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.