How long can the duramax be left at idle speed? I have heard with other diesels it is bad to leave diesels idle for extended periods of time because the fuel will wash down the cylinder walls, unless a high idle is installed.


Hooking up trailers, running into the store, etc. my truck is left at idle for about 5 or 10 minutes max. Is that ok or should I shut it off? Will a fast-idle help or is that just used to warm the truck up faster in cold weather? Either way I plan on adding the high idle.


Any other tips/suggestions would be great. Just got the truck a few weeks ago and love it.

Personally I don't let it idle for long periods of time. Then again, I have to wonder if this is a problem with older diesel designs. Does the owner's manual mention this as a potential Dmax problem?

5-10 minutes is OK..........


I like to keep my cab cool or warm........http://www.dieselplace.com/forum/smileys/Big Smile.gif


In the winter with my truck on a Hi-IDLE of 1200 rpm I almost never shut it down at all......


Especially if it's cold out.


Thttp://www.dieselplace.com/forum/smileys/Clown.gifNY

If you have no reason to leave it idleing, like a person or pet that needs the AC or heat on then shut it off.


With the wide use of fuel injection in gas cars and trucks and electronic injection in diesels there is no reason to leave it idle, it will not help anything, and if anything do some damage like you said with the washed down walls.


Unless you just got off the highway or were pulling a big load in town and have a lot of built up heat in the engine, then just turn it off.


Only guys who idle trucks a long time are the big rig trucks at the truck stops or rest areas and thats only to be able to run the AC or heat for the cab while there usually sleeping. And even those trucks are getting away from it now that smaller seperate engines are being attached to the trucks to run the AC and heat.


So it's really up to you, if you feel comfortable with letting it idle for a couple of minutes to hook up a trailer go ahead, but if it's anything longer I personally wouldn't do it.http://www.dieselplace.com/forum/smileys/Big Smile.gif


And welcome to the forum. Lot's of knowledge here about Duramax's and GM trucks. Any specific questions, ask away.


And read up on all the past posts that you have time for, and look up the Do It Yourself section, lot's of good articles there including installing the High Idle.


Just my .02 http://www.dieselplace.com/forum/smileys/Rock On.gif Diesel Dragon http://www.dieselplace.com/forum/smileys/Cool.gif

367 seconds...max

Personally...

I rarely shut the engine off when refueling. I realize that the engine is inefficient at idle and idling for lengthy periods will have an adverse effect on fuel economy, however I do not believe that a diesel engine is any less susceptible to wear at start-up than a gasoline engine. I therefore see leaving the engine running as a type of preventative maintenance expressed as operations with forethought.
I too enjoy getting back into a cool cab after filling up in the 95°F heat.

As an aside, I noticed when I went on vacation a while back that the gasoline powered shuttle busses that run between the air port and the resort and around the resort...that many of them have anywhere from 250,000 to 350,000 miles on them. I asked about this and the driver indicated that the engines are rarely shutdown.
This philosophy, if you will, creates the market for pre-lubers

wickedsprint, "367 seconds...max"

HUH? Sarcasm?

If its going to idel for more than 5-10 minutes i will shut it off. I ussualy let her run if I am fueling unless i am going to check the oil.


I also turn the air conditioning on when I let her idel since it keeps the EGT's up a bit more. Kinda a poor mans high idel.

I leave mine idling for quick stops. I would rather not put the added load on the starter etc.


When towing, I either don't shut down while fueling or wait a couple extra minutes, just to keep fresh oil flowing through the turbo. Haven't gotten a good answer on the need for this but I think it is better to let the engine temperature equalize slowly while alive vs. the quicker cycling while off.

No one so far has answered the question, is it okay for our diesel trucks to ilde for like an hour. My dad delivers camper all around the US and he always keep his truck running all night while he sleeps in it. My dad's tuck is a Ford 7.3 that has 300,000 miles on it. It seems not to hurt his truck.

Good that you finally ask the question. All night would be extended idling where I would expect problems.... Watch your temp guage after 1/2 hour or more. Bet it is below operating temperature.

If you have no reason to leave it idleing, like a person or pet that needs the AC or heat on then shut it off.


With the wide use of fuel injection in gas cars and trucks and electronic injection in diesels there is no reason to leave it idle, it will not help anything, and if anything do some damage like you said with the washed down walls.


Unless you just got off the highway or were pulling a big load in town and have a lot of built up heat in the engine, then just turn it off.


Only guys who idle trucks a long time are the big rig trucks at the truck stops or rest areas and thats only to be able to run the AC or heat for the cab while there usually sleeping. And even those trucks are getting away from it now that smaller seperate engines are being attached to the trucks to run the AC and heat.


So it's really up to you, if you feel comfortable with letting it idle for a couple of minutes to hook up a trailer go ahead, but if it's anything longer I personally wouldn't do it.http://www.dieselplace.com/forum/smileys/Big Smile.gif


And welcome to the forum. Lot's of knowledge here about Duramax's and GM trucks. Any specific questions, ask away.


And read up on all the past posts that you have time for, and look up the Do It Yourself section, lot's of good articles there including installing the High Idle.


Just my .02 http://www.dieselplace.com/forum/smileys/Rock On.gif Diesel Dragon http://www.dieselplace.com/forum/smileys/Cool.gif





I doubt you would wash down the rings at ldle, there is very little fuel being injected into the cylinders at low speeds..

I idled my a bunch this winter, even all night once. It doesn't seem like it made any difference to me. I knew guys around my home town that would leave their trucks run 24/7 most of the winter. Gas or diesel it didn't seem to matter. I wouldn't worry about it...

Ox

Mine does alot of idling in the winter. It doesn't hit operating temperature, when its cold out. Even with the bra on. I prefer to let mine idle on the short stops. Prevents wear on the starter. However I still admit to not knowing too much.

Thanks for the replies.


So a high idle is mostly used to keep the engine at operating temp (or help get it to that at startup while cold)? I would probably never run the truck at idle for more than 15 minutes. But if I left it on for 5 mintues at normal idle (~700rpm) and the operating temp was normal (~200 deg.) it is ok?


Heck, i'll just run it like our gassers. We let them idle for a bit after towing too to let the tranny cool down.

I hope it doesn't hurt to idle for extended periods of time... I just spent 2 1/2 hours in a Chicago traffic jam!!!

Idled truck at 1200 rpm this past winter for about 3hours just to keep it warm. -15F outside ambient. Truck was nice and warm when I got back in. When racing in the colder months when temps are around freezing, you will need high idle just to keep your juice active!!http://www.dieselplace.com/forum/smileys/HiHi.gif


I see no problem with idling. Over a 1/2 hour, high idle might be better, but whatever.


Jason

I wouldn't expect cylinder wall washdown. I read once a diesel engine idles at 80:1 air fuel mix (compared to the 14:1 gas mixture).

I run heavy equipment for a living, and we let them idle all day. Sometimes, I will run 3 machines in one day, the others idle till needed, sometimes 7 hours straight. We run all Cat equipment from lots of brand new pieces to some with 15,000 hours on them. Starters are quite pricey for our high torque motors, diesel fuel is much cheaper. Idling a diesel motor for long periods of time, in my and Caterpillar’s opinion is not a problem.