Unrealistic 5-minute idle "rule"

[Wolfy]

In several threads here and on other forums, where the subject is "break-in" of new diesel engines, it is (repeatedly) stressed that the engine should NOT be allowed to idle for more than 5 minutes.



What harm would result, I have not seen addressed(?).



But, in the real world, this seems a somewhat unreasonable request.



The kid at the dealership who is jockeying trucks around the lot, the transport guy who is loading rigs on his trailer, the sales person yaking to prospective customers, showing how "quiet" the new engines are before/after a test/demo drive, ... all are very likely to exceed this rule FOR you, aside from your own care re. the matter (as in you, the new owner who is finishing his cup of coffee in the warm house, while the rig "warms-up" outside in the cold).



How realistic is this idea, and what damage can result from non-observance?



Comments?

 

[Bob4x4]

Carbon build up is one issue to be concerned with. Thast is why we have the ability toturn on the hi idle. Realisticly D/C should have it enabled before delivery.

 

[Wolfy]

Carbon build up is one issue to be concerned with. Thast is why we have the ability toturn on the hi idle. Realisticly D/C should have it enabled before delivery.

Where is "high idle"?



How is it "turned on"/adjusted?



Thanks!

 

[jelag]

Well in some states letting your diesel idle when you walk to the rest room in a rest stop is now a fine... ... I carry the locking fob in my pocket and let the truck run in the summer for the AC and in the winter when its 5*f for the heat... My trucks often start at 5 in the morning and get turned off at 6 or 7 at night...

I've noticed that in CA it seems to be getting to the point where the drivers are listening..... one guy mentioned that in that rest area last trip a cop was watching and writing the tickets..... 155 or something like that... .

I've now seen the same signs in other rest areas in other states..... I do let mine idle but only after a complete warm up... but at 5*F you can hear the high idle after 5 minutes in the rest room..... and the temp gauge is back at 140 when you climb back in the cab... .

Just my thoughts here... . oh BTW, at some stops in the desert I've let it idle for 45-60 minutes while loading and unloading at 110*F... . other wise the cab is too hot to jump back in to... .

 

[Bob4x4]

Where is "high idle"?



How is it "turned on"/adjusted?



Thanks!

On the 04-07's the dealer can enable the hi idle feature. The hi idle is controlled by the cruise switches after it has been enabled.

The Smarty comes with the hi idle enabled if you go that route.



Bob

 

[cojhl2]

In several threads here and on other forums, where the subject is "break-in" of new diesel engines, it is (repeatedly) stressed that the engine should NOT be allowed to idle for more than 5 minutes.



What harm would result, I have not seen addressed(?).



But, in the real world, this seems a somewhat unreasonable request.



The kid at the dealership who is jockeying trucks around the lot, the transport guy who is loading rigs on his trailer, the sales person yaking to prospective customers, showing how "quiet" the new engines are before/after a test/demo drive, ... all are very likely to exceed this rule FOR you, aside from your own care re. the matter (as in you, the new owner who is finishing his cup of coffee in the warm house, while the rig "warms-up" outside in the cold).



How realistic is this idea, and what damage can result from non-observance?



Comments?

As I understood the rule, it is because of fuel waste and EPA.



I've seen diesels idle for days when it is too cold to turn them off.



As an example I had a neighbor in IA who was an OTR. When he came home for a weekend in the sinter, or Christmas for that matter for a week, and it was extremely cold his engine was never shut down. Twice a day he would go out and take it up to 2000 for a few minutes to blow the soot out.



Also when I had my Isuzu it idled all day while parked outside. Friend of mine had a Rabbit did the same thing.



You just gotta keep the rediator covered so the only heat loss is thru the exhaust. The trick is not let the engine cylinders get too cold.

 

[Vaughn MacKenzie]

In several threads here and on other forums, where the subject is "break-in" of new diesel engines, it is (repeatedly) stressed that the engine should NOT be allowed to idle for more than 5 minutes.

What harm would result, I have not seen addressed(?).

The 5-minute rule has nothing to do with ambient temperature, cylinder washdown, environmental laws, etc. etc. It follows the same reasoning as not using your cruise control or driving at steady highway speeds for the first few hundred miles.

The ideal break-in process involves varying engine RPM and working the engine to establish final finish for optimum engine sealing. I believe varying RPM changes internal dynamic forces so that the internal parts wear on each other slightly differently throughout the RPM range, so if you stay at one RPM wear-in isn't as even. This probably sounds like far-fetched theory but the 5-minute limit on idling most likely goes along with this philosophy.

I broke my two new CTDs in by not allowing more than a few seconds of idling at a time during the first 100-200 miles, and I made an effort to continually run RPM up and down (avoid highway driving, NO cruise control). When I stopped at traffic lights I revved up and down between 1000-2000 RPM the entire time I waited.

Vaughn

 

[jcarey]

The Smarty comes with the hi idle enabled if you go that route.





