Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > The Bosun's Locker > Engines | Propulsion | Generators
Cruiser Wiki Click Here to Login

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-19-2007, 06:22 PM   #1
Ensign
 
manor's Avatar
 
Join Date: Feb 2007
Posts: 38
Thumbs up

Some years ago in our marina a new motor cruiser was running his engine at the dock. Low and behold - RUNAWAY. After lots of running around & shouting on the dock and no-one knowing what to do it suddenly stopped (after what seemed like a very long time). The result - lots of oil and engine block pieces strewn all over the engine room.

Fortunately, this is not a common occurence but it certainly can happen.

Has anyone here had this happen to them? And, how did you stop the engine? What did you learn from the experience?

Some research on this rather frightening experience:

From a Mercedes website:

General causes of a run away diesel:

If the turbo seal leaks on the intake side, it feeds unregulated fuel into the combustion chamber.

If the piston rings leak on the compression stroke, the crank case oil mist gets blown through the CCV (crank case vent) and into the intake, this feeds unregulated fuel into the combustion chamber, add a restricted or dirty air filter and you have a run away diesel.

An over full crankcase oil level can cause massive unregulated fuel into the combustion chamber leading to a run away diesel.

If the intake valve guides leak and the head oil drains are clogged with sludge, it feeds increasing amounts of unregulated fuel into the combustion chamber, which can cause or contribute to a run away.

If the piston rings leak on the intake stroke, it feeds unregulated fuel into the combustion chamber.

The larger the volume of unregulated fuel going into the combustion chamber, the greater the risk of a run away diesel.

Your best defense against a runaway is:

A clean intake system and air filter.

Regular oil changes.

Keeping a log of oil consumption.

Watching for excess smoke in the exhaust.

How can you stop a run away diesel?

There are three ways I know of to shut down a run away diesel:

Seal the air intake and starve it, this can be impossible if the duct work is on the intake.

Shove a 20 pound HALON or CO2 fire extinguisher in the intake and empty it.

Run for your life and come back when it has stopped naturally.

CAUTION: THE DECOMPRESSION LEVER MUST NOT BE USED TO STOP THE ENGINE EXCEPT IN EMERGENCY SITUATIONS SUCH AS RUNAWAY ENGINE OR THROTTLE DAMAGE, AS SERIOUS DAMAGE CAN BE DONE TO THE EXHAUST VALVES.

************************************************** ******


Shutting off the fuel supply will not necessarily stop the "runaway" as it could still run on the oil at extremely high temperature.

And, from a Yanmar website:

"Hydrocarbon vapors in the intake air will sustain a runaway even with the primary fuel source removed. A diesel engine will burn a very wide variety of fuel, especially when at operating temperature, fuel is fuel, if it burns the engine will run, crank case oil will burn as fuel."

PLEASE share any knowledge of this possible problem.

__________________

__________________
manor is offline   Reply With Quote
Old 07-19-2007, 06:36 PM   #2
Admiral
 
Trim50's Avatar
 
Join Date: Feb 2006
Home Port: Who cares really...
Vessel Name: T
Posts: 1,215
Send a message via Yahoo to Trim50
Default

Shut-off the fuel supply and slowly pour a cup of water into the air intake. It will turn to steam as it hits the intake manifold then cool the intake gasses. If you do it too fast, you'll get hydro lock, and that will surely stop the engine. I certainly don't recommend this method, but it could work in a pinch.

The CO2 fire extinguisher is probably the best idea.
__________________

__________________
[
Trim50 is offline   Reply With Quote
Old 07-19-2007, 07:11 PM   #3
Rear Admiral
 
Join Date: Feb 2006
Posts: 437
Default

Slip a piece of plywood over the intake - combustion requires air.

Never attempt to use your hand!

Kirk
__________________
Gallivanters is offline   Reply With Quote
Old 07-19-2007, 07:39 PM   #4
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

Quote:
Originally Posted by Gallivanters View Post
Slip a piece of plywood over the intake - combustion requires air.
Or maybe keep a tennis ball in the engine room and hope like hell that access to the air intake is easy when the engine is "screaming".

Phew!
__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 07-19-2007, 08:56 PM   #5
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

Found this:

"Diesel engines will runaway uncontrollably if there is a lubricant or fuel leak into the intake tract. Broken piston rings or failed turbocharger seals can cause a diesel to run at almost full power with no input from the operator."
__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 07-20-2007, 01:29 AM   #6
Commander
 
Join Date: May 2005
Posts: 143
Default

According to Michael, the mechanical engineer:

If you can safely put the engine into gear, thus loading it, the rpm will remain in a much safer range. I had one experience in the Navy on a crash boat where one of the twin Detroit diesels ran away. We slapped it into gear and turned off the fuel supply, which stopped the engine after about 90 seconds. Meanwhile the boat was heading up a narrow waterway with the starboard engine making the boat hard to maneuver. No damage was done to the engine and we found out that the injector pump governor had caused the problem.

In theory, pouring in water will work, but due to the emotional overload of the moment, guessing the proper amount for safe shutdown would be hard to manage. You don't have a lot of trial-and-error time before the engine will be seriously damaged or self-destruct, so the CO2 fire extinguisher discharged directly into the air intake will choke off the combustion air and kill the engine without causing any damage.
__________________
SeaVenture is offline   Reply With Quote
Old 07-20-2007, 04:00 AM   #7
Admiral
 
Auzzee's Avatar
 
Join Date: Jan 2005
Home Port: Darwin
Vessel Name: Sandettie
Posts: 1,917
Default

I am always thankful for the good things I learn here. I am going to buy a CO2 extinguisher which I can mount close to the air intake on the GM353.

Thanks

David.
__________________
"if at first you don't succeed....Redefine success"!


Auzzee is offline   Reply With Quote
Old 07-20-2007, 05:48 AM   #8
Ensign
 
Join Date: Jun 2007
Posts: 4
Default

This is exactly why I love reading these boards!

Runaway Diesels!!!!! Who knew?!?!

Now however, I know... and more importantly, I now know what to do about it!

Thanks!
__________________

__________________
CapHillHandyman is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wanted 20-30 HP Reliable Diesel Engine woodymr Cruiser's Market 0 07-30-2010 04:27 PM
1972 Volvo Md 2b Diesel Engine Aquaria Cruiser's Market 3 05-26-2010 06:29 PM
Diesel Engine's Exhaust Colour manor Engines | Propulsion | Generators 0 07-19-2008 06:52 PM
jabsco diesel engine waterpump hangfire General Cruising Forum 1 05-17-2006 05:33 PM
Diesel engine Auzzee Engines | Propulsion | Generators 3 02-08-2006 01:49 PM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 12:33 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0
×