Long idle times

fatboycowen · Dec 4, 2015

I recently installed some LED lights on my tractor. I use the tractor for moving firewood (one of the uses). Since it gets dark so early, I've been moving and splitting at night. I have no other light source near the splitter than the tractor.
Is there anything wrong with letting the tractor idle while i split a bucket load, so i can run the lights? I realize my tractor counts hours regardless of RPM. I don't really care that I'm putting hours on it, as the hours are already high (1260 now). I'm also not too concerned with fuel use.
Do long idle times hurt anything? It's probably 15 minutes or so at a time, as a guess. Maybe it's less. Then, up to 2k rpm to move to the wood pile, and stack the wood.

A separate question: How long should i be warming the tractor up on idle on colder days (say 20 to 30 degrees), before raising the RPMs to run the tractor?

Trials · Dec 4, 2015

Is it a diesel engine? My father-in-law always said that the hardest thing on a diesel was the moment of start-up, when there was no oil pressure to the bearings. By that logic it is better to leave a diesel engine at idle rather then turning it on and off frequently. Warmup time varies depending on many things such as the amount of water condensation or frost inside the engine, but basically you just need the engine oil up to operating temperature and you are good to go. Having a heater on your engine oil pan will greatly reduce the need for extensive warmup time.

20 to 30 degrees, heck that's not even cold. Once you hit -40 even metal becomes brittle, so be careful if you ever have to deal with that.

Batteries also operate at a much lower efficiency in extreme cold. In the range of 30% less efficient, so watch out for that when you are operating them at discharge. Most engines are equipped with alternators that do not generate much charge at idle, possibly even resulting in a slow discharge situation. ymmv.

Billrog · Dec 4, 2015

If I were idling for extended periods of time I'd set up the idle around 900 or a little more.

CCWKen · Dec 4, 2015

Check to see if the alternator is charging at idle. Many don't. If it isn't, you'll be running the lights off the battery. You might as well turn the engine off and save fuel. I just found out while diagnosing a dead battery that my 3910 doesn't start charging until the RPM is up around 800-900rpm. (The tach doesn't work so I'm guessing.) And I've owned it for about 10 years! All those times I've run it for exercise during non-use periods didn't help the battery. I'd run it at fast idle until it reached operating temperature then shut it down. I do this with all the equipment.

One of these days I'll get the new dash in it and get edgeumecated with some idiot lights. :ashamed:

Gary Fowler · Dec 4, 2015

Most diesel engine idle at 900 RPM, so I usually set mine just above Idle at 1000 RPM. I have not seen any problem doing this for extended periods of time. Many TBN contributors warn of "wet stacking" and other problems with long idle times but for most engines, anything less than 30 minutes of idling is not going to be a problem.
As mentioned, you may need a bit more than idle to recover the battery energy used if you have a large drain with many lights. Many CUTs have small alternators in the 40 amp range so idling may not produce the amps required to keep you battery charged if you are drawing a lot of amps.

As for warmup time, it varies a lot with temp. Many tractors have a warning light that indicates cold hydraulic temps and should not be moved at least till that light goes out, but this is usually just a few minutes or even seconds if the temps is not that low.
If you routinely use your tractor in temps below freezing, you should consider putting in a block heater so your engine is warmed prior to starting. If you have this, you could start moving within a minute or so of cranking. When I lived in Northern Alberta Canada where the temps were -30 to -40 C during most of the winter. I used a block heater AND let my engines warm for 10 minutes or so just to defrost the windows and warm the cab in the mornings. There is really no requirement to let an engine get to full operating temp before moving out (many diesels will not get to normal operating temp when idling regardless of the time allowed), just keep the RPMs down to around 1500 and drive off slowly after a 5 minute warm up. This will allow the engine to warm more efficiently than it will just setting still. As long as the oil is circulating properly after startup, that is really all you need.

For my location, about 1 minute @1000 RPM is all that is required for warmup since it rarely gets much below freezing. I never idle up above 1500 RPM for at least 5 minutes which is what it will usually take me to get out of the shed and to any work area anyway.

farmer2009 · Dec 4, 2015

Most Diesel engines have a bad vibration at an idle. This results in water jacket pinging. Eventually causing holes to be worn in the ends of the water jackets. Mainly seen in the cylinder walls. It's caused by the water moving back and forth against the cylinder wall with the vibration. Takes many hours to form. To avoid bump throttle till engine smooths out say 1000-1200 rpm.

PILOON · Dec 4, 2015

Often when very cold my warm up consists of moving at just a tad above idle (1200rpm) in the lowest gear setting.
Gearing being what it is I figure there is really no strains on anything and that actually I help by having all the fluids circulating without straining.
I would do this only on flat areas as climbing a hill would lug the engine.
I also exercise the loader a few cycles to warm up the oils.
Oh, I do idle some, but not a whole lot, and add that I am usually plugged in for 1-2 hours prior.

fatboycowen · Dec 4, 2015

Thanks for all this. I believe my engine (Diesel) idles at 1000 per the book (I swear i've read it, but can't find it now), which is about what the tach shows.
I'll bump up the idle for longer periods of idle, and i'll check the charge at idle.
The alternator is 50amp.
The lights are LED and don't draw much. I believe all of them will draw about 10amps total (iirc), but i usually don't run them all at once.

Bird · Dec 4, 2015

I had a neighbor who had the opposite problem from cold. He was in the hay business, working alone most of the time, and had two air-conditioned John Deere tractors. Now if you shut one of those things down, out in the sun, it gets really hot in that cab in the summer. So when he went to bale hay, he used both of those tractors; one with the baler, one with the rake. So he'd rake awhile, bale awhile, rake some more, bale some more, etc. BUT he left both tractors running and the air-conditioners running all day; the one he wasn't using sitting there idling to keep the cab cool.