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Author Topic: cold start questions  (Read 3259 times)
HighTechRedneck
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« Reply #15 on: January 15, 2007, 06:43:11 AM »

From what I have understood, fast idle is critical for extended idle to minimize deposit buildup in the cylinders.  It also keeps the oil pressure at a healthier level.  My engine manual advises against extended idle time, but like has been noted, every former commercial coach or transit has idled a lot in its life.
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Chaz
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« Reply #16 on: January 15, 2007, 06:44:55 AM »

On my 8V71, I have that little cup too. I tried spraying down it with a regular spray can but it didn't seem to work.
 Mine also has an ether start on it so I used the upside down big can in it's holder and ran a plastic airshock line over to the cup. It coils up so i don't leave it in the cup. But when I use it, I stretch the hose over and shove it down a couple inches and it does the trick.  But I would also suggest it as a last resort. My motor is tired so I have to use it more than I want to.

   Getting it started,
        Chaz
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« Reply #17 on: January 15, 2007, 06:54:16 AM »

Another vote for the block heater over letting it idle all night, is that i doubt i could sleep very well with the noise and worrying about exhaust,,, unless i was very tired, or the prior night's cocktail hour was a particularly good one! I run the genset each morning for a bit while making breakfast, so it is just an easy task to plug in the block heater when it is needed.
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« Reply #18 on: January 15, 2007, 08:26:46 AM »

Hello.

Let's remember Phil's original problem.

He has to go out in the cold to where he has no external support and he has not get his winter starting aids (block heater, etc) installed yet.

Yes, it is nice to have alternative methods to warm the ol' Detroit up before starting it, but what does a busnut in the earlier stages of the job, or one who finds himself with defective starting aids, or right now in the souther USA, with freak weather that the intended use of the coach was not designed for?

Phil, you can wedge the throttle open just a bit either at the pedal or in the linkage at the rear to bring the revs up a few, if you would like to, when the fast idle is not functioning.

One of the big issues for fast idle has more to do with temperature, and the production of electricyt for the big blowers. On base idle, the coach heating will suck the heat right out of the motor, and run the batteries down. Leaving it running below 150 degrees or worse, in the sub-arctic, and the batteries weakened. High idle helps compensate for all the things we could list would be bad about running at low temps.

When I did not have other methods of staying warm, I found good results with my 8V71 running on base idle, with the Webasto engaged, overnight,  Parked slightly nose down, (gravity heating? Grin) defroster on, sleeping in rear under all the blankets. In the AM, temp gauge read operating temp of 180, the interior was cool, but that was what I was after rather than listen to the big coach fans and the high idle and quite to my surprise, little smoke on pulling back onto the highway.

Back in those years, the truckers were just idling theirs and pulling up the covers.

happy coaching!
buswarrior

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DrivingMissLazy
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« Reply #19 on: January 15, 2007, 09:23:03 AM »

I am of the opinion that the harm caused by occasional overnight idling is mostly an old wives tale that keeps being repeated by those who have heard it. I have never seen anything in writing, by a knowledgeable source, which indicates that overnight idling really does that much harm. Especially only one night as Phil needs to do.

I know that I did it several times when I was having Webasto problems and was waiting on a repair part. Temperatures were in the low 20's at night and I set the high idle at about 1000 rpm. Still had to throw a blanket over the radiator to try and get the temperature up some. I really did not have any great amount of smoke in the morning either. For 50 years or more truckers have been idling their trucks overnight to keep warm and many of these truckers are Independent Owner Operators, not fleet drivers.
I would really like for some of these people crying wolf to come up with some certified data, or forget about it.
Richard
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« Reply #20 on: January 15, 2007, 09:50:25 AM »

I don't believe there's anyone in the trucking world or the large diesel business that doesn't know that idling a diesel engine for extended periods is detrimental to the engine (not to mention the environment) and there's more information about that just on the Internet than one person ought to have time to read (and even more in trucking-related periodicals).  It's not a matter of whether it's bad, it is; it's a matter of how bad.  It's a compromise and one I made for several years in my own truck (and I was an owner/operator); either idle the engine or die from exposure.  The engine lost.  The day I picked up my first brand-new truck the head mechanic came out to go over it, looked me straight in the eye and said "It's your truck, do what you want; just know every hour you idle this engine is the equivalent wear of running down the road two hours".

