I would like to know if anyone out there has had problems relating to or caused by extensive idling at normal idling rpms such as 600 -700 rpms. Thanks in advance for your input. bc

I idle a lot,it's just the nature of my business 42,000 miles 2000 hours. Dealer says could cause premature flywheel problems on ZF6. I don't think it has caused any problems, that I can think of anyways. Why do you ask?

The Cummins 505 service manual for one of the machines where I work states the following about extended idle times.

"extended idle time can cause cylinder wash, when the cylinder temperature drops not all of the fuel is burned in the cylinder causing the unburned fuel to wash the oil off of the cylinder walls causing excessive ring wear." "unburned fuel can cause injector tip clogging."

Now this engine is about 15 years old, so its older technology. The injectors on the Dmax are more advanced and spray a precise amount of fuel just to keep the engine running at an idle. But can "cylinder wash" happen in the Dmax, I don't see why not. I would think cold weather idling would be the hardest on it. I personaly let my truck run at a high idle for long periods of time, but try not to idle at 600rpms for more than 30-45mins.

The Cummins 505 service manual for one of the machines where I work states the following about extended idle times.

"extended idle time can cause cylinder wash, when the cylinder temperature drops not all of the fuel is burned in the cylinder causing the unburned fuel to wash the oil off of the cylinder walls causing excessive ring wear." "unburned fuel can cause injector tip clogging."

Now this engine is about 15 years old, so its older technology. The injectors on the Dmax are more advanced and spray a precise amount of fuel just to keep the engine running at an idle. But can "cylinder wash" happen in the Dmax, I don't see why not. I would think cold weather idling would be the hardest on it. I personaly let my truck run at a high idle for long periods of time, but try not to idle at 600rpms for more than 30-45mins. It may be older technology but it's still true even for todays diesel engines.
I try not to let mine idle for more then 10-15 min and that is probably too long already. I know it blows some light blue-gray smoke as in to cold to burn fuel after setting and idling.
Just look at otr rigs. All new ones have an automatic high idle. After they idle at low RPM a set time then they kick up to high idle automaticly.



I don't see how idling will cause premature flywheel problems though. Anyone care to explain?

http://photos.imageevent.com/texasdutchman/challengermt745demo/websize/DCP01500.JPG

Brand new kitty Cat on the farm.

The best I could figure out about the flywheel problem is. Maybe the dampening from the dual mass with out load is causing the two pieces to become loose and noisey prematurely. Don't really know too much as I have never seen one apart just repeating what dealer had to say. Maybe someone who has worked on them might have a better opinion or answer. By the way mine goes in Monday for the third latest and the greatest flywheel. The first lasted 2 years second lasted 6 months.

Dutch, I agree with you 110%. Love the CAT. I'm a heavy equipment operator and get to run the BIG CATS, can't beat 'em.

That sure is a nice lookin cat. What size is it?

We do oil analysis on all of our equipment and it shows you should not leave diesels idling for long times. I do not recall why it was so bad, but our mechanic knows I'll try to ask. Is that true with your Dmax I do not know. However, growing up and before my time our farm equipment some of it might idle all day all of those tractors still run to this day. Cat makes some good stuff but are far from the best, that is a nice looking machine wish we had some that nice grown up.

We do oil analysis on all of our equipment and it shows you should not leave diesels idling for long times. I do not recall why it was so bad, but our mechanic knows I'll try to ask. Is that true with your Dmax I do not know. However, growing up and before my time our farm equipment some of it might idle all day all of those tractors still run to this day. Cat makes some good stuff but are far from the best, that is a nice looking machine wish we had some that nice grown up.
Who is the best then?:confused:

The issue described above is also called wet stacking. At work, we operate and maintain 25 diesel stand by generator sets, and this does happen. Our generators run pump stations, in which the pumps cycle somewhat infrequently. But the generators are sized to handle the max load the station could call for. So very rarely are the generators ever put to max load, and if so, for a very short period of time. RPM's really have nothing to do with it, it's all about loadand the heat load generates. So as part of routine maintenance, every year or two, we load bank each generator for a 4-6 hours. Load banks draw current from the generator and dissipate it as heat, just a big resistor. So you dial up roughly the max amps of the gen set and let her rip. It is amazing how much cleaner, quiet, and smooth they run after the load bank run. Our local air inspector also may require us to do it, if he is unhappy with the emmision clarity of the generator. Here is an article alking about this.

http://www.avtron.com/pdf/wp-WetStacking.PDF

As it relates to a DMAX, those who tow even a few times a year help this condition. Those who tow infrequently and live in cold climates should avoid idling log periods and use winter fronts as much as possible. But as it has been said before, the control of our injections systems is so much more advanced than older mechanical systems, that it is probaly less of an issue. Just something else to think about...

