The Truth about Idling
 

On a STOCK truck:
I have heard many rumors about Idling. For example, some people say DO NOT let truck idle over a few minutes. Others say it will not hurt it.

I realize the answer to these points is dependant on how you drive the truck.

If I'm stuck on the interstate due to a traffic accident and it is 100 degrees, am I supposed to tell my wife and kids:" Well Boys! they say we CANNOT let the truck idle, we must kill the truck and sit here and sweat like hogs until traffic clears!" My wife then says "You mean to tell me we spend $40,000 on a truck and we have to set here and sweat! This is crazy?

Therefore, how much idling is Too Much idling? Anybody know Cummins/Dodge official stance on the topic of idling??

I idle my trucks when I want and for how long I want. Nobody is going to tell me different. I idled my 04.5 to death even in below zero weather. Never hurt it never got less than an excellent oil sample report from Blackstone. On this new one if I idle it I simply just bump the idle speed to 1100 which is cruise on and then the set button. If this one craps out because of idling then I guess that's why I have warranty and I'll look for something different for the next truck. It just isn't realistic to not idle these trucks for your scenario as well as the heater when it's -30 F here in the Winter either.

Dodge wouldn't sell a truck that you couldn't idle would they? Our 2011's idle fine.............now.:cool:

When I was stock and the 6.7L engine first appeared this was a concern also of mine. I did extensive research on this and read what Cummins had posted in their newsletter around 08. A lot of users were complaining of excessive fuel build up in the oil and soot build up in the engine when idling for extend periods of time.

Will Cummins stated (this is from my memory) to use the High Idle feature for extended periods of time, this means the RPM's should be over 1100 RPM's on theTac. The reason they stated to use the High Idle feature is to allow the engine to run more efficiently and to allow the DPF to Regen if needed due to excessive idling. This is why the feature is on the 07.5MY trucks and up that are built with the 6.7L engine, to allow the engine to be idled for extended periods of time.

Remember if you are in California and in a traffic jam you may be ticketed for excessive idling by the police. It is one of their crazy laws.

I use the High Idle feature all of the time especially in the winter months to warm the engine up.

Jim W.

Base engine idling for extended periods of time does lots of damage to an engine. What happens is at base idle the fuel is not completely atomized, therefore it leave fuel residue on the cylinder walls where oil should be and in turn mixes with and dilutes the engine oil. This is called "wet stacking" and it will prematurely wipe out an engine. There are other concerns also with extended base engine idling, hot/cold spots in the block from inadequate coolant flow, etc. These have been concern for decades, however with the advent of all the emission tiers the problem has become much more prevalent due to major increases of soot loading from egr and low cylinder temps. If your going to sit and idle for anything more than a 2-3 minutes you should engage the high idle. It will help atomize most of the fuel, keep temps more uniform and overall reduce the affects of extended idling.

Sitting in a traffic jam and idling is not an issue unless your going to be sitting there for an hour not moving, then just bump up the idle.

FYI, the Cummins ECM store all engine on/idle time.

Turn on the exhaust brake, bring the idle to 1100RPM, and forget about it.

Although, if the DPF is still there, the more you idle, the more it will fill up and need to burn off.

Run her hard, she'll love you long time:D
Chris

Don't use the curise high idle function for very long if you need to idle your truck. There are actually 3 Idle stages in the truck, 900 (soot reduction), 1000 (Cold intake temp), and 1100 (cruise activated)
The new ECM programming has a function the will bump the idle to 900 rpm and go into a soot reduction mode, it's kind of like a regen at idle. if you use the cruise to bump the idle to 1100 it will never go into this soot reduction mode, than youll get a catalyst full message, therefor requiring a trip down the highway requiring a regen.
I told my brother this who idles his truck for 8-10 hrs a day and he rairly has a catalyst full message. He says letting the truck go to 900 rpm on its own helps alot, from our experiance using the cruise plugs up the DPF ALOT quicker, the truck will go to 900 in the summer and of course more frequant during the winter

Good point Caper11. I remember when that ECM update came out, I think before the J35, that engaged that soot reduction mode.