Run away diesel, why does it happen? - Page 5 - PeachParts Mercedes-Benz Forum

Matt L · #1 03-07-2007, 01:16 AM

Quote:

Originally Posted by Gordo

Has anyone heard of, or had experience with, runaway from using VO or other alternative fuels. I know it is popular practice to change pluming around so the primer pump is between the spin-on filter and the IP. Could this mod cause a problem?

This is unrelated. A diesel can run away simply because it uses a lubricant which is capable of running the engine. The normal fuel source is not an issue at all.

vstech · #2 03-07-2007, 01:47 PM

well, the normal fuel source CAN be an issue if something mechanical is amiss. re read some of the earlier pages and you will see that you can get a runaway with stop lever modifications, or improper linkage problems etc...
John

Matt L · #3 03-07-2007, 02:06 PM

Quote:

Originally Posted by vstech

well, the normal fuel source CAN be an issue if something mechanical is amiss. re read some of the earlier pages and you will see that you can get a runaway with stop lever modifications, or improper linkage problems etc...
John

I disagree. Continuing to run because the shutoff circuit has failed is not run-away.

The IP can only deliver a fixed maximum quantity of fuel per stroke, even if the governor failed. If the governor is intact, no linkage problem can even approach a runaway condition. If the governor has failed, you'll get higher operation, but still not as bad as you can get from lubricating oil which is nearly unlimited.

Runaway happens when the oil consumption is a function of engine RPM.

vstech · #4 03-07-2007, 02:22 PM

that makes sense.
but in a garage a vehicle that is operating at WOT with no way to shut it off due to mechanical malfunction is certainly a run away.
perhaps not as immediately disastrous as the oil ingestion, but still very dangerous.
were this to happen on the highway, it could definitely be bad.
John

#5 03-19-2007, 02:05 AM

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

Diesel240D · #6 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 · #7 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 · #8 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

whunter · #9 07-13-2008, 01:02 AM

HELP 300 SD - Runaway Engine!
http://www.peachparts.com/shopforum/diesel-discussion/74316-help-300-sd-runaway-engine-post466575.html

whunter · #10 01-25-2009, 01:31 AM

Three run away diesel wrecked engine phone calls since the new year, and it is only 1-25-2009...

This is a very real issue, that can destroy the engine quick...

whunter · #11 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.

P.E.Haiges · #12 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

#13 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).

BluEyes · #14 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...

Gurkha · #15 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.