High Idle

[mbarber84]

No you are not. If it’s not prolonged it’s fine if it’s idling for a while just put it in high idle. No need to wear out the starter switching out trailers

If all he’s doing is stopping for a minute to switch out a trailer, I agree. Just let it run for the minute or two it takes to make the swap. But it sounds to me, based on what he’s experiencing with the idle ups, he’s doing a lot of low rpm work for extended periods of time. That kind of scenario lends itself to socking the DPF with soot and no opportunity for the truck to get the EGT’s up sufficiently to burn it out. Given the choice between having incessant DPF related issues or replacing a starter, I think I’d pick the starter. In either scenario (shutting down or idling) the real solution here is to make it a point to monitor the DPF gauge regularly and get the truck out on to the interstate for some high rpm / high load driving to clean it out.

 

[H3LZSN1P3R]

If all he’s doing is stopping for a minute to switch out a trailer, I agree. Just let it run for the minute or two it takes to make the swap. But it sounds to me, based on what he’s experiencing with the idle ups, he’s doing a lot of low rpm work for extended periods of time. That kind of scenario lends itself to socking the DPF with soot and no opportunity for the truck to get the EGT’s up sufficiently to burn it out. Given the choice between having incessant DPF related issues or replacing a starter, I think I’d pick the starter. In either scenario (shutting down or idling) the real solution here is to make it a point to monitor the DPF gauge regularly and get the truck out on to the interstate for some high rpm / high load driving to clean it out.

In the past with the older trucks i would agree with you but my 19 i have about 1/3rd idle hrs compared to drive hrs and a lot of my drive hrs are low speed low load plowing hrs. I did not have any issues with DPF my gauge hardly ever showed soot % maybe 3 times in the 53,000km the DPF was installed. I removed the dpf only because i removed the DEF system due to constant freeze ups i had no issues with the DPF though. Perhaps i am just lucky though

 

[oscar]

No you are not. If its not prolonged its fine if its idling for a while just put it in high idle. No need to wear out the starter switching out trailers

I switch out about 75 trailers in a week....... Here's my "herd". It's used to store the stuff for an event. I haul them a mile over a hill to our ops center, do maintenance on them and then move them to where they need to be. Some right away, some sit a few days..... At the back end it all reverses. The bigger ones are well into the teens and mine is the only truck that can get them over the hill. That's my camper on the right in the second pic. A few days after that was shot, that whole hill was covered in cars.......

As far as the DPF discussion, I arrive at this event after 300+ highway miles, so with a squeaky clean DPF. During I do a few "town runs" of just under 20 miles. It may well get a regen in there if needed. Now that I know where we're thinking, I'll keep a better eye on the gauge.

 

[MontanaUSAF]

I've had problems with my DPF on 2022 2500, builds up to 50% once a week and have to run on highway for 30-40 miles to clean out, our Ram service manager told me anything 20 mph or under is considered idle hours..

 

[AH64ID]

Ram service manager told me anything 20 mph or under is considered idle hours..

20mph isn’t quite accurate in my experience. I put 34 hours on the pickup in October with an average speed of 9.7 mph and it was mostly drive hours. I would go days without getting above 15 mph, lots of drive hours and very few idle hours.

I do think that it’s around 3 mph thou, which is the speed for low range engagement/disengagement as well as air suspension adjustments.

 

[Will_T]

I put 34 hours on the pickup in October with an average speed of 9.7 mph and it was mostly drive hours. I would go days without getting above 15 mph, lots of drive hours and very few idle hours.

Just so weird, I don't know how anyone can figure this out. My driving is completely opposite from yours. Other than hooking and unhooking the TT, (usually fast but once in a rare while 10 or 15 minutes getting into a tight camping spot), pretty much all of my miles are towing the TT on main roads and highway. Typically hook up and drive towing 1 or 2 hours to 4 or 5 hours. Almost all of those miles are probably between 40 and 65 mph. Yet my EVIC today shows that idle hours are 32.4% of the total hours.

 

[AH64ID]

Interesting. I’m sitting at 11.9%. October is my highest idle time of the year.

Sold my ‘18 with just under 8.1% idle hours. The ‘22 seems to count idle hours faster, but I’m only at 5500 miles.

 

[CFE]

Bumping an old thread to re-energize the high idle conversation.

I recently learned the "high idle - cruise control in park" trick on this site after reading on here about how normal idle for these trucks is terrible for pro-longed periods. That being said - I'm going to be idling for more than 3+ minutes, i'm assuming it's safe to let the truck "high idle" at the 900/1k RPM the cruise control bumps it too?

Just trying to make sure I maximize the 6.7's lifespan.

 

[mbarber84]

Bumping an old thread to re-energize the high idle conversation.

I recently learned the "high idle - cruise control in park" trick on this site after reading on here about how normal idle for these trucks is terrible for pro-longed periods. That being said - I'm going to be idling for more than 3+ minutes, i'm assuming it's safe to let the truck "high idle" at the 900/1k RPM the cruise control bumps it too?

Just trying to make sure I maximize the 6.7's lifespan.

Yes that’s actually a good practice. Better to have higher oil pressure and will keep the cylinder temps up for better fuel combustion in the cylinders. Reduces the amount of unburnt fuel sent downstream to the DPF at regular idle.

The truck will automatically do this anyway if it detects about 2 hours worth of prolonged idle time. It’s called hydrocarbon desorption mode.

 

[AH64ID]

The truck will automatically do this anyway if it detects about 2 hours worth of prolonged idle time. It’s called hydrocarbon desorption mode.

If anyone wants to read a little about it, the owners manual calls it Intervention Regeneration Strategy.

 

[CFE]

Appreciate the quick response and the "IRS" note to read up on in the manual.

 

[mbarber84]

If anyone wants to read a little about it, the owners manual calls it Intervention Regeneration Strategy.

Yep. There’s a few instances in the manual were language doesn’t match what you see on the truck itself, or what’s referred to in technical documents.