Printable View
Truck runaway engine.
<video controls autoplay loop> <source src="https://diqn32j8nouaz.cloudfront.net/runaway_engine_billowing_smoke_tt.mp4" type="video/mp4"> Your browser does not support the video tag. </video>
Previously:
https://www.homemadetools.net/forum/...128#post187935
https://www.homemadetools.net/forum/...441#post204896
https://www.homemadetools.net/forum/...648#post216187
https://www.homemadetools.net/forum/...6845#post84468
https://www.homemadetools.net/forum/...125#post125967
so what is this video showing? apart from the belching smoke, what is the issue?
The engine is peak revving and can’t be shut down. The smoke indicates it’s being fuelled by something other than it’s usual source.Quote:
Originally Posted by desbromilow
As per the description...the motor is stuck on throttle.Quote:
Originally Posted by desbromilow
Someone has sound turned Off......Quote:
Originally Posted by desbromilow
Runaways often fix the problem, without wasting a lot of fuel.
On the old Continental LDS 427 180 HP multifuel engines in the M35s there was a setting to limit the throttle movement for running anything from peanut oil diesel mix to straight Av gas.
At the 64 C wheeled vehicle training battalion where I worked in the motor pool. one of the trucks had been filled with av gas to demonstrate it could be done but didn't know about having to reset the pump. after driving it around for a while the trainee stabbed the throttle to see it smoke when he did it stuck the tach went past red line his instructor tried to switch it off but nothing happened, he raised the hood managed to knock the fuel line off the pump but by then the turbo was already turning red he said. they jerked the breather hose off and slammed a logbook against the hole. it sucked it in like it was air that engine ran until it had sucked all of the oil out of the pan before grenade Ing .
The most common issue with run aways is a bad turbo charger. The shaft and seals wear out and engine oil is drawn into the intake side so there is no control. It will go until its out of oil or it blows up. If you can get to the air intake you can choke with a steel plate or wood. By that time its to late. Time for a rebuild. Old Detroit diesels had a flap that would close to prevent that from happening.
Saw a big dozer have a runaway once. Seals in the turbo went bad started pumping motor oil into intake. Blowing the thickest black smoke I have ever seen. Driver did his best to kill the engine digging the blade into the ground. Thing just kept pushing, pushing until the grousers broke traction working like dual trenches. Then a Big Bang then silence, as smoke began escaping from the massive hole in the side of the engine.
One shop I worked at I was replacing a turbo on a full size city bus. You need to clean out the air charge system to remove any oil. I was in the process of removing the charge air cooler when the boss came up and asked how much longer. I responded it will be done after lunch. I'm flushing the cooler. He said I need it now, just put it back together and drive it and it will clean itself. Being young and dumb that's what I did. Lucky for me the road we were on was in a commercial area. As soon as I turned out of the lot it was like I turned on a 1000hp nitrous system. Thick smoke everywhere. It accelerated three times as fast as it normally would have. I had one heck of a ride for about an 1/8 mile. I swear I bent the brake pedal trying to stop. Was I pissed. From that point on I did not listen to that guy. He thought it was funny. I almost had to visit the men's room to change my shorts. :flame:
I don't have any experience with a runaway diesel, but I always wondered why they don't just shut off the fuel and maybe, block the air intake. I've seen a lot of these where folks either intentionally or accidentally grenaded a diesel, and it's quite the sight!
Runaway diesels are caused when there is an alternative source of fuel. Most commonly bad bearing in a turbo pumping engine oil into the intake. Shutting fuel off does no good as there no way to shut off the alternating fuel. The air intake on most diesels is typically not easily accessible. In addition, when it happens most people freak out as it is a scary situation. It is also very risky to even be close to an exploding engine.Quote:
Originally Posted by schuylergrace
There are emergency shut-offs systems available, which shut off intake air, but again, the vast majority of diesel powered devices do not have one installed.
One example;
Attachment 44788
I hadn't thought about that, even though several folks mentioned the turbo bearing oil being a cause. I always assumed something malfunctioned to allow the primary fuel to go into the engine unregulated. But my only real experience with diesels is with our old International Harvester tractors back home. They prolly would have died if somebody got near them with a turbo!Quote:
Originally Posted by hemmjo
Thank you for the elucidation!
Sometimes the fuel is off and the engine is running on crankcase oil, your right about blocking the air flow. Hopefully you can access the intake before it destroys itself. Most diesels are low rpm's, when it runs away rpm's can double what its rated for so parts will break. The boss will not be happy.
