Leave it run or turn it off?

[skeets]

Ever since I was a kid I was told that once you start a diesel its best to let it run, that turning it on and off is hard on the motor and starter and stuff. I always let it run like when Im loading a trailer of wood and the OL says it shouldnt be seting and idleing. So whats the right way or do it matter???

[Eric McCarthy]

I let mine sit and idle if I happen to hop off and take care of a few little tasks, alot of times I turn mine off just to have a few minutes of peace and quiet. I doesn't hurt a diesel to sit and idle for hours on end, thats one of the things they designed them to do. I've been a truck driver for 9 years and let my big rig idle often.

[next2dixie]

Excessive idling can actually damage your engine components, including cylinders, piston rings, and crankshaft bearings. A diesel engine creates combustion of the injected fuel by the heat of compression. An idling engine is not operating at its peak temperature which means that all the fuel is not completely combusted when injected. This leaves fuel residue that can collect on cylinder walls where they can contaminate and cause fuel oil dilution of the lube oil, decreasing it's viscosity. It's a good idea to add diesel fuel cold-weather treatment or an anti-gel additive to ensure that you maintain the low temperature flow characteristics of the fuel. Ensure your glow plugs are working properly and install a block heater for good cold weather starts.

My background..... Retired USN Chief Engineman ..shipboard diesel main propulsion, ....civilian job, fleet manager

[kuboman]

Excessive idling can actually damage your engine components, including cylinders, piston rings, and crankshaft bearings. A diesel engine creates combustion of the injected fuel by the heat of compression. An idling engine is not operating at its peak temperature which means that all the fuel is not completely combusted when injected. This leaves fuel residue that can collect on cylinder walls where they can contaminate and cause fuel oil dilution of the lube oil, decreasing it's viscosity. It's a good idea to add diesel fuel cold-weather treatment or an anti-gel additive to ensure that you maintain the low temperature flow characteristics of the fuel. Ensure your glow plugs are working properly and install a block heater for good cold weather starts.

My background..... Retired USN Chief Engineman ..shipboard diesel main propulsion, ....civilian job, fleet manager

I second that. Letting a diesel idle for hours is very hard on it plus it wastes a lot of fuel. Sometimes it is necessary but to do it just because it is 'cool', well plan on overhauling your engine early.

[Service Dept Vic]

Turn off your tractor, turn off your Powerstroke, turn off your Cummins, turn off your Duramax!

[gmtinker]

New diesel pickups actually have a diesel particulate filter that will plug up with soot if you idle them too much - we've seen LOTS of them at the shop over the last little while, as the auto/truck manufacturers have to deal with ever-increasing emissions control standards. It's only a matter of time before construction/ag equipment will have to comply, but hopefully the technology will be more developed by that point (and thankfully I already own my tractor I'm keeping until they wheel me into a nursing home, kicking and screaming . . .:D)

As for my habits, even though my little squirt of a Kubota is very economical, if I'm off it for more than a couple minutes I shut it down. No sense in wasting fuel, contaminating my oil, and possibly not effectively charging batteries (low alternator rotational speed).

[Eric McCarthy]

Well I stand corrected then! I've never had any major issues arise form a diesel sitting and idling long periods of time. I was driving a big rig up until last June and I pretty much had it running all day long about 8 to 10 hours, the in house shop mechanic took oil and fuel samples every so often and sent them off to Caterpillar for routine maintenance check and never heard back any bad results. The truck had a Cat diesel in it and for warranty purposes Cat wanted oil and fuel samples from time to time. Learn something new everyday!

[skeets]

I hate it when she's right:mad:

[Captjack]

you can let them idle but you need to have the idle bumped up a little. The engine needs to be warm enough to burn all the fuel or you will "wash" a cylinder.
If you notice most new diesels will idle up to about 1200 rpm's if they are left to sit.
Just my .02

[Eric McCarthy]

That clears it up alot better for me! Thanks Capt.