Oil & Fuel Diesel Engine operation

[WVBill]

Amazing how one thread feeds off another on this forum... here goes..


On the Rediculous Use of Tractors thread several of you describe tasks that probably don't take five or ten minutes. I was ondering about those kinds of tasks.

I was also wondering about tasks in which I'm using my tractor for a lengthy time (say an hour or two) but have to occasionally to do hand work for five or ten minutes.

I know there have been similar discussions in the past, but not in this context.

What, if any is the effect of those two kinds of operation on a diesel engine?

Is a five-ten minute operating period enough to get the diesel up to full operating temp? Is there any ill effect of not letting it warm up fully? I know it's not supposed to be good for gasoline engines, same for diesels?

On the flip side, should I shut the tractor down while doing off-tractor work for a few minutes or let it run? What's better for the tractor? I see that they let diesel busses and trucks run for extended periods - but those engines are much larger.

I just want to treat my 22 year-old right.

Bill

 

[huckflynn]

The 5 minute engine warm up which Kubota recommends is the main reason I don't use the tractor to haul the garbage. I may get more lax with this rule after I get beyond the break in period, but I want to make sure my investment gets off to a good start. To quote Kubota:

"For five minutes after engine start-up, allow engine to warm up without applying any load, this is to allow oil to reach every engine part. If load should be applied to the engine without this warm-up period, trouble such as seizure, breakage or premature wear may develop."

They continue about the hydraulics and warm-ups:

"Hydraulic oil serves as transmission fluid. In cold weather, the oil may be cold with increased viscosity. This can cause delayed oil circulation or abnormally low hydraulic pressure for some time after engine start-up. This in turn can result in trouble in the hydraulic system."

To avoid problems they recommend 5 minute warm-ups when the temperature is above 32. From 5 to 10 minutes between 32 and 14 degrees. 10 to 15 minutes between 14 and -4 degrees and "More than 15 minutes" when the temperature is below -4. (All temps Farenheit)

Huck

 

[Bird]

WVBill, you're right; this has been discussed in the past, and you'll probably find different opinions. Personally, I hate to start any engine, gas or diesel, and not let it run long enough to thoroughly warm up, dry out any condensation, etc. and I think that probably takes 20 or 30 minutes at operating RPM, not just idling. However, as with a car, I may start it and run it for very short periods of time occasionally.

There has been a lot of discussion of diesel engines running too cool at "idle" and I think the concensus of opinion is that, if you are going to leave it idling for any length of time, leave it at a pretty fast idle. Wonder if that's part of the reason my B2710 came with the idle set at about 1200 rpm? although someone said it was to meet California emission standards. Of course, I backed that idle down to 800-900 rpm.

At least one guy told me one reason to leave the diesel idling is because "diesel is cheap compared to starters." I don't entirely buy that, but guess it could be a minor consideration. Of course there are reasons to leave big trucks running that don't usually apply to our tractors, i.e., to keep air-conditioning running or a concern that if it's shut down, it might not start when you're ready to go again.

I have one neighbor in the hay business who has 3 air-conditioned John Deere tractors and when he's working alone, he'll have the rake on one tractor and the baler on another; he'll rake awhile, then bale awhile, rake more, etc. And he never shuts down either tractor, but that's because it's hot in Texas and he doesn't want to shut down his air-conditioners.

So . . ., my personal unscientific opinion. Run it long enough to thoroughly warm it up when you start it, at least most of the time. If you're going to leave it idling for more than 2 or 3 minutes, open the throttle a bit to make it a fast idle. Then I don't think you can hurt it by leaving it on a pretty fast idle for extended periods, but if I'm going to be off mine more than about 5 minutes, I usually just shut it down.

Now some of you other guys tell us what you do and why.

Bird

 

[dmccarty]

My JD manual says to warm up the tractor for a couple of minutes before operating. I don't remember the manual specifing what a "couple" means so I warm it up for two minutes before driving off. By the time the tractor gets from its hidey hole and to where I'm working its well warmed up. I take a nice semi-slow drive to allow everything to get to operating temps.

