Runaway: How common is it??
 

So with all the posts lately about diesel runaway, how common is it really? Or put another way, how many of you had it happen and what did you do to save the motor (if it was saved)

Glenn

It is a very rare occurence. With good maintainance and a good idea of what you are doing it should never happen. Wrongly installed linkage can do it, and bad turbo seals can do it. People sometime cause a short runaway by leaving the wrong fuel in the intake system. But a "real" runaway consists of the engine consuming crankcase lubricating oil. Doesn't happen very often, most operators couldn't make it happen.

It's rare, I'm 50 and I have seen three in total.

They are like air accidents though, rare, but nasty enough when they happen they get a bad rep.

I've personally seen the aftermath of two. One was a 77 300D that I bought that the previous owner blew up. The other was a VW Jetta TDI that the dealer did some turbo work on and then it ran away, and they blamed biodiesel. I've never seen one in person.

I've only read a few threads here were it actually happened to someone. Like stated above, when it happens it's catastrophic.

Well, I have a Jetta TDI and a 300D, so I am a bit concerned. I'll just keep an eye on any oil consumption and strange occurances

If they ever do run away. You have to block the air intake. You'll want a block of wood or something like that to block the air.

Performing work to the IP or turbo can exponentially increase the chances of your diesel running away by chance. Much of the anecdotal evidence and stories on this site are after someone had been tinkering with the fuel supply, just reinstalled IP, etc. Normally with no modification to these parts it is very very rare.

I have never seen one happen. Blocking off the air intake is good. BUT, by the time you realize what is happening, find the wrench to remove the intake hose, locate a block of wood. It`s going to be too late, and I would think you better find something to hide behind before it grinades.

Having a CO-2 fire extinguisher close by will work also, from what I have read.

Charlie

This (first link) is a NICE and SAFE runaway, in that it didn't actually explode, a proper runaway explodes, which looks more like the second link, but more violent....

http://www.youtube.com/watch?v=5zx3qKX_Pno

http://www.youtube.com/watch?v=wIbpiihHQ-g

Proper runaway huh? To me a proper runnaway is one you can stop. It happened to me once when the IP shaft seal leaked fuel into the crankcase cauing the level to rise to the point of fuel/crankcase oil injection took place via the rings. I almost crashed but was able to stall the engine quickly before it destroyed itself. It was a scary experience when the car accelerates full throttle on its own and shutting the key off does nothing. Thank God it was a manual transmission.

Shift up and stall a manual, or select neutral on an automatic, stop and get out in case the TC lights off or flywheel fails. No one who makes the news on unintended acceleration seems to remember neutral.

Never had it happen to me in a MB.
Had it 2X with a Detroit 2 stroke. They have a butterfly in the air inlet to shut it down when it happens. if you are not fooling with you fuel & air inlet (turbo) its very unlikely to happen. far less likely than being T-boned by some one sending a text.

It happened to my 87 300 SDL as the result of putting the vacuum shut off valve in wrong. Broke the pump, and engine ranaway for a good 2 minutes. I finally shut it off by ripping the main fuel line off.... Let's say the adrenaline was flowing. The result was a broken injection Pump and a cracked head or head gasket (a result from the heat built up from the ridiculous revving going on) this car now sits outside my home. It was a very scary experience to say the least.

Happened to me in a VW diesel Rabbit. Luckily a stick shift so I could downshift and keep the speed low. I managed to stall it out by standing on the brakes.

Twice
 

On the same car, an '82 SD.

I had a used motor put in and the morons at the shop disregarded my instructions to remove all the linkages and the vacuum box off the old motor (with everything correctly set up) and put them onto the new. (They then junked the old motor before I could rectify.)

They made a complete dog's breakfast of the linkages on the 'new' motor. While trying to sort out I discovered that if you pulled too hard on the throttle linkage, at the pump, it could snap over to wide open. Believe it or not they had managed to install a spring into the linkages that would pull the arm over, if yanked just so.

The first time this happened I was in park, fiddling with the linkages and it took me a sec or two to react and kill it. Scared the bejeezus out of me.

I THOUGHT I had it sorted out.

Months later in monsoon rains I got cut off so badly I almost had to take the ditch. In total PO'd mode I stomped on the throttle to get off the shoulder and then realized it had jammed wide open. Tried to brake but it was overcoming the brakes -- plus I was into mild acquaplane and approaching an intersection.

I put it into neutral for a sec or two, just enough to brake and get back onto the shoulder but didn't think to immediately turn off the fuel. With it going full runaway I jammed it back into D and turned off the key. WHat then followed:

1. The tranny made noises you never, ever want to hear.
2. The engine wound down (seemed like an eternity).
3. Miraculously, tranny was fine afterwards.
4. For two weeks, ran normally.
5. Then started to burn oil... and more oil and more.
6. About two months later was running on four cylinders and burning half a litre of oil daily.

Not my finest moment.