Diesel Warm-Up -- How Long -- Why?

[SPYDERLK]

My '99 Powerstroke has an enrichment feature for cold weather that helps it warm up even at lower rpm. Remember diesels run with a wider range of fuel/air ratios then spark ignition engines so the peak gas temperatures in the cylinders has a wider range of variation. Increasing the fuel to air ratio will increase the peak gas temperature.

How in the heck does that work?:confused2: Diesel should just rev up with more fuel since its full air allthetime.
larry

 

[RoyJackson]

...
Do I need to change my tractoring habits? I always thought that one of the positives of a diesel tractor was that you could let it sit and idle all day if you wanted to - not that I would do that of course.

Like I wrote...I shut it down if it's going to be idling more then 5 minutes...no good reason, but that's what I do...


So, why do you write this:

not that I would do that of course

 

[RoyJackson]

Originally Posted by Jerry/MT
My '99 Powerstroke has an enrichment feature for cold weather that helps it warm up even at lower rpm. Remember diesels run with a wider range of fuel/air ratios then spark ignition engines so the peak gas temperatures in the cylinders has a wider range of variation. Increasing the fuel to air ratio will increase the peak gas temperature.

How in the heck does that work?:confused2: Diesel should just rev up with more fuel since its full air allthetime.
larry

[/QUOTE]

I'm not sure what he meant either, but I have seen diesel trucks with a device to up the idle for a period of time...nothing to do with enrichening the mixture though...just increases idle speed.

 

[Gary Fowler]

I am not sure about harming diesels by letting them idle after warmed up. Truckers used to let them idle all night at truck stops to keep the Ac or heat up while the slept and all the truck stops had them idle before the EPA got involved. Probably didnt get over 2-3 million miles out of them though so maybe that wasnt good for them. We had an AC D17 tractor that we idled for at least an hour every day at lunch because it would never crank and had to be pulled off just about every time. We pulled it off in the morning and killed it at night. It never had a problem with the engine in the 10 years that we had it. As for warm up, any engine needs proper warm up prior to heavy loading. In frozen north, block heaters are standard fare on all engines to make them easier to start for one thing and decrease the wear as secondary factor.
One poster mentioned that gear drive tractors dont need warm up when block heaters are used. That may be acceptable for the engine, but the hydraulic system still needs to be warm before hitting it hard. My LS has a warning light that stays on till the hydraulic system comes up to temperature so I leave it at about 1000 RPM till the light goes out which is usually about the time I get from my barn to the work area. I dont have the super cold to worry about though and a couple of minutes of standby at 1000 RPM is about all the engine gets in winter and less in summer.

 

[DennisFolsom]

Warm her up...applies to everything. Ask your wife, does she liked to be warmed up first? The answer is yes. A little foreplay will go a long way so does your tractor. I bet you won't forget now.

Good luck

Yes! A little gentle exercise really helps her to be properly lubed and ready to go at it! :laughing:

 

[Willl]

Increasing the fuel to air ratio will increase the peak gas temperature.

I thought it was the other way around ?

 

[Egon]

The Comercial Trucks now may have an in line fuel fired circulating heater to keep all warm.

 

[Redneck in training]

That is a long warm up!! Your manual actually says that?

My says that too. Before I shut the engine down I adjust the throttle to about 1500 rpm. So when I start it next time it goes to 1500 first to get oil quickly to the engine. Then I either adjust the throttle to Idle at about 1000 or start moving the tractor where I need to go. When the temp needle starts moving from the low stop I increase the speed to about 1800 - 2000 for few minutes to allow the engine reach normal operating temp and then go to full load. When it is cold the engine could idle forever and the temperature gage will not move from the low stop.

There two main issues associated with the warm up:
1.) The tractor parts reach correct tolerances only after the machine reaches normal temperature.
2.) Oil can be damaged while operating at high speed while at low temperature. When it is cold and the oil has high viscosity the normally long molecules might be shredded in bearings and the oil will lose its capacity to separate moving parts of the machine.

I commission rotating machinery for living. Every rotating machine such as turbine, compressor, pump, generator etc has a temperature interlock preventing start until the oil temperature reaches minimum level. There are heaters in the oil tank.

 

[Dave5264]

I typically let my Montana (Romanian UTB Manufactured with the 3cyl Fiat Deisel - AKA the old 60's Universal type tractors) warm up for about 5 minutes before it get on and drive it. By the time I get to where Im mowing or working (a few minutes) the temp gage has moved up a bit and I can distinctly hear the engine change tone and smooth out as it reaches operating temp. I wait for that before I put it under load.

I have no idea what is happening to change that sound in the motor, but its done that from Day 1 (brand new in 2008), and so I follow that routine.

 

[SPYDERLK]

I typically let my Montana (Romanian UTB Manufactured with the 3cyl Fiat Deisel - AKA the old 60's Universal type tractors) warm up for about 5 minutes before it get on and drive it. By the time I get to where Im mowing or working (a few minutes) the temp gage has moved up a bit and I can distinctly hear the engine change tone and smooth out as it reaches operating temp. I wait for that before I put it under load.

I have no idea what is happening to change that sound in the motor, but its done that from Day 1 (brand new in 2008), and so I follow that routine.

Our Kubotas have a throttle advance that jacks idle rpm to about about 1100 when cold. And the engines tap/knock a little and taper off to normal after a minute or two. The Mahindra, otoh, has an automatic injection timing advance that operates for a few minutes after starting. ... hot or cold I think. The engine is mechanically louder and can produce more power [warm] while this operates, and quiets suddenly [and loses a little power] as timing goes normal. That sounds like what you have too.
larry