To this day I'd idle (on fast idle) my engine overnight if it meant being safe or comfortable (which includes being able to get the thing started in the morning) and not worry about it; I just wouldn't do it on a regular and on-going basis (to say nothing of the fact that the practice is becoming illegal in many areas).  There are lots of ways nowadays to not have to idle a diesel overnight that have not been readily available over the last several decades and many more OTR trucks are being equipped with APUs and such.  The Webasto exists because they figured out in Europe a long time ago that it was the best way to heat a truck and engine versus idling the main engine.  If you idle overnight you can just consider your engine for the moment to be the world's most expensive personal space heater.

You're not going to kill the enigne in one session or over many but just knowing there's a better way makes it hard to do on a forever basis.
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Les Lampman
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« Reply #21 on: January 15, 2007, 09:51:12 AM »

I am of the opinion that the harm caused by occasional overnight idling is mostly an old wives tale that keeps being repeated by those who have heard it. I have never seen anything in writing, by a knowledgeable source, which indicates that overnight idling really does that much harm. Especially only one night as Phil needs to do.

Busted Knuckle lost a 6V92 in his MCI after working a fairly long Katrina contract.  The bus was idled a lot to provide A/C there.  I don't how good the engine was before that, but I'm sure BK could fill in the details.

Brian Elfert
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« Reply #22 on: January 15, 2007, 09:55:23 AM »

My bus is still sitting at C&J Bus Repair because it is 10 degrees right now and I don't even want to try starting it without any preheating aid.  I'm also not picking it up because we just got 6 inches of snow overnight.  It should be in the 20s in a few days and I will pick it up then.

I should have had a block heater installed when the coolant was drained, but I didn't.  I expected to get my Proheat installed.  Best laid plans you know.

Brian Elfert
« Last Edit: January 15, 2007, 11:00:48 AM by belfert » Logged
HighTechRedneck
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« Reply #23 on: January 15, 2007, 10:09:42 AM »

I would really like for some of these people crying wolf to come up with some certified data, or forget about it.
Richard



I personally have idled all night to stay warm once and noticed no problem.  And like I said, all  former comercial coaches and transits have idled extensively already.  But I don't doubt for a minute that it can shorten engine life.  But here is some information from the manual and an article from Fleetmag.com citing a study:

Quote from: Page 68, RTS Coach Operating Manual (C-8724-A)
ENGINE IDLING
Avoid unnecessary or prolonged idling.  The engine cools faster when allowed to idle in extreme outside temperatures.  This can cause deposits to form in the comustion chamber, on exhaust valves, and around piston rings.

If you plan to park for more than a minute or two or to leave the coach shut off the engine.  If idling is absolutely necessary due to the nature or conditions of the run, try to maintain 1000 engine rpm (Fast Idle).



Article from Fleetmag.com - "Shutting Down", by Mark Gehred-O'Connell
http://fleetmag.com/articles/2004/fm0304/fm0304_02.htm

Quote
According to Natural Resources Canada (NRCan), when an engine idles for extended periods, engine oil becomes contaminated more quickly, because of the large amounts of intake air. At 600 rpm, excess air in the combustion cycle cools the cylinder liners, resulting in incomplete combustion and condensation of unburned fuel on cylinder walls. These deposits are drawn into the oil sump where they contaminate the engine oil and reduce its lubricity.

NRCan studies show that prolonged idling can reduce the operating life of diesel engine oil by 75 percent, from 600 engine-hours to 150. NRCan also finds that idling produces carbon deposits and unburned fuel residues that accumulate and can damage spark plugs, fuel injectors, valve seats and piston crowns.

Studies performed by Caterpillar, Inc. indicate that low engine operating temperatures at idle will allow water vapor to form and condense in the crankcase. The water in the crankcase will combine chemically with sulfur oxides and result in sulfuric acid. The acid can damage bearings, cylinders, piston rings and valve stems. According to the company, this damage could result in a 15 percent reduction in engine life.

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captain ron
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« Reply #24 on: January 15, 2007, 11:18:13 AM »

According to my DDEC my bus has idled more than it has been driven.
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buswarrior
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« Reply #25 on: January 15, 2007, 12:14:31 PM »

Good info, keep it coming!

Keeping it in perspective, running the engine to drive the coach is harmful to it, what with all that heat and wear and load....

I'd suggest that you will find written material from reputable sources that a minute of idling is equivalent to a minute of highway driving, so your mechanic wasn't far off, and he was trying to be helpful to a young business man!

Thanks Capt'n!!!

