Well, on my drive home yesterday I came to a light where it takes forever to change so I put the truck in park. It was pretty cold and about a minute later the high idle kicked in. IT DID NOT LOPE at all. This is not a high idle thing. It's definitely got something to do with a cold start. At least on my truck that's the case. Again, I'm not worried about it. Just trying to chime into the convo here....

 

mine will do it whenever it wants it does it on High Idle mostly auto that is, mine will try to do a little very small lope when Iset it but so what..
I also know it has NOTHING to do with voltage in the batteries thats just silly,its strickly just an Engine keeping warm thing even if your engine says its 210,,, if the OUTSIDE air is cold it will kick in thats a fact. its not just a cold start, to prove it ,,,,,30 mile trip -5 outside, came to light put in Nutral,(auto flows fluid in nutral not park) and within a few seconds it went to high idle..so not a cold start thing.

 

Again: A lope is a fast slow fast slow fast slow wobbling thing. Going from 700 rpms to 1000 rpms is not a lope. Going from 1000 rpms to 1050 rpms every second is a lope.

And I think Cummins has the engine rev up because the exhaust gets too cool.

 

Thats correct..
what I meant to say was "mine will (lope) whenever it wants" I know what the lope is, I also know how the auto High idle works, Mine also wont lope at a constant, meaning it wont be a steady lope like your example,1000 to 1050,and back, mine jumps around sometimes a short lope then a high lope or something inbetween Kinda like a v8 hemi with a 268 or 288 degree lift perfomance Cam, thats similar to how mine runs.not a steady blurp blurp blurp......
Also I dont think Mine revs up because of a cool exhaust (non egr)truck also ther is no factory exhaust monitoring by the ecu in the cummins on a 05. Oh and mine will lope even with the exhaust brake on.. err try to LOL.

 

My RPM's are rock solid when it lopes. There is no noticable RPM change that I can see. Who can we contact that can tell us exactly what this lope is? How to contact?

 

My RPMs are solid as well. The loping will continue but the tach is steady. I am not worrying about this anymore. Sounds like the consensus is that this is a normal event during cold weather. really surprised there are not any Cummins engineers or techs chiming in???

 

Another thought. This past 2 weeks here in Montana, its been between -15 and -30 below. When the truck would go into high idle at these temps, the loap was more pronounced. Today it is 30 above (heat wave) and the truck did not loap. Over the years I've noticed that the colder the temp, the more pronounced the loap. Warmer, was less loap????

 

My 06 did this for the first time yesterday, 54k miles with a fresh Baldwin 7977and about 20 degrees outside. I think it sounds cool but was concerned because I'd never heard it before. I recorded a video to post to see what everyone thought but found this post which answered my question. My truck sounds like the youtube post that Valv referenced only mine has straight piped 5" exhaust. Not worried about it anymore.

 

I say NORMAL, my 04.5 does it too on auto high idle. Truth be known I think it's using more fuel than normal to create a higher EGT when ambient air temp drops and the rough idle is a side effect. I can smell a difference in the exhaust as well as hear the "rougher" idle.

 

Mine does the same thing this year, this is the first year.

It will go into high idle when it needs to but after a minute or so it will start a slight lope almost as if it has a nice cam. If you look closely the tack will barely move, so my guess is the injectors are a little dirty, just need to run it a little harder.

But if the grid heater kicks on with the cold batteries that could be pulling voltage thus reducing the spark to the plugs, are you guys running auto lights or champion?

Sorry, I tried to resist the temptation, but I could not. HaHa

 

The lumpy idle of which you speak could be a quick engine warm up and emission control feature. Three cylinders are fired alternately with a greater fuel charge than what is needed at idle with all cylinders hitting on every rotation. 2,4,6 one rotation.1,3,5 the next crankshaft rotation. Think of twice as much fuel per injection event, but same idle speed. Emissions are also improved. The ECM knows cold is not good, so it seeks to speed the engine warm up. Alternately the truck will sense a cool down even after a drive and return to this lumpy idle, when it is very cold, until the thermostat normalizes. My friend a B series engineer since 1989 at Cummins worked on the software development but did not know when or if Dodge had implemented it. He did know it absolutley existed for 3rd gen engines as he worked on the development of it. Who knows what Dodge did. There is nothing wrong with your truck! Have u noticed it goes to high idle instantly below zero degrees F? but it is a while before the lumpy idle initiates. Just my thoughts.

 

Third Gens don't have a 3 cylinder high idle.That was ONLY a 2nd Gen program.Mine was lumpy until I installed a modified crank sensor.Its smooth no matter what the temp or start up RPM which can be 1000 if cold enough.

 

I kinda like it anyway!