Extended idling vs switching on and off

[GManBart]

The only time I shut down my diesels is when I know the idling period will be more than maybe 20 minutes. I definitely don't shut down if it's only going to be 5-10min between tasks, and I really don't care if it sits at idle for half an hour or so...the difference in fuel use is negligible. The debate will go on forever, but the one thing that really isn't in question is that starting is when most wear occurs, because things are spinning with zero oil pressure for a short period of time. Yes, there is residual lubrication if the engine has run recently, but it's not as good as having full pressure lubrication to keep bearings from contacting crank journals etc.

 

[sixdogs]

I read in some Deere educational article that said if you're going to let it idle for very long to raise the idle to a "fast idle". Not being exactly sure what that meant, I bump mine up by a few hundred RPMs and it seems to work.

 

[RoyJackson]

I read in some Deere educational article that said if you're going to let it idle for very long to raise the idle to a "fast idle". Not being exactly sure what that meant, I bump mine up by a few hundred RPMs and it seems to work.

I never idle my tractors at less then 1200-1300 RPM and most often it's 1500 RPM...this includes the warm up period.

Your post brings up a good point about fast idle, BTW.

 

[PapaPerk]

If it's not going to set too long (more then 5 minutes), I leave it idling....more then 5 minutes, I shut it down.
This is after it's warmed up, of course...

What Roy said!

 

[corl]

When we visited Dawson City in the Yukon they start their diesel dozers in the winter and never turn them off til spring. A D9 was said to use 5 gallons of fuel an hour at idle. Have to find gold up there just to keep them running.

 

[hhsco]

This is what the manual for my (relatively) newer JD tractor says:

Avoid Idling the Engine

Allowing engine to idle at low rpm uses fuel inefficiently, and can cause a build-up of carbon in the engine.

If tractor must be left with the engine running more than three or four minutes, minimum engine speed should be 1200 rpm.

Seems reasonable. Also doesn't seem like your tractor is gonna explode from carbon buildup if it runs at low rpms every once in a while.

 

[Blade Breaker]

Anyone ever had an engine fail from extended idling? Didnt think so. Idle as needed it will be fine. Starters do wear out after so many uses.

 

[PapaPerk]

Anyone ever had an engine fail from extended idling? Didnt think so. Idle as needed it will be fine. Starters do wear out after so many uses.

Many modern Diesels are so efficient that they can have issues from excessive idling. Cummins for one... They can have issues with fuel washing down cylinder walls.

If it sits longer than 5 mins after warm up I shut it down.

 

[Blade Breaker]

I have read about this theory also. That is why I ask if anyone has ever had a problem because of idling. Think of all the trucks sitting in traffic jams every day idling. Think of all the construction sites with machines idling more than working. If this theory was true wouldnt there be lots of failed diesel engines?
A utility tractor idling occasionally should not cause any problems. IMO

 

[skyhook]

I start mine and let er run, let run, let er run,,
until I'm done doing what I needed doing.
1300 rpm's always, at idle.
Sometimes, I let er run, just to hear it run.