Warm-up Time ?

[Highbeam]

I start it at a dead low idle, a single puff of black, then once the oil pressure light goes off in about a second I bump the RPM up to about 1300. No smoke at all. The engine idles smooth and then almost seems to unload after about 10 seconds as though the hydraulics have pressurized. Then I back out of the shed and let it warm up as needed for the job. If I'm just going to use the loader as a wheelbarrow to haul some firewood then I'll immediately drive over and load it. No real work to be done. If I am going to be running up to PTO speed and mowing a pasture then I'll let it get fully warm first.

I don't think that the engine needs to warm up before being loaded but I do think that the fluids need to be moved around and that some warm up time is better than no warm up time. Now another question would be how many of us allow the engine to cool down before shut down?

At all temperatures I allow the glow plugs to complete the full 8 second cycle before starting. No reason to skimp on using these and they can only halp with combustion.

My old bulldozer didn't even have glow plugs and started right up in freezing weather. I always start the big engines at low idle. Single cylinder engines and 2-strokes are different though.

 

[Gittyup]

When it's warm, say above 60, I don't wait at all for the glow plugs. It actually starts better this way when warm, and smokes less. I usually let it warm up at about 1500 rpms for a few minutes before use. When it's cold out I let it warm up for at least 10 minutes.

I always, always, always, let the engine idle at minimal rpms for a minute or two before I turn it off. I was told a long time ago by a old time tractor mechanic to do this because it reduces valve wear. I do it on all my equipment, even my cars and trucks. I've never had an oil burner, and I think this really helps prevent it.

CrabJoe, yours shouldn't be smoking for a full minute.

 

[IXLR8]

I start mine at idle, small puff of black, as soon as idle settles down, 10-30 seconds depending on temp. I drive it out of the shed and what I do next depends on what I am going to do with it. If I am going to ask it to work, I let it run for a minute or two before starting, and I start gently and don't ask full power until it is fully up to temp. It warms up much faster if being used a little. If I am just going to use it as a powerful wheelbarrow.. then I just go do it. When heading 'back to the barn', I tend to run it at about 1200 rpms. Then I idle it down and put it away while in low gear. This gives it cool down time, and makes sure I don't hit the ROPS as it misses by less than an inch. If I have the chains on and they are in the wrong position.. I can hit the ROPS.. it is that close. New pole barn in the planing stages to fix that problem.

 

[crabjoe]

crabjoe, I didn't look far back to see if you already had a thread about the exhaust smoke, but mine 'smokes a ton' too for a minute if I start it at 1900+ RPM. So before shutting it down I lower the idle to 1600; when starting next time it fires up quicker and hardly any smoke at all. The JD 'dozer is the same way.

Does erratic idle mean it races and slows down by itself? That might be the TPI in my truck but I don't know (yet) what would cause it in our tractors.


It doesn't get hot here so can't say.

Before I shut down, I pull the throttle all the way back. As for erratic, when I start it, the idle jumps a few hundred rpms up and down until it settle. If I push the throttle up a bit to give it more fuel to try and settle it, it makes no difference. It's as if it can't get enough fuel until the motor heats up a bit.

BTW, if I cycle the glow plugs twice, it's just a puff of smoke and idle settles pretty quick.

 

[crabjoe]

I always, always, always, let the engine idle at minimal rpms for a minute or two before I turn it off. I was told a long time ago by a old time tractor mechanic to do this because it reduces valve wear. I do it on all my equipment, even my cars and trucks. I've never had an oil burner, and I think this really helps prevent it.

On a non-turboed engine, I don't think it makes any difference if you let it idle a bit before shut down, because cutting off fuel is cutting off fuel.

On a turbo charged motor, you want to idle it a bit to let the turbo cool, especially when the turbo's been worked hard.

Then again, maybe a bit of idle is good to allow the motor to cool a bit... I do know that with diesels, you don't want to let them idle to long because you can cause wet stacking, which is bad for the motor.

 

[Gittyup]

As I was told by the old time mechanic, if you turn it off while the valves are moving fast and hot, it causes the seals to leak prematurely, and then it starts to burn oil. It makes some sense to me. I have some engines that will sometimes backfire if turned off without letting them idle down for a while beforehand. On these, I can even hear a slight change in the pitch of the engine after slow idling for several seconds.