Who is the best then?:confused:
It's Green and Yellow.......:ro)

To bad they had to steal the track idea from Cat. As for me I am a red man:ro)

I think Red looks good on Chevys.......

I let mine run all night long on the average of 3 nights a week in the winter. One has 115,000 miles on it now. I have not seen anything to show that this is a problem.

Red is better than green):h

That is funny...):h ):h

how many deeres do you have

Two, a lawn mower and a snow blower. I don't have a farm, I'm a city boy. But, I have worked at Deere for 30 years in Waterloo Ia. If you like the red stuff that's o.k. with me. I'm just predjudice..........

Only have two deeres a lawn mower and 6410

I worked in the toolroom for 23 years. Jig bores, Boring mills, Jig grinders. Then they decerated it, started buying all their tooling from outside vendors. The love of my life was the Jig bore. I did get a job programing and running CMMs,(Ziess and DEAs) kinda like a Jig bore with out having to clean up chips.):h ):h
I'm retiring March 1st.:ro)

sounds like fun do you know if there are any engine plants in Wisconsin?

It's Green and Yellow.......:ro)
I hope you are talking about Deere ag. equipment only. From my experience the Deere heavy equipment is junk compared to CAT, Volvo, and Komatso.

That sure is a nice lookin cat. What size is it?


That is a MT 745 with the C-9 8.8l engine putting out 205 PTO hp or 255 gross engine hp.
Uses 13.5 gallons of fuel an hr at 100% load. May get a little better after it gets broke in good.
At 21 hrs on the clock it has already burned 2 gallons of oil.

Also have a new JD 8420 with 235 PTO hp. Has GPS with autosteer and ILS (independent front suspension) and an $1800 active seat.
It uses 14.5 gallons af fuel an hour at 95-100% load.

http://photos.imageevent.com/texasdutchman/challengermt745demo/websize/DCP01514_1.JPG

http://photos.imageevent.com/texasdutchman/challengermt745demo/websize/DCP01516_1.JPG

Why is it junk? I myself am a IH man:ro)



I hope you are talking about Deere ag. equipment only. From my experience the Deere heavy equipment is junk compared to CAT, Volvo, and Komatso.

how about JBC? they any good?

Well I like Deere that's mostly that we have on the farm but I'm not a farmer. Now for heavy equipment then we need look at after the sale service as well as quality and how well they do there job. My .02 is

excavator- Deere, Link Belt, and Komatso. Cats hydraulics are to slow

dozers-Cat only for there hi track design that aside Komatso and older Deere's

track loader-Deere except for the hydrostatic crap cant hear over that wine

motor grader- Cat is the only thing I have ran but heard good things about Komatso

wheel loader- Kawasaki turn on a dime and comfort

wheel dozer-Cat is again the only thing I have ran

scrappers- Well I wont go near them nor would I trust any scrapper hands opinion cause there only a little smarter than a truck driver and that's not a good thing (no flaming please I do have a class A):iamwithst

backhoe- Deere is the best

skip loader/box blade- Deere by far the best

This is only from my experience and the opinions of some of this industry’s other well respected operators sorry for this being off topic.

Volvo Wheelloaders are awesome:ro) , got one at our dairy, run it everyday. Over 14000 hours on it, never been rebuild, runs like a train!!!

Why is it junk? I myself am a IH man:ro)I'm non-union where I work so I get to wrench with our heavy equipment machanic on our stuff. When you tear into differant systems on our wheel loaders, track loaders, hoes, and dozers the design and quialty of the Deere vs. the Cat or Volvo don't compare. They don't seem to last as long either.

This is only from my experience with the equipment we have.

