments of turbocharger embedded 3 inches into the cast iron block, as well as hundreds of holes in the actual carbody of the engine where bits of turbo had shot out. They said that 80% of the engine was a loss, except for the block, which could actually be used to patch other blocks. The Roanoke plant is pretty amazing in their ability to recycle engines that other service shops would scrap.
[QUOTE=Unreliable;46826996]those guys in the second video look like the gnarliest motherfuckers ever. I'd be scared shitless to have that job, let alone hold on to a diesel going ham like that.[/QUOTE]
Well these guys are passionate about this. That engine was the original engine out of a boat almost 100 years old, and they didn't want to lose it.
So they risked themselves to save, what some would see as, a chunk of metal.
[QUOTE=Reagy;46827757]Best things are to damage something non-vital if it means stopping it, replacing a turbo is easier and cheaper than a full engine rebuild or swap.
Something else you can do when a diesel does a runaway while you're actually moving is to put it into high gear and ride the brakes, put as much stress as you can on the engine and it'll eventually stall its self under the stress. Sure you might have a fucked flywheel, brakes or gearbox in the end but better than the engine going if you ask me.[/QUOTE]
I guess a fire extinguisher would be the best thing to have at hand.
Why not make the best of it? Since the engine's gonna be ruined anyway, might as well leave it in gear and go bollocking down to the destination. So instead of sitting where you are with a blown engine, haul ass to the destination with a blown engine! :dance:
[QUOTE=Chinook249;46829630]Why not make the best of it? Since the engine's gonna be ruined anyway, might as well leave it in gear and go bollocking down to the destination. So instead of sitting where you are with a blown engine, haul ass to the destination with a blown engine! :dance:[/QUOTE]
Yeah and possibly risk a even more costly and maybe even more deadlier accident because who knows there might be another train further up those tracks and as the video shows, it took a while for that train to come to a complete halt.
As a mechanic, the fear of a runaway is why I refuse to work on any older diesel engines. Not only do I not want to be confronted with the demonic noise they make, I don't want to be responsible for ruining a classic motor.
[QUOTE=Grenadiac;46830103]The fear of a runaway is why I refuse to work on any older diesel engines. Not only do I not want to be confronted with the demonic noise they make, I don't want to be responsible for ruining a classic motor.[/QUOTE]
Runaways are far less scary if you are aware they could happen and come prepared, in that video above with that old GMC the main cause of the problem was the younger guys kind of panicked and left it up to the old man to figure it out. Granted they should have had something more than a plastic lid to choke the engine. A small piece of plywood or 2x6 will stop most engines if it makes a good enough seal against the intake.
In any case someone is gonna have to start it and they may not know what a runaway is and it will most likely cause them to panic. At least you know what it is and how to stop it.
That's true but it just seems terrifyingly common with diesel engines older than 30 or so years, especially ones that have been sitting and truly I don't know what steps to take to prevent it in the first place.
[QUOTE=Grenadiac;46830365]That's true but it just seems terrifyingly common with diesel engines older than 30 or so years, especially ones that have been sitting and truly I don't know what steps to take to prevent it in the first place.[/QUOTE]
There really isn't a way to know till you try, but if you know the engine (which you should if you are working on it) then you will be fine.
even when i'm working on gasoline engines that require any kind of intake/fuel work, I keep an old t-shirt next to me so I can jam it in. Obviously not caused the same way a diesel one is, if a linkage or something is caught, or mixture screws aren't right they can rev out.
I used to have an old chevy truck with a newer crate motor. I didn't know when I bought it but the fucking thing had a super high compression (I thought it was just a regular old 350, but it ended up being one of the racing crate engines). If I didn't run shell premium in it, the damn thing would diesel (keep running even after I turned off the spark) until I put it in gear. The first couple times it happened I panicked. It didn't run hot or anything, I still don't know why a gasoline engine would diesel.
[QUOTE=Nazereth666;46827739]Yeah I had a friend who had his truck runaway on him, it's surprising how many diesel owners don't know about it. He went to go start it outside of the cab and it went off, causing him to panic and runaway himself haha. He called me because he had no clue what was going on and I could hear it in the background buzzing away. I told him to get a rag and shove it into the intake and he preceded to and it did stop but it had already ruined the engine by that point. We ended up just doing an engine swap and after pulling out the old engine and inspecting it it had spun the crank bearings, roasted the piston rings and scored most of the pistons and their cylinders.
It was a mess, and had he known what to do he could have saved the engine. Some cars are equipped with a valve that will stop the engine from sucking in air but on a lot of cars you have to shove a fire extinguisher in the intake to starve it of oxygen or grab a board or rag and stuff it in there kind of like this guy below.
[video=youtube;3NRaqgab0_w]http://www.youtube.com/watch?v=3NRaqgab0_w[/video]
He seemed kind of prepared for it to happen and while the turbo was destroyed he saved the engine.[/QUOTE]
This guy is begging to get a darwin award for wearing that shirt working around that engine.
Hope it doesn't hit any orphanages, cat stores, or kitten orphanages!
Imagine if this started happening while you were unlucky enough to be on the highway.
Even if you can get it into a place where you can slow down and stop, that shit's gotta be terrifying. Like out of nowhere your engine starts revving like mad and you start speeding up and you can't figure out why. If you have no idea what's going on and panic, that can create one nasty situation.
[QUOTE=Reagy;46826055]Runaways are the most scary things to happen to a diesel engine, especially with more modern turbo diesels in cars. It's near impossible to figure out how to kill unless you know exactly where the cutoffs are and most of the time they ain't obvious, never mind the issues with drive by wire systems which can completely fuck up fuel control and again cause a runaway.
I've seen someone have to resort to cutting the fuel line to stop theirs once because he couldn't find the air or fuel cut off valves, and the turbo would have attempted to eat anything you shoved over the intake.[/QUOTE]
Even worse when the runaway is caused by the turbo leaking oil into the intake tract. When that happens cutting the main fuel supply doesn't really do a damn thing, as diesel engines will run quite happily on their own lubricant. Only way they shut off like that is if you flood the intake with non-flammable gases(Passenger car engines are small enough that a CO2 fire extinguisher will do the trick) or wait until it runs out of oil and explodes.
[QUOTE=TestECull;46834940]Even worse when the runaway is caused by the turbo leaking oil into the intake tract. When that happens cutting the main fuel supply doesn't really do a damn thing, as diesel engines will run quite happily on their own lubricant. Only way they shut off like that is if you flood the intake with non-flammable gases(Passenger car engines are small enough that a CO2 fire extinguisher will do the trick) or wait until it runs out of oil and explodes.[/QUOTE]
Alternatively just shove a rag into the turbo forcing it to lockup. :v:
Shouldn't there be some sort of automatic system to prevent runaway engines like that? Seems like the best method right now is tossing an old sock into the turbo.
[QUOTE=Fatfatfatty;46835243]Shouldn't there be some sort of automatic system to prevent runaway engines like that? Seems like the best method right now is tossing an old sock into the turbo.[/QUOTE]
Modern engines normally have automatic switches which will kill the airflow and fuel lines automatically but when the electronic system controlling those fails or those two sources are not the cause (eg. turbo leaking oil), it don't do shit.
When a train engine that makes, you know, 10000 ftlbs of torque starts losing its shit there isn't much you can do.
Just thank god trains are diesel-electric. If there was any physical connection between the engine and the wheels, THAT would be scary.
Imagine seeing a train, at night, speeding down a track at like 100 mph with flames shooting out of the exhaust.
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