How much do most of you guys let your trucks idle? I guess I'm guilty? of being used to heavy equipment and older diesels that may idle for hours at a time.


I've been doing some reading, however, and I've found that most feel that too much idling is bad for an engine. I understand fuel washing and related worries, but I've always figured that a warm engine was better than a cold one, especially in Montana where it gets really cold.


Question is: If I high idle a Duramax for extended periods of time, am I going to sacrifice anything? Is idling bad for a diesel?


For example, when I have to run errands around town, I plan to either be driving or letting it high idle instead of making about 10 startups.

I've always done like you, idle it for short stops rather than shut it off. Did it for years with my 6.5 with no problems. Same for my Powerjoke (although I didn't have that POS long enough to tell if it would cause problems or not). Lot of people say not to, but I really don't think it will hurt anything, as long as its not done to excess. I figure if its longer than 10-15 min, I shut er down. BTW, where in MT are you?

Wow, it's a small world out there! I'm in Twin Bridges. Do you high idle yours?

I let mine idle over the weekend for about an hour while we went into a restaurant to eat, leaving the dog in the truck. Does anyone think this is too long?

The Ford guys would install a manually controlled high idle setup. That way they could be sure to keep engine temps high enough to prevent problems. I'm sure that would be the "right" way to do it. If I was going to be regularly leaving it idle for an hour or more at a time, I would want to keep the temps up. For shorter times, I'm not going to worry about it too much. I'd quantify my position on this by saying that my diesel pickups have never been used primarily for running around town. I live a ways out in the sticks, so even a grocery run or something (20 miles at highway speed) gets it good and warmed up. If you were running 2 miles to the store, letting it sit there and idle for an hour and then going 2 miles home, probably would be better to shut it off. Better yet, drive the wife's car for that chore!

I do.

I idle alot....


I never shut it off on long trips...

I've never gone 15 minutes, but 5-10 yes.


Anyways I understand replacing a starter on a diesel can be pretty expensive.

Seems like I read somewhere that the EGR system on the new LLY engine comes into play mainly when the engine is at idle, recirculating exhaust and soot into the intake.

If that is the case, then would excess idling be even more harmful for a LLY Duramax?

i idle everywhere i go....prob 30% of my fuel per tank is idlin

I run mine like a gasser because it runs more like a gasser. Later! Frank http://www.dieselplace.com/forum/smileys/Approve.gif

Mine idles about 30 minutes a day (weekdays).

i idle everywhere i go....prob 30% of my fuel per tank is idlin


Wow...that seems like a lot fuel that is not doing any work. I run mine as Frank does...similar to a gasser. For those doing all the idling, what do you see as advantages?

I idle,a fair bit. In the winter... to try and get the engine up to some sort of temperature. Always understood it was bad for a engine not to get up to temp. Idle alot just after start up, to let cold (thick) oil circulate. In the summer, I idle for cooling of turbo (oil for bearings) I just started this, though.

When I am boondocking with the RV, I will idle 30 mins to 2 hrs to charge the RV batteries.