Idle Speed for Tractor Warmup ?

[AndyMA]

New Holland suggests idling the TN75 turbos at idle for 1 1/2 minutes prior to shutdown so that the turbo oils itself. I idle my 2120 and Tn at min throttle for a minute or two and then use it gently for the first few minutes during the warm seasons. In the winter I idle both of them at just above min (probably about 1200 rpm) until the loader and hydroshuttles seem to work right.

Andy

 

[AndyMA]

After reading this post and thinking about what I had written above I wondered if New Holland actually had something to say on the subject.

In my TN manual, I came across the following statement. " NOTE: Before using the tractor below -18 degrees C (0.4 degrees F) start the engine and leave to idle at a speed of 1300-1500 rpm for approximately 5 minutes. This will allow the gear oil to reach operating temperature"

Andy

 

[PineRidge]

My TC-40D isn't even broken in yet at about 42 hours. The dealer instructed me not to let it idle for long periods of time below 1500 RPM. I use that RPM for about a 5 minute warm up. He said at the 1500 RPM speed the filters were better prepared to do their jobs. I come back to idle for a minute to shut down the engine.

 

[Dave___in___CT]

Thanks for the comments...

I understand it's not so good for a tractor diesel to idle at low RPM's for very long... that's why I've been using 1200-1300 RPM for warmup... 1500 might be better...


Dave...

 

[cowboydoc]

Dave,

Don't get confused on it. A higher initial warmup is not going to help you. The important thing is that you vary the idle from lower to higher as the engine is warming up. I would never idle a cold engine at anything more than the lowest idle setting. After a few minutes then move it up a little. Revving up a cold engine right away will only cause wear and tear on the engine not help it.

 

[BB_TX]

The manual for my JD950 specifically states not to allow it to idle for extended periods below 1000 rpm. It doesn't define what "extended period" is though. I am guessing this is to prevent carbon buildup from incomplete combustion at the less efficient low rpms.

 

[SacandagaBrad]

My TC24D came with an idle speed of 1100 rpm and I also thought it was a little high. But the manual says the low idle should be set between 1100 and 1200 rpms. I figure the higher idle speed allows for better oil circulation and maybe that is what the manufacturers are thinking. Maybe that is why the manuals recommend against low idle for extended periods as mentioned in this thread. When I start mine, I kick it up to about 1200 to 1400 for few minutes.

I think it is more important to have the proper oil and hydraulic fluid matched to the climate than worrying about a couple hundred rpms during the all important warm up period, assuming you keep it relatively low. There's not an engine made, 2 stroke, 4 stroke, gas, or diesel, that appreciates a 3/4 to full throttle start in the cold. I don't like hitting the ground running without my coffee either /forums/images/graemlins/wink.gif

As far as cool down, I alway thought that was for turbos as well. I would rather have the rpm up enough for circulating the oil rather than have a hot engine run with little oil getting to the top.

Brad

 

[johnday]

Most people do not realize it, but at idle speed a diesel will usually cool itself off causing condensation and other bad things to form in your oil. Mostly it is thought that you can idle a diesel forever, but if you plan on that, goose the speed up about 200-300 rpm. On alot of heavy equipment, trucks, etc you actually have an aux throttle not too much different from what is on our tractors, and on some, like the Ford Powerstroke it will do it for you below about 30 degrees F after you sit for a little at 700 rpm idle.

 

[Bird]

I agree, Brad. I might should have left the idle on the B2710 at 1200 the way I got it, but it just seemed to me to be revved up too much, especially when you first started it. So I started it at about 850, gave it just a few seconds to get the oil circulating and oil pressure up, then gradually increased the rpm. I never had a reason to leave it at low idle for very long at a time. Now of course, I live in Texas, can't even remember using my tractor in sub-freezing temperatures and only occasionally needed to use it in temperatures below 40 degees. So my "warm up" times were usually on the order of 2 minutes or less, although I didn't go full throttle for 5 minutes or more. And yes, the turbo is the reason for the "cool down" times, except I never wanted to shut any engine down immediately after running high rpms, whether car, tractor, boat, lawn mower, chain saw, etc. I always dropped back to an idle, usually for only a matter of seconds instead of minutes in most cases, before killing the engine. Of course when I drove a truck with a turbo engine, I let it idle a little longer before shutting it down.

 

[PineRidge]

<font color="blue"> except I never wanted to shut any engine down immediately after running high rpms, whether car, tractor, boat, lawn mower, chain saw, etc. I always dropped back to an idle, usually for only a matter of seconds instead of minutes in most cases, before killing the engine. Of course when I drove a truck with a turbo engine, I let it idle a little longer before shutting it down.
</font>

I agree with Bird. Give it a second or two to cool before shutting the engine down, it can't hurt.