Hey Bob, are you letting any cats out of the bag... I hope, I hope Oo.

 

[SKing]

C/R injectors are not supposed to idle for long term at anytime. They get damaged at long idile regardless of millage. Idle kills injectors now.

 

[BHaden]

C/R injectors are not supposed to idle for long term at anytime. They get damaged at long idile regardless of millage. Idle kills injectors now.

And this would be because of... ..... ???

 

[Bob4x4]

And this would be because of... ..... ???

One theory is low heat will build up carbon much quicker.



Bob

 

[SKing]

Dont Quite understand but it has something to do with the actuator and control valve in the injector being under so much preasure at idol. The bad side of this is worn injector tip. Why I dont know and Bosch wont explain. From what I understand this is the reason why replacing a tip on a injector will not fix it if the control valve is damaged or the actuator is also bad. It will work but will not atomize the fuel correctly. This would damage the piston or ring from what I have heard from techs. After replacing 2 sets of injectors on 3 of my work trucks I no longer let the guys idol there trucks on job sites and have had no problems since.

 

[JHardwick]

The ideal break-in process involves varying engine RPM and working the engine to establish final finish for optimum engine sealing. I believe varying RPM changes internal dynamic forces so that the internal parts wear on each other slightly differently throughout the RPM range, so if you stay at one RPM wear-in isn't as even. This probably sounds like far-fetched theory but the 5-minute limit on idling most likely goes along with this philosophy.



Vaughn

My engine builder told me the same thing about my sprint engines when I raced. But his reasoning was due to the "splash oiling" that oils different components at different RPM, mainly the camshaft. Is the Cummins camshaft splash oiled?

 

[2broke2smoke]

jeeze guys ...



you guys worry way too much ...



a good freind owns a surveying business and has owned 3 first gens ... 1 second gen and is now running 3 3rd gens ...



they have all idled for hours at a time ...



my wife is a home health nurse and when she sees a patient in hot/cold weather she will leave the truck running ...



local oil and gas companies do the same thing as well ... get up on location in the middle of nowhere, hop out for a while ... a local companies mechanic told me that all dodge autos are junk they always "burn up" ... i told him to have the well tenders keep them in neutral when sitting and not park because the fluid would circulate ... he said he would tell them ... would led me to believe that they must all be idled a great deal ... he didn't mention injectors, just trannies ...



if cummins can't build a motor that can idle then i'll save 5k the next time and buy a hemi

 

[DZink24]

Take away the pi** poor paint quality, tissue paper thin sheet metal, and about 5,000 pounds of other components, what do you have?



A diesel generator.



Bump that idle to about 1,000 RPM, (or heck, 3,000 for that matter) and don't look back. Keep the fuel tank full, and shut 'er down evey 250 hrs for an oil change, she'll run forever.



There are 3 reasons that I shut my truck off, in no particular order:

Theft, noise pollution, wasted fuel.



Notice engine damage is not one of them.

 

[JHardwick]

There are 3 reasons that I shut my truck off, in no particular order:

Theft, noise pollution, wasted fuel.



Notice engine damage is not one of them.

My truck has ran as many as 10 days straight when I'm on the road. I idle my engine 5-7 hours at a time while I sleep (A/C in summer, heat in winter)... ... ... ..... but, I think this thread was geared toward the break-in period and idle time.



*On edit: I guess I should note that I have close to 270,000 miles on my truck and have never pulled an injector.

 

[jcarey]

Good info, JHardwick. I'm sure many other OTRs do likewise.



We don't tow, just trips to Home Depot, camping, and the like. We had to start putting some Redline in to clear up some carbon buildup on the injectors (smoky startup). No problem now.



What I'm thinking is that the problem may be more a lack of sufficient load to blow out any accumulating carbon in the injectors/tips, as opposed to any detrimental effects of idling (after Cummins recommended breakin, of course, and with the high idle feature enable to keep engine temps in the proper range).



Jim

 

[JHardwick]

We don't tow, just trips to Home Depot, camping, and the like. We had to start putting some Redline in to clear up some carbon buildup on the injectors (smoky startup). No problem now.



Jim

I guess I should have mentioned that I use Howes Meaner Power Kleaner fairly religiously.

 

[CBrabec]

On the 04-07's the dealer can enable the hi idle feature. The hi idle is controlled by the cruise switches after it has been enabled.

The Smarty comes with the hi idle enabled if you go that route.



Bob

I have an '03 and my high idle kicks on during the winter when it gets below 20* after being started for a minute or so. My question is, do I have the ability to turn it up with my cruise control switches like the '04 and newer?



Chris

 

[Bob4x4]

I have an '03 and my high idle kicks on during the winter when it gets below 20* after being started for a minute or so. My question is, do I have the ability to turn it up with my cruise control switches like the '04 and newer?



Chris

Nope... ... ... That is completely different. Sorry



Bob