Facts about diesel ideling

garyp4951 wrote:

DutchmenSport wrote:

allen8106 wrote:

DutchmenSport wrote:
...

I'm pretty sure theres no requirement to wait for it to drop to low idle before you drive.

Probably not, but if taking off on fast idle, backing out of the garage, or whatever, have to ride the brakes harder. Usually, it drops from fast to slow quickly, like ... 60 seconds. By the time I get my seat belt buckled and radio set, it's usually dropped low.

The important thing with idle, and my dad always said this (with gasoline engines), is to run the engine just long enough the oil circulates to the top of the engine, as it drains down when the engine is shut off. And that takes only a couple seconds to happen. Basically, been following his advise ever since. The only reason to run a longer idle is to warm up the passenger area or defrost windows in my opinion.

My high idle comes down as soon as I touch the brake pedal.

Same here. I wonder if they are setting it manually. One minute to come off high idle after hitting the brake or putting it in gear is an eternity.

Edit. I think I misread what he was doing. I think he meant it goes directly to high idle on a cold start and comes off it within a minute. It would then go back to high idle if left to just sit there I assume.

DutchmenSport wrote:

allen8106 wrote:

DutchmenSport wrote:
...

I'm pretty sure theres no requirement to wait for it to drop to low idle before you drive.

Probably not, but if taking off on fast idle, backing out of the garage, or whatever, have to ride the brakes harder. Usually, it drops from fast to slow quickly, like ... 60 seconds. By the time I get my seat belt buckled and radio set, it's usually dropped low.

The important thing with idle, and my dad always said this (with gasoline engines), is to run the engine just long enough the oil circulates to the top of the engine, as it drains down when the engine is shut off. And that takes only a couple seconds to happen. Basically, been following his advise ever since. The only reason to run a longer idle is to warm up the passenger area or defrost windows in my opinion.

My high idle comes down as soon as I touch the brake pedal.

its usually the "hey look at me guys" that do it.

I think that may be true.

That link is meant for commercial class8 trucks. idling in the morning to warm up is acceptable. idling for anything more than 15 minutes is pointless as a diesel needs a load to get to operating temp. and yes trucks don`t need to be idled all day long, its usually the "hey look at me guys" that do it.

GordonThree wrote:
If all these facts are so well known, why do so many leave their diesel pickup idle, for example, the entire time they're setting up or breaking camp, half an hour, maybe more? When are all diesel going to come with an automatic shutdown on idle?

A guy at work had a 2003 Ram 3500 Cummins that he let idle very often, ie. run into the grocery store for 15 minutes on a hot or cold day, etc, and he had no issues with it. He traded it last year for a new 2016 Ram 2500 Cummins and was upset that he kept triggering his check engine light, so he took it to the dealer. They told him to quit letting it idle. Check engine light problem then went away.

Some of you are forgetting about the old 2cycle detroits with wet? sleeved cylinders. If you did not warm them up before a hard start, the cylinder would come out! THAT is and only HAS been the reason from what I have heard to truly warm up a diesel.
For some, yes, overnight sleeping in a cab. But as noted, one needs to keep the motor at a higher then normal low idle.
I've never generally speaking let any of my now about 6 different diesels to idle at start up for long. My equipment will idle per say for 5-10 minutes. but that is so the hydraulic oil etc warms up. The motor, start up and go generally speaking.

Trains, some boats etc, they leave the motors when stopped, so the units have AC power, due to many being a diesel run generator. WHile the diesel needs to run, the generator runs the AC and DC with in the unit. So shutting them down is not always in the best interest of ALL involved.

Marty

Cummins12V98 wrote:
Looks good to me!

Now that's a nice lookin truck.

kep5niner wrote:
The credo is to not shut down once it's started - because you might not get it started again.

And I thought you were describing my former employer's fleet maintenance division. :B

Gearitis wrote:
I have a Scangauge II that I monitor the EGT (Exhaust Gas Temperatures) especially the 1st sensor. I will idle the engine on my 6.7 diesel until that temp gets under 400 degrees then I feel better about shutdown. Reason, Motor oil can and will burn at 400 degrees or so. Allowing that turbo to cool and allowing the oil to keep moving rather than stop pumping on 1000 degree bearings and bushings until most everything is under that threshold makes me more at ease. Just an ole farmer here talking that had nothing but diesel engines grown up.

Motor oil shouldn't have any trouble handling 400°F. Heck, the canola oil I used to use in our Fry-Daddy would handle 400°F.

rhagfo wrote:

leggy wrote:
One thing I always think about when this subject comes up, what about traffic delays? Are you supposed to shut down if sitting in a traffic jam? By some people's comments, they would shut down at a long red light!

Auto shut down is coming your way!
Just had a rental car in Ireland that had this "feature"!

You didn't need to travel so far for stop/start. I think almost every Chrysler now has stop/start available. At least in the 1/2 ton and lower categories.