Run away diesel, why does it happen? - Page 9 - PeachParts Mercedes-Benz Forum

#**121** 03-19-2007, 02:05 AM

You sure have alot of new customers all of a sudden.

truckinik · #**122** 03-19-2007, 02:57 AM

Quote:

Originally Posted by Hatterasguy

I saw an engine run away in a 63ft Ocean sportfish. I think it was a 12V92TI or it might have been a 16V92TI. The owner was coming into the harbor at wot, when he went to pull back the throttles the port engine would not come down. Now keep in mind he was a novice boater who had just bought the boat, and he was heading into a crowded harbor at 30+ knots, he was about 1 1/2 miles off the at the time. He also tried the emergency shut off's but they didn't work for some reason. Well insted of turning the boat around and heading back out to figure out the problem. He decides to take it out of gear!!!

Now we are talking about a diesel running at 110%, now with no load, my god that thing smoked and made noises diesels shouldn't make! Black smoke was pouring out of the exhuast, the boat looked like it was on fire! I was about 1/2 a mile off it at the time. It seemed like a long time but probably no more than a minute the engine self destructed and went silent. The police etc came out but the Ocean did go in under it's own power. My dads friend is a diesel mechanic, he had just finished majors on this boat the month before. He was called back and basically came to the conclusion the engine was shot, it sucked the turbo in! Rods and valve peices were everywhere he said. What a mess, but nothing $100k couldn't fix. I don't remember what failed a fuel valve of some sort. In hindsight the boat only had a couple hundred gallons of fuel on board he should have pulled the starboard engine back and let the port suck the fuel dry.

That sounds like a pretty scary situation to be in. On a boat, off shore, with a runaway... I don't know if I would abandon ship, or stick around. If the engine had grenaded, it could have been a lot worse. Granted, it sorta did, but WOW that is just a crazy situation to be in. One of my 79 300CD's takes about 5 to 6 seconds after you turn off the key, to finally shut down. Anyone have any ideas? I'd like to solve the problem. She's been sitting a long time, and I just got her going a few days ago. Today, I changed out the fuel filters, and I think I bled the system completely, but can't be sure. I put in a strange mix of Diesel fuel, and additives also. I did this to try and clean up the half-tank of 4 and a half year old Diesel fuel in the car. I also did new glow plugs, and changing the oil tomorrow morning for the first time since before the car sat. Changing all of the rest of the fluids as well. Fuel will just be burned off though. Not trying to remove the tank. Not as easy as Chevy p.o.s. to drop a tank. Isn't it behind the seat in back sitting up-right? Sounds like a lot of work to me. I could just drive the fuel off, a whole lot easier, and faster, too.

#**123** 03-19-2007, 03:21 AM

Quote:

Originally Posted by truckinik

One of my 79 300CD's takes about 5 to 6 seconds after you turn off the key, to finally shut down. Anyone have any ideas?

Weak vacuum supply or a leak going to (or in) the shutoff diaphragm.

truckinik · #**124** 03-19-2007, 03:40 AM

Quote:

Originally Posted by ForcedInduction

Weak vacuum supply or a leak going to (or in) the shutoff diaphragm.

Ok, I'll check all that first in the morning. Thanks a lot.

Diesel240D · #**125** 08-14-2007, 01:24 PM

My 1975 240D doesn't have a fuel shutoff value, what can I do to prevent a runaway engine on my car ?

Matt L · #**126** 08-14-2007, 02:31 PM

Quote:

Originally Posted by Diesel240D

My 1975 240D doesn't have a fuel shutoff value, what can I do to prevent a runaway engine on my car ?

The same thing that you would do if you had such a valve. A fuel shutoff valve is useless against a runaway engine.

Diesel240D · #**127** 08-14-2007, 04:26 PM

Quote:

Originally Posted by Matt L

The same thing that you would do if you had such a valve. A fuel shutoff valve is useless against a runaway engine.

I thought I was a pretty good barn yard mech until this runaway diesel business, it's scary.

Thanks

P.E.Haiges · #**128** 08-14-2007, 06:54 PM

Diesel240D.

U have to cut off the oxygen supply. This can be done by blocking the air inlet or spraying a co2 fire extinguisher in the air inlet.

Shutting off the fuel doesn't always work because the engine can be running on lubricating oil sucked from inside the engine.

P E H

#**129** 08-14-2007, 10:01 PM

The 1975 240D has a shut-off butterfly valve in the governor throttle of the intake inlet.

P.E.Haiges · #**130** 08-15-2007, 02:03 AM

Forced,

Is that possibly a butterrfly valve to prevent the engine running in backward?

My old '59 180D had such a valve to prevent running backward.

P E H

#**131** 08-15-2007, 02:06 AM

The OM616 cannot run backwards as the cam is chain driven, the slack would cause the valves to hit the pistons. Your 180D had a gear driven cam (Something I honestly wish MB would have kept in their design).

Gurkha · #**132** 08-15-2007, 02:24 AM

Gear driven cams are indeed the best, just add to the cost slightly but in long run, definitely the best solution, my HINO engine has gear driven cam which has proved to be very reliable.

whunter · #**133** 01-15-2008, 05:30 PM

need to be made aware of this issue...

Please read the entire thread for full understanding of the issue.

BluEyes · #**134** 01-15-2008, 06:43 PM

Quote:

Originally Posted by ForcedInduction

The OM616 cannot run backwards as the cam is chain driven, the slack would cause the valves to hit the pistons. Your 180D had a gear driven cam (Something I honestly wish MB would have kept in their design).

My OM615 has a chain-driven cam and MB engineers decided to equip it with a anti-backrunning valve. I suspect at low engine speeds and for short periods, the chain tensioner would be strong enough to keep the cam in roughly the right place. There is only a few degrees of slack in the chain after all. With the oil pump moving oil the wrong way, the bearings would probably die before the tensioner wears out and the valves hit the pistons.

Gurkha: was the HINO OHC, or cam-in-block? Never heard of a gear driven OHC before, only shaft driven...

nomorehurry · #**135** 01-30-2008, 12:14 AM

I have a similar problem on an 82 300D turbo, (182 K miles - owned 2 months & driven almost daily) the engine occaionally starts to accelerate from an idle with no pressure on the pedal. The engine will stop if the key is turned off, so I am assuming it is not caused by chankcase oil burning in the pistons. I do have an EGR from the top of the head cover into the air intake. Am I experiencing the beginning of a run-away problem? If so, what is the likely cause and how do I make it go away?

I do not have a CO2 extinguisher, but will have one very soon. If I do get a run-away, can I stick the nozzle of the CO2 extinguisher in the air intake to the air filter and squeeze the trigger or do I have to force the CO2 down the turbo? I am not familiar with diesels, but I am learning! (mostly from this site). I would appreciate a direct reply and/or addition to this thread.