What Benefits Are There From The Idle Up Feature Through The Speed Control Buttons?

[Goose55]

I might never known this existed if the Service Writer hadn't activated and bumped up the RPMs while my 3500 Cummins was in line for service

Talk to me about this feature. Why was it even created?

 

[diymirage]

Bwst i know it's to keep the alternator spinning at a rate where it puts out enough amps to power high load electronics (think of hydraulic pumps)

 

[crash68]

Why was it even created?

HD truck have the option for running PTO pumps off the transmission, the elevated idle is for being able run the pump speed up and as mentioned above it can ramp up alternator output for heavy draw like winches.
The high idle can also be used to help speed up warming the engine in cold weather but the ECM will also ramp the idle up but maybe not as much as the what idle control can.

 

[Goose55]

Anyone here thinking about low idle soot being produced at low idle or is that not a concern?

 

[Docwagon1776]

Anyone here thinking about low idle soot being produced at low idle or is that not a concern?

Did you forget you had this conversation a month ago? https://www.ramforum.com/threads/ho...-to-complete-a-dpf-regeneration.220043/page-2

Unless you're running a PTO or winch or the like, you should not be using high idle.

 

[dieselscout80]

Unless you're running a PTO or winch or the like, you should not be using high idle.

I had a high idle switch on my 97 GMC diesel that I really liked.

Some other uses are warming the truck up in the winter and jump starting equipment.

I wish I could have the Ram on on my 6.4 HEMI.

 

[BossHogg]

The high idle can also be used to help speed up warming the engine in cold weather but the ECM will also ramp the idle up but maybe not as much as the what idle control can.

Additionally, you can use the exhaust brake in combination with high idle settings to increase engine load and speed up the warm-up. GM charges for the high idle feature; we get it standard with the Cummins.

 

[Goose55]

"GM charges for the high idle feature; we get it standard with the Cummins."

 

[Docwagon1776]

I had a high idle switch on my 97 GMC diesel that I really liked.

Some other uses are warming the truck up in the winter and jump starting equipment.

I wish I could have the Ram on on my 6.4 HEMI.

There are aftermarket solutions for a high idle on the 6.4L, depending on your year. AEV and Tazer OBD plug ins both allow it on older trucks, but I don't recall the cut off years. Neither will do 2025s, though.

 

[lpennock]

Unless you're running a PTO or winch or the like, you should not be using high idle.

Does help in Phoenix summer with the AC. Pulls additional air through the condenser so the AC runs a bit cooler when parked extended periods.

 

[LouM]

I can recall numerous instances of blocking the throttle to get a high fast idle. Sitting parked and working from the headlights, boosting batteries, heat or ac while parked.
Also a high idle rpm should not be a heavy soot producer, much less then driving it actually.

This is my first RAM 2500 diesel, however I have been running diesel trucks and tractors from way before emission systems started.

 

[Bighorn_Brown]

Very much like the feature available in semi trucks. I’d bump up the rpm’s to give me enough power to provide electricity, and adequate cooling/ heating while sitting inside. There were times I’d park on a Friday, and it would idle until Monday morning right before hitting the road again. Surprisingly, it used minimal fuel.

 

[magman777]

I drove semi for nearly 40 years, and we idled the trucks up whenever we left them running. The main reason we did was to keep the oil pressure up and extend the life of the engine.

 

[06 Dodge]

When I first leaned about high idle I was told it was available for 2 reason one for those who had a PTO, the other reason was to help prevent wet stacking the engine in cold winter temps, during the winter a lot of people would let the engine idle to keep heat the cab in sub zero temps, idling a diesel in cold temps can cause all kinds of problems like cylinder wash...

 

[Docwagon1776]

Also a high idle rpm should not be a heavy soot producer, much less then driving it actually.

The issue isn't amount of soot produced, but what happens to the soot in the new vehicles. It accumulates due to low exhaust temp from the light load.

 

[nlambert182]

Exactly.... even at high idle, with no load on the engine it's not going to create high enough temps to burn off the soot in the DPF.

 

[LouM]

It shouldn't be creating enough soot to even be of any consequences.

 

[nlambert182]

Immediately, no but over time it will build up if the truck isn't ran hard enough to burn it back out.

 

[lpennock]

Over time the truck will do a regen anyway so I doubt the soot load as any worse than just driving around town.

 

[Docwagon1776]

It shouldn't be creating enough soot to even be of any consequences.

The owners manual disagrees.

"The driver-controlled high idle speed feature will help increase cylinder temperatures and provide additional cab heat, however, excessive idling may still cause the exhaust aftertreatment system to not properly regenerate. Extended periods of idle time should be avoided"