2nd Gen Non-Engine/Transmission idleing for prolonged time

[rrab1]

idleing

When they talk about prolonged idleing arethey talking about 800rpm when at work I idle mine up to 1100rpm and so for everything is o. k. There are time's when it run's for 45min.

 

[redram]

You know I just don't care what Dodge has to say on the subject. I have always just let it idle when needed and have never had any problems. I do not let it idle over night or anything, but I have gone as long as 2-3 hours. I have never gotten any diesel fuel in the oil, nor have I had any adverse reactions to the extended idling.

How do you know you haven't gotten fuel into the oil? Do you perform routine oil analysis at every oil change?

Diesel fuel and engine oil are both hydrocarbon based so they mix readily in the crankcase. If it gets so bad that you can detect it visually on the dipstick, it will mean there is about 5-6% fuel contamination. Bearing lubrication degrades at anything over 1-2% fuel contamination - which would take a very experienced oil anlysis lab tech to detect unless performing viscosity checks, flash point checks or an FTIR on the used oil.



You're right, it's your choice and you're probably right, you're not going to have your engien fall apart but for the $20 it takes to install a manual throttle lock, why would you want to take the risk on a 7500 motor?

And you're right, it's your choice and most of us here really could care less if you idle your engine for extended periods.

Cheers and happy holidays.

 

[redram]

has anyone on this 20k member site lost an engine due to extended idling?



i've never heard of one yet ...

Previous post by another member had to perform internal engien repairs attributed to excessive idling... ... .



It's your choice. :-laf

 

[MVieira]

Working for a CAT dealer I've got a lot of customers who idle their machines for long periods, they are usually plants or pits with wheel loaders that run 24 hrs. a day. They look at it as the lesser of 2 evils. It is better than starting and stopping constantly and also they don't run the risk of 4 corner seizure on the pistons from an operator not letting it warm up and putting them under heavy loads too quick. BUT!! when their engines are at the end of their lives the extended idling takes its toll. When we tear their engines down for rebuilds we usually see; heavily varnished and stuck oil rings, heavy varnish on the valve stems, tons of carbon build up in the combustion chambers and valve heads, and caked or carbon build up on the injector nozzle orfaces. Some even start slobbering oil out the exhaust at idle by the time they are due for rebuild. You take the same model machine that is worked hard all day and not idled alot and you don't see those problems. Just my $. 02 worth. Mike

 

[OTRPU]

When we're out on the road we live in our trucks. In the Summer you need A/C and in the Winter you need the heater. Know a few haulers with greater than half mil on their trucks. Some have problems, but none has ever mentioned the problem was or caused by extended idling. All kinds of things fail and fall off, lots of fall offs are caused by extended idle time. Vibration just works things loose and bolts back out. I personally haven't had alot shake off my Ram, but the power steering pump mounting bolts backed out on my PSD. Belt tension cocked the unit, ended up snaping the pulley off. On the road of course. My preference is to get alternate heating and cooling systems installed, and run them from seperate deep cycle batteries. In a perfect world that is.



Cheers,

Steve J

 

[HBarlow]

Mike:



Thanks for an excellent and informative post on the subject of extended idling. Yours is the first post I've ever read that actually described the result of extended idle time from a mechanic's point of view. As I understand the situation, we can get by with it for years but it will shorten engine life and when the engine is worn out, the damage is significant.



Harvey

 

[av8r]

I am not a mechanic nor do I play one on TV.



In my layman's logic, doesn't idling a piece of heavy equipment (tractor, loader, etc. ) which uses a direct drive hydraulic system puts enough load on the motor to build some engine temp (and hydraulic oil temp) at low outside temps? Unlike my CTD where spinning only the flywheel uses virtually no power (fuel), hence the need for the $20 throttle cable.



Also, isn't this just a cold weather thing? How would low idling to run the a/c in the warm weather cause a problem?

 

[JerryTurbo]

My Oh My

Summer or winter 8hrs of idling is necessary for comfort and making sleep a reality.

Its good that my odometer doesn't run when idling.

 

[MVieira]

av8r, Yes the hyd. pumps are driven directly off of the engine's accessory drive. Most of the new CAT machines use a closed center load sensing hyd. system with a variable displacement piston pump. When there are no hydrualic functions in use, the pump is destroked and very little load, if any, is noticed at idle, until you pull an implement lever and then the pump is signaled to stroke up to meet demand. The older CAT machines used an open center system with a fixed displacement gear or vane pump, where oil constantly flows freely through the center of the valve and when you pull a lever the valve spool now directs the oil to work cylinders and a load is put against the pump and the engine. Point being if you are not using any of the hydraulic implements on the machine, there is very little load on the engine and not enough to warm it up. The movement of the hyd. oil causes some heat in the hyd. system, enough to keep it warm in cold weather. I'm not an expert in cold weather, I just know what I've seen when we rebuild engines that idled alot and are not worked hard. I've been taught on heavy equipment that they should be idled for 5 to 10 minutes after start-up in the morning, then gradually put loads on the machine until the engine/trans/hyd temps are up to operating range and then the machine can be operated at full load, then at quiting time you should let it idle for 5 to 10 minutes before shut down to cool the turbo and other systems. I care about my truck and I try to apply these same principles so it will live a long & happy life. I don't think extended idling will cause an immediate failure but I wouldn't let my truck idle for more than 10 to 15 minutes without kicking the idle up to at least 1200 RPM.

