idle speed

[warcloud]

I would like to know your thoughts on leaving tractor running at idle speeds for long period of time. I understand that it does not hurt to let a diesel idle. true or false

 

[cheesehead]

False. The efficiency of the injectors in these small diesels at idle is very low, which results in more unburned fuel. Some of that unburned fuel ends up in the engine's oil, which breaks down the oil.

 

[TripleR]

Guess it depends on the size of diesel. I never let my BX2660 idle, but have my bigger tractors 60 and 80 hp.

 

[radioman]

how long is the idle ? why are you idling other then need to let it run in the wintertime when temps is below 0 when you are using the tractor ?

If I just started up the tractor and its hasnt come to engine temp, I rather idle it a bit till it does before shutting off to keep moisture out of the oil.

 

[Thomas]

Depending on what I am doing..if off the tractor 10 mins or so low idle..longer shut off tractor.

 

[Tul01]

I have also wondered this, so if idle speed is inefficient (ours idles at about 800 according to the tach) would say idling at 1000 bring up that efficiency to avoid the issue? The engine seems to start "working" at about there so I'm assuming it is running more efficiently? also assuming then that an efficient 1000-1100 would be burning about the same fuel as inefficient 800? In the cold winter have to leave it running at about 1400 or it cools right off.

thanks
Brent

 

[GregH]

I would like to know your thoughts on leaving tractor running at idle speeds for long period of time. I understand that it does not hurt to let a diesel idle. true or false

According to an article in Progressive Farmer some time ago, both Cat and Cummins advised against prolonged low rpm idling. Diesels at idle run very lean thus the engine cools and allows unburned fuel to contaminate the oil resulting in excessive wear. If idling more than 5 minutes shut it down or use fast idle as some of the newer big rigs are designed to do.
Hope this helps
Greg Harrison

 

[sw03]

Make take is I have NOT had more then avg wear idling; at least the UOA's show I am fine. My take is do what you want and have fun. My bx24 idles at 1150 +/-...YMMV..

Unless you have an injector issue, I would love to see UOA's (from idling) showing fuel more then 0.75 to 1%

 

[Chilly807]

I'll let mine idle for at most 5 minutes once it's at operating temperature, other than that it gets shut down.

For me it has nothing to do with fuel efficiency or not wanting to pay for the fuel wasted idling. Any engine at idle (no load) has relatively cool cylinder temperatures that can't burn fuel properly, which leads to carbon buildup, sticking rings, etc.

Same thing with a wood fire in a stove, if it burns too cool you get creosote building up, with a hot fire all that's left is a fine ash.

One case where you DO want to have an idle cooldown period is on a turbocharged engine. If you've been working it hard, let it run at idle for 5-10 minutes before shutting down. This lets the turbo cool down gradually while fresh oil is still flowing through it, otherwise the heat left in the turbo will cook what oil is left in it.

Chilly

 

[DmansPadge]

Yeah it's really not good for them. If it's gonna be more than a few minutes it's probably best to idle it up or just shut it off. Diesels aren't made to sit and idle all day like some believe.... they like being worked!

 

[scotty088]

I agree with chilly,Also most 3 cyl diesels in the 20-35 hp range vibrate violently at idle and lower rpms causing damage to engine mounted brackets and other components.With throttles bumped up these engines smooth out remarkably.
Scotty

 

[whistlepig]

If something takes longer than 10-15 minutes I shut the tractor off. If the wind chill is -25 degrees I let the tractor run. I have no desire to work on a non-starting tractor in -25 temperatures. Better if it fails to start in the garage where all my tools and heater are.

 

[BotaBigot]

Make take is I have NOT had more then avg wear idling; at least the UOA's show I am fine. My take is do what you want and have fun. My bx24 idles at 1150 +/-...YMMV..

Unless you have an injector issue, I would love to see UOA's (from idling) showing fuel more then 0.75 to 1%

Great answer...with data to back it up...

My decision is based on restart "wear" vs letting it idle...