O.K. I have always been told that if you are just going to run into say a store or your house for a few minutes it is better to just let your truck idle because constant starts are hard on the starter.
Now I am hearing that idling is seriously bad for your truck.
It seems that every time my wife wants to go to the grocery store The little one falls asleep in the truck and I stay in the truck with her while the wife shops.
Should I idle or shut it off....

 

Idling is a two part deal.

1) It's good to idle so that EGT's cool down to a safe level before turning off.

2) It's bad to idle for very long periods of time because you will get cylinder wall washdown and a little fuel in your oil.

I believe I read somewhere that idling over 15 minutes is excessive, so with that in mind leave it run for 5 minutes while you run into the store for some coffee or beer, but shut it off or get a high idler if you are waiting in the parking lot for the Mrs. for an extended period of time.

 

Be mindfull of the state that you are in. Check your local laws, some states and or cities state it is against the law to let a vehichle idle while you run into the store. Yo could a) get it stolen or b) get it towed and get a big ticket

 

starters are cheap compared to cylinder scoring from washdown, dirty injectors.......
i always shut it down if i have to wait more that 5 minutes

 

If the little one's asleep, do whatever you have to to keep em that way. May have to drive laps around the parking lot.

 

Personally, I wouldn't worry about it. Let it run if you want to. Shut it down if you want to. It's a machine.....it doesn't care and it doesn't have feelings.

I don't intentionally let my truck idle and idle.....but if im stopped somewhere and need A/C etc.....I keep myself comfortable and let it run.

Honestly I don't think idling hurts them. Big rigs do it all night long.

If cylinder "wash down" does exist.........I have never seen any documented proof of Cummins engine damage due to it on this board or any other source. I'd welcome somebody to prove me wrong and show me the evidence or a link to it.

 

I have done more laps around parking lots than I can count !!!

 

I am all for letting it idle if it is too hot, OR too cold. I do have a high idler, and use it if I'll be more than 10 minutes.

 

SuperGewl is correct. Certain States do have laws about leaving an unattended vehicle running. I can't imagine it being an expensive one as much as it would be an aggravation.

 

There was a long post here about 6 months ago on the subject.

I believe the concern with these new motors is due to the injectors. With mechanical injection, like big rigs, they can idle all night. I think the new injectors run into problems when squirting little fuel for long periods.... but that’s only my recollection.

 

I work out of my truck so it idles all day long. I was told as long as your engine temp stays up so that your fuel burns, your allright. I use the cruise control to idle my truck up to 1100 RPM. I know guys that do the same type of work that have more idle time than driving time on thier trucks and I havent heard of anyone having trouble. I think that it is hard on your tranny because it doesnt lubricate unless you have work done or replace your valve body.

 

If that is a factory function his problem is solved. Idling is at 700-800 RPM, but if you guys have a high idle function that is the solution to your problem. You can let it run nonstop if you get the RPM up!

 

After I read your post i went out to my truck and tried to set the cruise controll on my truck at 1100 rpm. It won't set I tried diferant things to see if it would set with the door closed and my seat belt on and even in gear(automatic). No luck, is there someting else that I need to do to set the cruise higher while I'm parked?

 

Big rigs don't "idle" all night...they run at 850-1100RPM, depending on the brand!

The problem with idling you're Cummins, is not so much wash down (at least not with stock injectors), but your 24v can get "cold" EGT's, and begin to build up carbon on the valves. If enough builds up, it can bend pushrods. Not a common failure, but not unheard of either!!

Bottom line, you can leave it idle for a few minutes, but beyond that, idle it up...at least 11-1200RPM! That keeps everything buning right where it should be

Chris

Besides, don't you CR guys have that Cruise Control high idler??? Cheaters...I have to use a stick

 

the dealer has to enable it. It is a TSB. it's for the complaint of rough idle and slow warm up. It is a nice option, i use it all the time