False prophets and lesser Gods will be exposed, the truth is out there!

happy coaching!
buswarrior
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DrivingMissLazy
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« Reply #26 on: January 15, 2007, 12:28:27 PM »

I am of the opinion that the harm caused by occasional overnight idling is mostly an old wives tale that keeps being repeated by those who have heard it. I have never seen anything in writing, by a knowledgeable source, which indicates that overnight idling really does that much harm. Especially only one night as Phil needs to do.

Busted Knuckle lost a 6V92 in his MCI after working a fairly long Katrina contract.  The bus was idled a lot to provide A/C there.  I don't how good the engine was before that, but I'm sure BK could fill in the details.

Brian Elfert

And I believe this is how a lot of the old wives tales got started. I agree that long term idling is not really good for the engine, or the environment, but I seriously doubt that a few weeks running at idle was the main cause for the engine failure.
At the radar stations I was once working at, we run the engine gen sets for literally days at a time with no load during bad weather. They were running at 1800 rpm instead of 1000, but I never ever heard of the failure of one because of this.
Richard
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« Reply #27 on: January 15, 2007, 12:52:00 PM »

I would really like for some of these people crying wolf to come up with some certified data, or forget about it.
Richard



I personally have idled all night to stay warm once and noticed no problem.  And like I said, all  former comercial coaches and transits have idled extensively already.  But I don't doubt for a minute that it can shorten engine life.  But here is some information from the manual and an article from Fleetmag.com citing a study:

Quote from: Page 68, RTS Coach Operating Manual (C-8724-A)
ENGINE IDLING
Avoid unnecessary or prolonged idling.  The engine cools faster when allowed to idle in extreme outside temperatures.  This can cause deposits to form in the comustion chamber, on exhaust valves, and around piston rings.

If you plan to park for more than a minute or two or to leave the coach shut off the engine.  If idling is absolutely necessary due to the nature or conditions of the run, try to maintain 1000 engine rpm (Fast Idle).



Article from Fleetmag.com - "Shutting Down", by Mark Gehred-O'Connell
http://http://fleetmag.com/articles/2004/fm0304/fm0304_02.htm

Quote
According to Natural Resources Canada (NRCan), when an engine idles for extended periods, engine oil becomes contaminated more quickly, because of the large amounts of intake air. At 600 rpm, excess air in the combustion cycle cools the cylinder liners, resulting in incomplete combustion and condensation of unburned fuel on cylinder walls. These deposits are drawn into the oil sump where they contaminate the engine oil and reduce its lubricity.

NRCan studies show that prolonged idling can reduce the operating life of diesel engine oil by 75 percent, from 600 engine-hours to 150 .
NRCan also finds that idling produces carbon deposits and unburned fuel residues that accumulate and can damage spark plugs,   fuel injectors, valve seats and piston crowns.

Studies performed by Caterpillar, Inc. indicate that low engine operating temperatures at idle will allow water vapor to form and condense in the crankcase. The water in the crankcase will combine chemically with sulfur oxides and result in sulfuric acid. The acid can damage bearings, cylinders, piston rings and valve stems. According to the company, this damage could result in a 15 percent reduction in engine life.



You know, I am truly inclined to trust the studies performed by anyone that is concerned about spark plug life in a diesel engine.   

And by my calculations 600 engine hours is equal to about 36,000 miles at 60 mph. Reduced by 75% that would be about 9,000 miles.
Who is this outfit anyhow?
Richard
« Last Edit: January 15, 2007, 01:03:05 PM by DrivingMissLazy » Logged

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride
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« Reply #28 on: January 15, 2007, 01:03:40 PM »

I, along with everyone else, will agree that the block heater is the optimal solution. However, because of the way the original question was stated, we'll skip past that as an available alternative.  I also won't enter the extended idle or ether debates.  Instead I'll throw out another alternative as proposed at   http://www.tejascoach.com/tejasoil.html#Cold

Take a suitable container such as one of those metal oil change pans.  Fill it with charcoal and light it.    Wait for the flames to die out.  Then slide it under the engine block.  Exercise caution to make sure flammable materials are kept far enough away (of course).

I've personally have never tried this, but I would think this should boost temperatures enough to make the start easier.

WEC4104
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« Reply #29 on: January 15, 2007, 01:13:00 PM »

Natural Resources Canada is a department of the Canadian Federal Goverment.

The quote referred to "when an engine idles for an extended period of time"  apparently is valid on both gasoline and diesel engines in regard to the components that it refers to.

Richard: Here is a link to one of their pages where they have a link to "ask the experts"  so you may want to ask them questions about the study.

http://www.nrcan-rncan.gc.ca/inter/products_e.html
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