Idling vs shutdown and restart

[Justasquid]

I let mine idle quite a bit. Just yesterday doing spring clean up, I would move the tractor where I needed it, use the chainsaw or rake to make the pile of limbs and leaves, then pile them into the loader and move to the next area. I probably let it idle about 5-10 minutes between movements. But I only moved it about 30 feet at a time. If I didn’t let it idle, I would have started it about 20 times in a short period of time. My tractor is Pre-DPF though. If it was DPF, I might be more inclined to shut it down more often or maybe make bigger piles ahead of time.
Having said that, I let my duramax idle a lot too and it’s DPF. Maybe I just like the sound of diesels.

 

[Magicman]

A Google search will find many topics on turbo Diesel engine shutdown: shutting down a turbo diesel engine

Engine shutdown with non-turbos should not have any issues.

 

[foobert]

if it makes much difference with a thermosiphon system -- no water pump.

What vintage doesn’t have a water pump? I thought that went away >100 years ago?

 

[D2Cat]

No Wet Stacking on these machines, that goes way back to the 2 Stroke days..... I do remember them, I think>

Wet stacking was most often cause by worn rings, and then the idling would blow slobbers out the exhaust. Not necessarily 2 stroke engines.

 

[torch]

What vintage doesn’t have a water pump? I thought that went away >100 years ago?

My 1994 B7100 for one. It's not that uncommon.

 

[foobert]

My 1994 B7100 for one. It's not that uncommon.

Huh. I had no idea. I suppose that’s a testament to how low-stressed (thermodynamically) a small displacement, naturally aspirated diesel can be.

 

[NCL4701]

What I mean by closed loop is that the computer controls the amount of fuel based on readings from the exhaust O2 sensor.

It’s my understanding that the common rail engines are closed loop. Don’t know about any others.

 

[torch]

AFAIK diesel engines do not have O2 sensors. There is no throttle, air flow is wide open all the time. O2 sensors are used in gasoline engines to balance the mixture on the fly, as the air flow is varied by the throttle.

There are some "closed loop" diesel engine management systems around, but they are using other factors such as engine load for the feedback loop and strategies like pilot injection pulses rather than mixture control.

 

[torch]

AFAIK diesel engines do not have O2 sensors. There is no throttle, air flow is wide open all the time.

And I was wrong. Apparently some of the new high-pressure common rail systems do in fact have both a throttle and an O2 sensor. It's a wide-band sensor, rather than the narrow band used in most cars, but it is an O2 sensor.

 

[Buckshot1600]

Great question. I will usually keep running for anything less the 1/2 hour. I believe most engine wear happens during start up, especially in colder weather. Also I try to let the engine idle for a minute or two before shutting down. No turbo on my L3901 so no high speed bearings to worry about. Thank you for your time.

 

[PaulL]

I believe most engine wear happens during start up, especially in colder weather.

I think this is true, but I think it means start of day. Basically you get wear before the oil starts to flow around the engine, which is a function of heat and time. Stopping the engine when warm, and starting again in ten minutes, I believe wouldn't create extra wear, as the oil is warm and already distributed around the engine.

 

[In Utopia]

What vintage doesn’t have a water pump? I thought that went away >100 years ago?

None on my L175

 

[Freeheeler]

I think this is true, but I think it means start of day. Basically you get wear before the oil starts to flow around the engine, which is a function of heat and time. Stopping the engine when warm, and starting again in ten minutes, I believe wouldn't create extra wear, as the oil is warm and already distributed around the engine.

This, as well as I use SR3 additive which gets rid of stiction as well as minimizes any start up wear and tear.
If I hop off the seat for more than one minute, I shut her down. If I have to replace the starter in 20 years, I'm ok with that. The fuel savings, less noise, and less emissions are worth it I think. I don't live in a climate where I need to keep heat in the engine and I don't have a cab to keep cool. I keep a battery tender on her so frequent starts aren't problematic.

 

[nbryan]

If I'm working on the PTO I shut down every time.

^^^^^^^
Do this, everybody!