Mike

 

[HBarlow]

av8r:



I'm not a mechanic or tv pretender either. It is hard to argue with the experience of the transporters and hotshotters like JerryTurbo above. Those guys prove how tough our engines really are.



I only know what my EGT gauge tells me. If I let my truck idle using the Practical Solutions Fast-Idle kit to hold rpm at 1000 or 1200 in cold weather, temps remain well below 300° shut down temp. In the summer, with ac on, temp will remain slightly above, maybe 350°. On the other hand, if I engage the Jacobs exhaust brake, EGT increases to a little above 400° and remains there.



I'll never put as many miles on my truck as the transporters and hotshot haulers do so it probably doesn't matter but I feel pretty safe using the exhaust brake for stopping, for faster warmups, and for maintaining engine operating temperature during periods of idle like rest room breaks. I've never had any reason to idle mine overnight but I think the exhaust brake would prevent varnish and carbon build up even under those conditions. I consider an exhaust brake essential equipment for commercial hauling.



Harvey

 

[noland]

Mine idles 20 hours or more per week and shows no signs of trouble yet at 299K miles.

I'm sure that Cummins knows what they are talking about and that prolonged idling should be avoided, but I have not had any problems... so far anyway.

 

[RustyJC]

HERE'S the Cummins bulletin.



Rusty

 

[2broke2smoke]

excellent tsb



though it is referring to "arctic temperatures"



no where in there does it say not to do it ...



though it does say that after 6 hours of idle you should warm up the motor to operating temps to burn up any possible carbon deposits ...



and i think that is exactly what most people do ...



i haven't heard anyone say " i wanna idle in the cold for 6 hours and shut it off cold"



oh ... i still would like to hear from someone who had a bent pushrod



so we could see just exactly what sort of extended idle they did to cause problems

 

[HBarlow]

Rusty:



Interesting info provided by Cummins. I'm frequently impressed and grateful to learn that Cummins has provided guidance on many of the issues we wonder about.



The writer was referring to arctic conditions but the advice probably applies to all cold weather idling. The article did not address summer temperatures and idling with the ac compressor cycling so possibly that is not a concern.



I always use my exhaust brake when idling more than a couple of minutes and have never idled the engine for longer than 30 minutes so I'm hopeful I'm not building up varnish and carbon.



Harvey

 

[RustyJC]

Harvey,



To the dismay of some of my RVing neighbors, I'll start the truck and let it idle against the exhaust brake to warm up while I'm hitching up the 5th wheel. I just try not to do it before 6:00 AM! #@$%! #@$%! :-laf



Rusty

 

[GKinney]

idle temp

The reason that DC and Cummins suggests not to idle for long periods of time... . isnt the time itself... but the engine temp. It states in the owners manual and my Dodge shop manual that you are not to idle longer than 10 minutes below 140* water temp. The fuel will not completely burn at or below 140*... hence if you can idle it up or keep the water temp above 140* you are a lot better off. Just made an appointment today to have my ecm re-flashed and have the 3cyl. high idle feature enabled on Fri. It is only going to be a high of 14*... so guess I can test it out. Keep 'em warm.

 

[cmills]

12 valve

So does this mean if you have a 12 valve you can just let it idle and not worry about it?

 

[GKinney]

12 valve

cmills... . no all my 12 valver manuals say the same thing... . or any diesel for that matter. When the fuel is not burned completely... it gums up the valve stems and guides..... and in some cases causes them to bend. Never heard of any cases like that... . but makes you wonder I guess. I installed a hand throttle kit on my '89 auto that I bought from Dodge. Luckily the parts man was courious as to how it would work... . so he sold me all the parts for cost... so that saved me about 200% mark up. Worked great. Wish they had the same set up for the 24 valvers.

 

[PCarbonaro]

av8r:





I only know what my EGT gauge tells me. If I let my truck idle using the Practical Solutions Fast-Idle kit to hold rpm at 1000 or 1200 in cold weather, temps remain well below 300° shut down temp. In the summer, with ac on, temp will remain slightly above, maybe 350°. On the other hand, if I engage the Jacobs exhaust brake, EGT increases to a little above 400° and remains there.



I've never had any reason to idle mine overnight but I think the exhaust brake would prevent varnish and carbon build up even under those conditions. I consider an exhaust brake essential equipment for commercial hauling.



Harvey

Harvey, I'd like to think the exhaust brake is enough, but others say that the exhaust brake is not enough to get the engine warm. EGTs are one thing. I'd go by engine (water) temp, but is that gauge really accurate? (In my race car, I do have an electronic water temp. gauge that I do trust). A previous post says that 140 degrees is the magic number...

 

[GSnook]

I have found that when idleing in cold temps leave the cab control on recerculation and the engin warms right up to operating temp no matter how cold it is out side the cab

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96 automatic 4/4 Banks stuff 430,000 lots of tires and brakes