Warm up and idling

[garth466]

A few things I'm wondering about with the snow falling. Proper starting and warm up for one and the other is let it idle or turn it off? If I am just stepping off I'll let it idle but if I am hopping off to use the chain saw or do something that may take 3-5 minutes I turn it off.

Is it better to shut her down for such tasks or let her idle. I know I would just be burning fuel, but is there more wear be the on and off?

I have a 3120 with edydro and she doesn't ever have a problem starting now that I have figured out that you have to push the key down for the glow plugs. I was just waiting for all the lights to go off like my truck. Always started, but not without turning over a few times and make a lot of initial smoke.

 

[Farmwithjunk]

Everyone has their ideas and theories on this issue. All I have to go on is the fact that I've managed to make 0ne diesel last 36 years and another last 29 years. Both tractors are in like new condition. Besides frequent filter changes, good oil, and never lugging them 'till they about died, I NEVER let them idle for long periods unless I HAD TO. I've been told diesels built a lot of excess heat while idling.

 

[kmdigital]

Everyone has their ideas and theories on this issue. All I have to go on is the fact that I've managed to make 0ne diesel last 36 years and another last 29 years. Both tractors are in like new condition. Besides frequent filter changes, good oil, and never lugging them 'till they about died, I NEVER let them idle for long periods unless I HAD TO. I've been told diesels built a lot of excess heat while idling.

Actually, no, diesels can get too cold while idleing for too long, because they burn very little fuel. This can result in something called "wet stacking". This is a condition where excess fuel/carbon builds up on the exhaust valve stems due to idleing for extended periods. Either put it on a high idle or shut it off if planning to idle for more than say 15-20 minutes.

Anyone with a diesel truck knows that it won't warm up much until you put the engine under load. Due to the cold engine, some fuel may not burn completely. And ideling is a great way to cool down a hot engine slowly rather than just shutting it off after a hard pull.

 

[chh]

My Cat diesel and MF(Perkins) recommend warming up for 5 minutes to ensure proper oil flow to the turbochargers before putting them under heavy loads. The also recommend a 5 minute cooldown period to allow the turbo's to cool. The manuals also recommend to avoid "excessive" periods low idle. I generally shut down if I'm going to idle very long. Especially if they haven't been running hard.

 

[NY_Yankees_Fan]

How about using it hard, i.e. a few hours of MMM use, do you shut it down after use or do you let sit at idle for a few minutes before shut down, this is for a non-turbo engine?

 

[Mighty Dodge]

I usually let mine warm up about 5 min. I'll shut it off if I'm going to be away more than 5 min or so.

M.D.

 

[chh]

If its been working hard I idle it down for 5 minutes or so. It is the best way to cool the engine down. That would be for any engine turbo'd or not. On the dozers I just start shoveling the dirt build up in the undercarriage out while its idling. If I've been mowing, brushhogging ect. I generally am out raking of excess grass off top or checking things over. The point being its not wasted time, just sitting in the seat listening to it run, its just part of the maintence time.

 

[garth466]

That makes sense. I have a extra key for when I'm running my truck hard in the heat for that cool down. I'll just lock it up and leave it run while I go have lunch.

I guess it also makes sense about diesels idling too cool. I'm just wonering if it is worse to stop and start the engine so many times during the day. I would never let it idle for long periods.

 

[jbrumberg]

If the temperature is below freezing I use my engine block heater prior to starting. Around 15 minutes at 30 degrees; around an hour at 15 degrees. I start at approximately 1500 RPM and increase to around 2000 RPM. I keep the clutch in for around 3 minutes and start working the hydraulics while the tractor is warming up. I let the tractor warm up for about 5 minutes before putting it in gear. When it is really cold out I will let the tractor idle for short periods of time for off-tractor activity. When it is warm out (above freezing) I will shut the tractor down for off-tractor activity. Jay

 

[Z-Michigan]

Actually, no, diesels can get too cold while idleing for too long, because they burn very little fuel. This can result in something called "wet stacking". This is a condition where excess fuel/carbon builds up on the exhaust valve stems due to idleing for extended periods. Either put it on a high idle or shut it off if planning to idle for more than say 15-20 minutes.

Anyone with a diesel truck knows that it won't warm up much until you put the engine under load. Due to the cold engine, some fuel may not burn completely. And ideling is a great way to cool down a hot engine slowly rather than just shutting it off after a hard pull.

I mostly agree on the idling - I have a diesel truck and a diesel tractor and neither one will get remotely warm after idling 5-10 minutes. I think we let the truck idle for 15 minutes once or twice and it didn't warm up by any useful amount. Now a few minutes of very light use and they will start warming up. Of course don't put any heavy loads on any engine (diesel or gas) when cold, but driving around slowly, doing light and easy loader work, etc. is ok.

I would disagree on the wet stacking issue. I posted a question about that a while back and some knowledgeable people, I think Dieselpower among them, noted it was hardly ever an issue and when it was it typically resulted from high rpm idling as might be seen in generator-set engines that have to be ready to provide full power instantly if power goes out. My JD dealer, who generally seems very knowledgeable, had warned of the risk of wet stacking which prompted my question, but it doesn't seem that anyone I've heard of has actually had an issue with it.

For the original question of idling between uses, I let it idle if it will be no more than 3-4 minutes and I stop the engine if I think it will be longer. Not scientific, just my "feel" for it. I would let it idle if you just stopped a really heavy task like plowing, to avoid having any hot spots in the engine where oil might cook from heat.