The manual also states that extended idling is a bad thing. However, they don't define "extended" nor do they say why it is a bad thing.

I assume the extended idling allows condensation to build up causing corrosion.

Hope this helps....
Dan McCarty

 

[glennmac]

I don't worry about it. Never did with cars, either. I figure anything that's supposed to be strong enough to terraform the earth doesn't need the engine mollycoddled. I idle for a minute or two and then take off slowly. I'll idle longer in the cold. While working, I have sort of a 5 minute rule like Bird, but it really has nothing to do with concern for the engine.

From reading here, I'm sure others think differently and will speak up.

 

[geneP]

I'll add my non-scientific opinion and practices. Like most stated thus far, I too give my tractor and vehicles a short warm up before applying load. The colder the weather and oil, the longer the warmup. I've always heard that by far the most wear occurs on a cold start, and therefore make a conscious effort not to start one unless I'm gonna run it long enough to stabilize the temps and burn some of the condensation out of the oil. For those who trade tractors at 1500 hours or vehicles at 60,000 miles, these practices probably won't buy them any less mechanical problems. I usually keep a car/truck 150,000 or so miles and have never worn out a tractor (always get bored and want to try another one), so I try to balance long life objectives with short term use for the vehicle.

Whew! That's a lot of verbage for a worthless opinion

 

[DVerbarg]

Bird,

On some of the larger JD tractors, such as the JD4040, the operators panel has BIG yellow warning stickers to remind the operator to let the engine run at a slower idle for awhile after use at normal RPMs. I wish I could remember the language used but the general gist is that the turbocharger/turbine needs to cool down before being shut down.

DaveV

 

[huckflynn]

<font color=blue>Whew! That's a lot of verbage for a worthless opinion</font color=blue>

I thought it was a great use of words and a valuable insight. One of the main reasons I opted to buy new was that I did not know the care given to the used tractors I looked at.

A well cared for tractor with many hours on it could be a better value than an "almost new" tractor that was mishandled.

Huck

 

[Bird]

DVerbarg, I didn't address the topic of turbochargers since most of us are using "compact" tractors that don't have turbos; however, you're certainly right. I've heard that there may have been some changes in the newer turbos, but don't know. My understanding is that basically, the turbo is turning at an ungodly rpm (20k or so?) and it's bearings are cooled by the motor oil and can get very hot. Therefore if you have been running a turbocharged engine at operating speed, then abruptly kill the engine and stop circulating the oil, the oil that is there at the time is going to get overheated. So, you definitely want to let a turbocharged diesel idle for some period of time before shutting it down. Anyone know anything different? I've never actually owned a turbocharged machine personally. Now, for me personally, I never shut any engine down immediately when it's been running at operating speed; whether car, tractor, or lawnmower. I back the throttle down to idle for at least several seconds, preferably a minute or so before killing the engine.

Bird

 

[M. Sullivan]

Bird is right on target with turbo-diesels. In addition to the points he mentions, other key reason is to allow the block/heads etc. to cool. Too rapid a cooling rate can result in warping--especially over time. Keep in mind the block and heads are massive blocks of iron (ref. Ford Powerstroke) and the stresses developed as the pieces cool is considerable. Each piece cools at a different rate. Hence the lower the shutdown temp. the better. Talked direct with turbo-diesel engineers on just this point. I idle 5 min. after getting it home, and even sit in parking lots--but mine is more or less a pleasure vehicle so not a big inconvenience. Major requirement imo when driving highway speeds in the summer if you plan to get 200k+ miles out of one. Would guess less of a factor with small diesels, but I do it anyway.

This post does drive a question wih winter approaching here. Is it a problem to start the tractor and immediately v. slowly pull out of the garage at lowest rpm, when it's say 10F. Have not so far, but thinking I'll gas the family if I leave it sit in the garage for 5 minutes. Actaully have been half heartedly looking for some flex pipe to route a vent outside. Thoughts??