A good sized fire extinguisher is a good idea on any vehicle. Fires after collisions are common and it's not impossible for a diesel to catch fire from a serious fuel leak. You won't be able tu shut off a Benz with the key if you have a fire under the hood until the fire is out -- the vac lines will melt.

A quick squirt with a fire extinguisher can save a life.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

If it's running away with diesel fuel and not crankcase oil, here's the definitive proof that cutting or removing the fuel line will stop the engine within seconds:
1985 TD /none starting

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I was taught to feed shop rags into the air intake of a runaway diesel to stop it. I have never seen one runaway and never seen one stopped so I don't know if it works. I am sure that would be my my first reaction. If no shoprags are around, your shirt, pants etc may also work.

I also cannot stess how strongly I believe in fire extinguishers. I think everyone should have them and be trained to use them.

That's very true, but you have to cut the one from fuel filter to IP and not the one from tank to fuel filter. Cut the one between tank & filter and it might have enough fuel to self destruct, if you were delayed in cutting.

Diesel requires fuel or air supply shut off to stop. In some larger diesels, such as those found aboard large ships, used for electrical generation, can suck intake gaskets and head gaskets when air supply has been suddenly blocked. I've seen the results of this happening aboard a ship once, and the big Cat sucked it's head gasket and suffered major damage. Also shirts and rags can have the same effect, that's why any good diesel shop will have CO2 bottles by every work bay for this reason.

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

Several times in cases of runaway engines I've read if my car were a standard I could just put it in gear and kill the engine. Too bad I've got an automatic.

Unless I am off my rocker, shouldn't an automatic in Drive with the brake on kill the engine just as easily. I mean certainly if your transmission isn't in good shape you could damage it.

I mean a torque converter has a stall rating for a reason. Isn't that supposed to be the amount of torque that can be applied to it before it stalls the engine?

I say this because I have
a) never had a runaway engine
b) never stalled my engine with an automatic transmission in drive with my foot on the brake.

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'84 300CD Turbo 132k (Anthracite Grey) - WVO - My daily driver - Recently named coo-coo-coupe by my daughter.
'84 300D Turbo 240k (Anthracite Grey) - Garage Queen
'83 300D Turbo 220k (Orient Red) - WVO - Wifes daily driver

I'm not a certified mechanic, but I did stay at a HolidayInn Express last night.

Not stall it, but with a heavily applied brake, it'd bog it down. But unless you have someone else to help cut fuel, etc. You'd either have to sit there until the trans gave up or you ran out of fuel. Guess which one's most likely.

Yes that requires a manual trans to do the stall by trans, and you need to be behind the wheel driving the car when it happens. Don't do that in your garage, you might end up in the living room. Don't try it with an autoloader, you'll be out double.

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

James,

That would be quite a jolt when the automatic transmission (AT) went into gear with the engine running overspeed. And unlike a manual transmission where you would select the highest gear and slip the clutch, the AT would go into the lowest gear and put an extremly high torque on the drive train.

The AT would not stop the engine but it would slow it down if everything survived the initial jolt. The transmission fluid in the torque converter (TC) would get very hot quickly because all the energy from the engine would be converter to heat in the TC. It would be the same as applying the brake and the accelerator at the same with the AT in gear. The engine would run faster than idle under load but it won't stall.

The stall rating of a TC is between the input and output of the TC not when it will stall the engine. A TC will not stall an engine because it is designed that when the engine is at idle speed, the TC puts practically no load on the engine.

P E H

TwitchKitty do not stuff rags into a run away diesel, a big one with a turbo will just suck them threw and spit them out. You would probably ruin the valve train on a n/a MB like a 240D for example. Not to mention it wouldn't shut it down. So far a Co2 seems to be the way to go!

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Being aware and prepared for the possibility of a run away saved my motor.

Good job!

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79 240D (no name yet) 203K Miles Maple Yellow
98 2500 4x4 HD Dodge 24 Valve Cummins TD
83 Chevy Van (Dead-Trans. shot)

What happened?

Yes please do tell. We need interesting storys up here with the snow while sitting in front of the computer screen with feet up and a glass of hot coco.

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Adam Lumsden
(83) 300D
Vice-President of the MBCA International Stars Section

Here is the post.

Run away 240D engine, very scary!

I still have serious concerns with the installation of my shut-off on the IP. The hook on the shut-off valve is not hooked into the notch on the rack in the IP. It is behind it. When the hook was in the notch, I got a run away. I think the missing spring on my throttle linkage at the firewall is part of the issue. There should be 2 and I only have one. I think the return force on the linkage is sub-par and the new shut-off valve was a bit stiff. I checked the operation of the new shut-off before installation with the Mighty-Vac and all appeared well. I am still confused as to why I had the run away.

After I get the rear window seal project done I will readdress the shut-off valve and spring issue.

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79 240D (no name yet) 203K Miles Maple Yellow
98 2500 4x4 HD Dodge 24 Valve Cummins TD
83 Chevy Van (Dead-Trans. shot)

My wife told me her 300TD took off with a huge trail of black smoke while driving down the highway and wouldn't stop by turning off the key. It eventually went back to normal after a minute or so. The car had been having vacuum problems for a few days....not shutting off, gear changes, no central locking, hard brakes etc... I had a look and saw sump oil dripping from the air cleaner housing. I started it up and was checking for vacuum when the engine ran-away. It just went flat out and black smoke went everywhere....very frightening when you're leaning over the motor. I quickly figured that the motor was consuming it's own crankcase oil, fed in via the air intake. I pulled the hose out of the top of the air cleaner, I could see black oil in it when it is normally white. The engine slowed down to normal. Black oil was comming out of the vacuum pump down the pressure "input" side which feeds into the top of the air cleaner. The diaphram had failed in the vacuum pump letting engine oil through. We washed out the air cleaner housing, fitted a new filter, got the pump repaired and everything was right again. Well almost. The brake booster failed within a few weeks due to engine oil on it's diaphram. We fitted a 'new' one from the wreckers. I don't know why the engine went back to normal when this happened previously while my wife was driving, maybe the torn vacuum diaphram was only occasionally leaking oil. I guess we were lucky that time.

Andrew,
What vacuum pumps are in your 300Ds?
If this were to happen while driving, what do you recommend doing?
1. Stomp on brakes and stop the car?
2. Keep car in gear and drive it slowly to garage, using brakes to control speed?
3. attempt to stop engine by turning key off?