 

[sandman2234]

I never shut down a diesel without a few minutes of idle time, except at work, and then only if they monitor the idle time via computer. I got called into the office after being with my former company. They asked if my truck was ok, and how I liked everything. Turns out, I was fourth lowest in idle time for the company, and the three guys that beat me were dedicated guys that came home for the night. I was running over the road and stayed gone for up to 10 days at a time. Idle time was 4.1%, and they gave me a nice jacket. The year before I came to work for them, they had a contest for the lowest idle time and the winner got a new truck, and they also paid the taxes for him(income taxes so he could keep it, instead of having to sell it)They are used to idle time being around 25% and up for over the road drivers. Shutting down a diesel without allowing it to cool down really isn't good for it, if you have been working it! Most of the time mine doesn't get hard worked, so I don't have to sweat it too much, but still do it to keep in practice.
David from jax

 

[Highbeam]

I am of the crowd that will idle to cool and leave it idle if the off tractor job will be 1-3 minutes. However, my idle time isn't at low idle. I set the idle at just about 1400 rpm for a nice smooth humm and not a gurgly rough idle.

Pretty much everything is happier when the engine has a few hundred more RPM than low low idle.

My only problem is when I have been mowing pastures and things are starting to get warm because the radiator screens are getting plugged. You have to shut down the engine so that the fan doesn't suck all the chaffe into the coolers as you remove the screens for cleaning. I quickly clean the screens and replace them, then restart.

 

[automech]

I shut down if I plan on taking more than a few minute break, unless someone else is buying the fuel.

 

[RoyJackson]

Warm up is at a fast idle (1500 RPM) until the temp gage is in the green (or I'll operate it at no load for until the temp gage is in the green).
Idle after warmup is no more then 5 minutes. Any more then that I shut 'er down.

 

[john_bud]

. Proper starting and warm up for one and the other is let it idle or turn it off? If I am just stepping off I'll let it idle but if I am hopping off to use the chain saw or do something that may take 3-5 minutes I turn it off.

Is it better to shut her down for such tasks or let her idle. I know I would just be burning fuel, but is there more wear be the on and off?

Good answers so far. On start up, the hydro has a pre-charge pump that feeds fluid to the hydro pump. Typically, there is a filter after the precharge and before the hydro. Those filters have been known to blow if you rev too high while the fluid is cold. (cold is -10F and down). There is probably a warm up chart in your manual. When it's real cold, I use the clutch hold down hook and let it run at 1300-1500 rpm for 5 min or so before letting the clutch up. That warms the fluid up some keeping that filter from leaking. Then light operations until the machine is up to temp. I don't mess with the tractor unless there is an hour or more of chores to do. Just seems to be not worth it as the warm up time is so long.

I think you have a good feel for when to shut it off. Anything more than a couple minutes and you're just wasting fuel. When it's real cold, low idle has a chance of washing down the cylinders with raw fuel. That's a bigger concern in my book. Try and not let the engine run at under 1000 rpm unless it's warmed up. The thick white smoke you may see (not steam) is raw fuel.

Oh, don't forget to add cetane improver / anti-gel additive. Some will say that you don't need to do it, but I have been gelled up before and it ain't pretty. I like "Howes Diesel Treat". It has gotten be running before when PowerService in the white bottle let the fuel gel up (that was at a 2x dose of PS).

 

[Northland]

Good TBN advice again on this thread. Based on my cold weather experience this all makes a lot of sense. I wish I had known about the idling at higher RPM's sooner.

It is -17F (-26.8C) here this morning. Forunately it didn't snow here last night but we did get 6" on Thursday night. It was 1F (-17C) on Friday morning so I turned my block heater on and put my new Kats magnetic heater on the bottom of the hydraulic fluid intake/below the rear PTO.

I left both on for 2 hours and when I went out the tractor operated like it was summer.

Any ideas on the best place to put that magentic heater on the tractor for fastest warm-ups?

 

[pat32rf]

I find that the block heaters heat the coolant, not the oil. I would stick a magnet under the oil pan as well as the hydro resevoir for really cold use. I have a battery heater and block heater and Johnny always fires on the first roll. (If it doesn't its because the fuel solenoid is stuck again but this seldom/never happens if its been plugged in for more than a few hours, even at -25C) I don't think my preheat has ever worked since new and I don't worry about plugging in unless it colder than -10.

 

[Builder]

Instant shut down on a turbocharged diesel engine is bad because the oil in the turbocharger bearing galleries will be left stagnant in them and the excessive heat from the turbo turns the oil into a "coke"-like substance. This will in-turn trash your turbo bearings and cause premature turbo failure.

300* is the old rule of thumb for max shut down temp. If it really concerns you, get an EGT gauge and drill the probe into your exhaust manifold and install the gauge on your dash. Most all my diesel trucks have one. Many larger pieces of equipment have them.

Not as important on a naturally aspirated diesel, but I would still idle it down a few minutes to even-out the hot spots.

 

[D7E]

It's always good to idle em for a while when starting and stopping but too much aint good ,I don't like to see more than 1/2 hour depending on the amount of hard work it'll get to compensate .
In our -30 winter days i let it idle for up to 1/2 hour to get some heat into the rear end and take some strain off the hydraulics ,In these temps a loader wont lift until oil is warm (without doing damage).

 

[nosliw]

i just fire it up, let it run for 30 seconds or so, the take off. i keep the rpm's around 1300 and drive slowly (usually 4th or 5th).

i won't run into a pile or do anything hard until i'm at full operating temperature.

if i have to attach an implement, i'd fire up the tractor and drive over to the implement and by the time it's hooked up she's good to go (usually). i keep them on uneven ground so i usually struggle with them for 4-5 minutes