Idle or shut down?

[Camo]

I got my Kubota B5200 a couple of months ago, and came upon a question. Is it better for the diesel tractors to sit and idle while you work on something, say like cutting firewood, or should I shut it off and restart it when I'm ready to move again. I'm not concerned about burning a little fuel if idling is best, but I want to do what is best for the machine. Thanks!

[3RRL]

You'll get a few different responses, I'm sure, but I find if I'm going to so something for more than a few minutes, I shut the tractor down... Something about "wet stacking" if left idling too long. Plus, if you're going to have it idling for any extended period of time it doesn't hurt to save the diesel at today's prices.
For on and off the tractor quickly, I leave it idling of course.

[machmeter62]

My personal "bench mark" when the engine is warmed up; five minuutes or more I shut it down. They burn very little at idling (100 to 1) air/fuel ratio, but there is still a lot of moving parts turning? I have a 30 yr old Kubota L295DT 5000+ hours with absolutely no failures in electrics or mechanical systems, but I don't beat-it either, and change the fluids and do the preventive maintenance also.

I live in a mild climate also (Calif.), but cold weather would be another factor for leaving it run? You should find yours very reliable too.

[RoyJackson]

About 5 minutes here too...anymore then that, I shut it down. Also, my idle RPM is 1200 RPM or so. I never idle it at less then 1000 RPM.

[GregH]

Originally Posted by Camo

I got my Kubota B5200 a couple of months ago, and came upon a question. Is it better for the diesel tractors to sit and idle while you work on something, say like cutting firewood, or should I shut it off and restart it when I'm ready to move again. I'm not concerned about burning a little fuel if idling is best, but I want to do what is best for the machine. Thanks!

About 3 years ago I read an article in Progressive Farmer that had asked the question to Cummins and Cat. Both companies stated that after 5 minutes of idle, shut it down. Main reason being, at idle a diesel burns very little fuel and the engine temps drop below the optimum point. This causes unburned fuel to puddle in the crankcase and contaminate the oil. THis in turn accelerates wear.
When the major makers speak, we should listen.
GregH

[Soundguy]

Same here.. about 5 minutes is the max number.

That lets me hop down, open gates, and pull transport lock pins on my mower.. etc..

soundguy

[ray66v]

Originally Posted by GregH

Main reason being, at idle a diesel burns very little fuel and the engine temps drop below the optimum point. This causes unburned fuel to puddle in the crankcase and contaminate the oil. THis in turn accelerates wear.
When the major makers speak, we should listen.
GregH

Someone should tell this to the applejacks that sit with their diesel idling in front of the doors to the store, while their family shops for 30 mnutes.

I have to wonder about this, Trucks are often left idle overnight, construction equipment often is idle for hours. I worked at the airport when I was young, the diesel equipment was never turned off in the winter, (left idle all night, every night).

Clearly a running engine will wear faster than one that is not running. I'm just wondering about how big a deal is the accelerated wear aspect. Does that mean the engine will only last 300k miles instead of 350k?

There is also a certain amount of wear from a cold start to factor in.

I have an engineer friend, (which is odd because I dislike engineers ), who worked at TRW, on failure analysis of engines. His wife is also a retired petroleum chemist. I am going to see them today, so I will get their opinion on this.

I let my tractor run at idle for 5 minutes to cool down after working it, then I shut it off.

[257NH]

I usually will let it run for 5 minutes also,More if its cold,say 20 or less degrees.I also will let it cool down for a bit after its been worked hard,longer if the motor has a turbo.
Brian

[mjarrels]

I shut down the key start tractor and idle the push this, pull that, turn switch tractor.

mark

[daTeacha]

This may have no bearing on diesels, but letting a gas engine for more than 10 seconds uses more fuel than shutting it down and restarting. This is for modern computer controlled injected engines, not carburetor equipped older ones.

More fuel burned means more pollution in the air, too.

I think the 5 minute rule of thumb for diesels is pretty reasonable. We have some kind of limit on idling school buses and delivery trucks near the school building, but I don't know what it is.