Correct engine idle speed during warm up??

[ray66v]

This is very misleading and inaccurate. Diesels only fire from the heat of compression. If they cannot produce a high enough compression temperature they will not fire wether there is fuel or not. It has nothing to do with being "lean". They do not run "lean" like a gas engine does, they ALWAYS have excess air, but are not "lean" in the sense that it might prevent them from firing or because it is the wrong mixture. There is always an excess of air unless they are running at full throttle. Rich and lean has nothing to do with starting a diesel like it does on a gasser and adjusting the throttle does not change the mixture. As long as they are getting enough fuel to produce the energy to run and they are producing enough heat, they will start. Diesels cannot warn up very well because they are usually quite massive and they always have an excess of air being pumped through them. This extra air has a cooling affect. There is very little extra heat being produced, and what there is is being sent out the exhaust instead of into the cooling system. You don't have to have a diesel fully warmed up to put it to work. A light load after 30 seconds or so will help it warm up and reduce condensation. Running it for long periods cold is more of a problem because it builds up carbon, causes a lot of condensation and wastes fuel. The condensation is water that is not a lubricant. Imagine the rings running up and down the cylinder walls lubricated by water. It's better to get it warmed up soon with a light load and get the oil to it's proper viscosity.

In Alaska, on the pipeline, many diesels were allowed to idle for long periods to warm them up, or keep them warm and ready to use. This caused a lot of engine failures and extreme carbon build up. It's much better to not baby a diesel. Get the oil circulating, which only takes a few seconds, and then start giving it a light load so it can produce some heat, stop condensing and stop producing a lot of cold carbon deposits. Running cold is the problem.

Thanks for once again proving my point, you can post the sky is blue on TBN and someone will disagree with it, and tell you it's wrong.

Sorry you don't like the terminology I used, or the way I explained it, That doesn't change the fact that if you don't add more fuel in cold weather the majority of these engines won't ever start.

Though I never suggested a particular amount of time to warm an engine, you go on as if I did. And suggest 30 seconds will do. Many engines out there are not in perfect condition, and absolutely will not run well at all, with 30 seconds of warm up in very cold weather.

Sorry, I did not write a book here for you to be more clear, However, I also did not ever suggest cold idling. But I did suggest the opposite.

You should take up your concerns about warming the engines too long, with every manufacturer who sells tractors with hydrostatic transmissions. They require as per their manuals, as much as 30 minutes or more of warm up in very cold weather.

Since the only good way to remove the moisture from an engine is to heat it, the high speed idle is not going to produce more moisture than it removes.

 

[Raspy]

ray,

I guess you misinterpreted my comment. I didn't mention the color of the sky. My comment to you was about the concept of a lean mixture in a diesel. That's it. There's an important difference between the amount of fuel and the "mixture". Not the same thing. You can call it a lean mixture if you wish, but that is misleading concerning diesels because it's not the same thing as in a gas engine where lean vs rich actually means something and where the mixture must be richer for starting. More fuel is needed in a cold diesel because cold combustion is poor next to the cylinder walls and a cold engine has much more friction. It's hard to get the fire started because the combustion chamber surfaces are so cold and absorb the heat of compression. This is why direct injection engines start easier than pre-combustion chamber engines. Once started, more power is needed when cold and that simply means more fuel, the air is already there in excess and already hot when the atomized fuel arrives.

You're right, the only way to get moisture out is to get the engine up to temp. Idling cold produces moisture and is very slow at heating. Long term idling means long term moisture and more carbon. Working it lightly, after a short while to get the oil circulating, heats it much more affectively and sooner. It saves fuel and gets the oil to the proper viscosity sooner so oiling is better. Carry on and run yours anyway you see fit or as your manufacturer recommends. Sorry you think I'm concerned, I'm not.

 

[kevin37b]

Kind of like getting honey in the mood ain't it . Everybody has their own tricks .

 

[ray66v]

More fuel is needed in a cold diesel because cold combustion is poor and a cold engine has much more friction. More power is needed and that simply means more fuel, the air is already there in excess.

Technically, your statement is misleading and inaccurate.

Cold engines do not start hard because of poor combustion. Cold temperatures cause the viscosity of the fuel to become heavier. Thicker, fuel atomizes less efficiently, making the engine more difficult to start. Opening the throttle enriches the mixture of atomized fuel to air. When the amount of atomized fuel is high enough, there is combustion, irregardless of the temperature.

That's why a cold engine won't idle well, but it runs good at higher rpms. More atomized fuel to give better combustion.

 

[wmonroe]

Just for fun I did a cold start video of my two tractors this morning. This is the first time I've put videos on YouTube or on here so hopefully this works.

http://youtu.be/BPCrGFKWXkM

http://youtu.be/r2r-_gNYvLw

 

[JerryK]

Just for fun I did a cold start video of my two tractors this morning. This is the first time I've put videos on YouTube or on here so hopefully this works.

Ford 961Powermaster - YouTube

Kubota L5240 Cold Start - YouTube

I like the sound of the old Powermaster. Makes me want to go out an hole out my Mahindra's muffler.... [ nice barn... !!!! ]

 

[HillStreet]

Hey Ray,

I start mine at low throttle, then increase to about 1200 rpm and let it warm sometimes up to 20 minutes depending on how cold it is. QUESTION: does this also aid heating the hydraulic fluid and hydraulic pump? What is the best way to heat up the hydraulics before working it hard (bucket or blower)? Thanks

 

[RalphVa]

I don't think you'll get much warmup at anything short of about 1,500 rpm. Me, I NEVER EVER just let engines warm up. Start them and then work them at around 1,500 rpm initially.

My older (2004) tractor had to be started at about 1/2 to 2/3 throttle. Then I quickly shut it back to about 1,500 and went to work. This new one's idle speed is 1,575. It'll start there, and I can immediately go to work at that speed. (I've set the speed back to 1,500 on it now.)

Ralph

 

[vtsnowedin]

[

Hey Ray,

What is the best way to heat up the hydraulics before working it hard (bucket or blower)? Thanks

Turn the steering all the way to one of the stops and let the pump send the hydraulic oil through the relief valve for two to three minutes. Then you can work the loader all the way up and down a few times to give the pump something to do under light load and change the cold fluid in the hoses and pistons for warmer fresh from the pump. After that a bit of normal work will get everything warm quickly enough.

 

[RoyJackson]

Deere 4400 owner here...

Since I keep the tractor in an attached garage, it's not normally extremely cold...however, I do use the block heater on occasion (in the garage) and always use it if I do leave it outside in the winter months...

Once I cycle the intake heater, I start with the throttle at minimum until the oil light goes out (2-3 seconds) then increase the RPM to about 1500 and move the machine out of the garage. Then, there's 5 minutes or so of 1500 RPM idle before I start working...but no hard work until the temp gage is at the normal temperature (about 1/4 up the range is where it stays)