Our machanic worked for West Wide John Deere in Northern Illinois for 15yrs then has been on his own for the past 17. He says since being on his own and being able to work on all kinds of equipment. The Deere is not the worst but not to good when compared to Cat, Volvo, or Komatso. His has said the Case stuff isn't much better but talks highly of their skid loaders.

I let mine run all night long on the average of 3 nights a week in the winter.
why?

so idling is bad but is idling at higher rpm bad also since time to time I need to idle my track for 1-5hr at a time...what is reasonable idle on dmax thanks

We have ours setup with a "sleeper" in the back. When MT we are allowed to sleep in the truck and we use it for heat when needed.

I would say in the cold months idling for about 5 min would be ok, any more and your engine will start to cool down and you will get blow by/cylinder wash/etc...
Letting you truck run at higher rpms, say 1100-1300, will allow the engine to produce heat and help the rings to seal, preventing the blowby.
Long idling at low rpm could also be the reason for fuel in the oil, which has been seen in a few trucks. Carbon build up on valves, and the other problems stated earlier.

here is how i remember older fuel inj dosen't build up full pressure until off idle we used to bring up to 1000 rpm after oil pressure was up, injectors son't pop right at low pressure, most cat's don't have actual seal on air side, so intake will pull oil from turbo cartridge into airbox, raising rpm allows turbo to do its work and hold oil to its place.
duramax uses common rail fuel inj which is different from cat and detroit diesel it maintains minimum pressure to pop
properly so should not be big problem, but engine cooling down normally will generate washing cylinders leading to fuel oil dilution in oil. if you have to use high idle.
i have also noticed computerized vehicle gas and diesel
engines mileage is crappy seems from computer learning.

Maybe a tech can chime in here. I'm interested in getting a good time at which the Duramax can idle. For cold weather.....

I've been letting mine idle long enough for me to feel a little warmth coming out of the vents. Waiting for the needle to come off 160 takes about 15mins and I'm too impatient to wait that long (I can wait if I really should). Especially with all these threads saying that idling for too long is bad. As soon as I feel warmth I hit the road.. but baby it for the first couple of miles.

If someone has a better way please tell.. It takes me 20 minutes before I get off 160 degrees and I'm afraid to get on it..

I hope you are talking about Deere ag. equipment only. From my experience the Deere heavy equipment is junk compared to CAT, Volvo, and Komatso.(quoted by 454)


the only word that's right is CAT... and for volvo ,they only make a good semi tractor,and for Komatso they have not been in buisness longer than deere.just my two rusty cents.

Back to extended idling....
Engine oil temp is a key factor in determining how long or when to idle. If you can keep the oil temp up around 200 degrees Farenheit it will reduce(not eliminate) cyl. wash. It will also help keep the rings expanded out against the cyl walls, preventing excessive oil slobber and blowby.
I work on Cat engines all day everyday, and they just released a statement pertaining to their newest engines- If you're going to be sitting for more than 5 minutes, shut down the engine. With today's sophisticated electronics, the engine keeps track of idle time, amount of fuel used, etc. If you take a look at amount of idle time when you have an engine down for head gasket, rebuild or whatever, it shows a strong correlation between excessive idling and premature cyl wear, oil slobber, and gummy exh valves.
As for my Dmax, I idle as little as possible. If I'm sitting for 5 min. or so I usually shut it off. It will stay warmer when the engine is not running because the heat is held in the block and the coolant is not circulating. As many of you know, these trucks seem to have an oversized cooling system because they take a long time to warm up.
Just my experience, would like to hear other input as well.

thanks to all for the excellent technical information, after reading, i will consider the high idle option for future use in case i ever need it..its probably easier than trying to nap for a couple hours trying to hold the pedal down somewhat. ..awesome pix guys..the cat was cool, bob

so in my area that the engine temp gauge does not move more than 1/4 in city driving with front of my truck all covered even driving my truck allows cylinder wash as I read it correctly....

I talked to the dealer mechanic today. He said no problem. I don't know for sure, but I have not had any problems.

From the research I've done, "dead" idling any engine for extended periods of time is bad. High idling a diesel is generally considered to be acceptable but not necessarily "good" for an engine when it's not necessary, i.e. not cold weather, etc.

On the other hand, OTR trucks often idle for 6-8 hours a day, 6-7 days a week, year-round on petroleum oil and are expected to reach 1,000,000 + miles. Go figure!