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Auto High Idle?


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I started my 05 this morning and went back in the house to let it warm up some. I can hear it when the grids kick in and out, anyway after the grids where done it went to high idle all on it's own. Is this stock feature? So I get in truck and give accelator a tap like you would a carborator gas eng and it idles down so then I back out and set in the drive and it starts high idle again. Anyway I drive about 60 miles to pick up a load of pipe and while I am being loaded it goes into high idle again. The nose is pointed to the north and it's cold about 32 and I had been setting about 10-15 min. When I got back to truck it had idled back down.I am still suspicious that this truck my have a programmer. Is all what I am experincing normal (stock)

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Perfectly normal. ~32° and lower it will go to 1,000 rpms after 2 minutes; ~15° and lower it goes to 1,000 as soon as you start it. Then if the ambient is lower than 32° and your coolant is below 180° it will do it again after 2 minutes of stationary time. You don't want to interrupt this, it's a feature that helps the motor stay warm to prevent cylinder washing. Really you shouldn't be idling your truck before it's warm anyways, it's much harder on the motor than driving easy until the coolant is warm. The best thing to do is to fire it up, let it idle about 30 seconds to build oil pressure and drive easy. If you want heat sooner use the block heater. Yes 05's can also use the cruise control to adjust the idle. Smarty will enable this, as will the dealership and other tuners. With the truck in P turn the cruise control on, then press set. RPMs should go to 1100. Then use accel/decel to go up/down between 1,100 and 1,500 in 100 rpm increments. I use this feature all the time, to cool the motor after towing, increase load when idling in the cold, or provide more heat if I need to leave a kid in the truck in the cold.

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Perfectly normal. ~32° and lower it will go to 1,000 rpms after 2 minutes; ~15° and lower it goes to 1,000 as soon as you start it. Then if the ambient is lower than 32° and your coolant is below 180° it will do it again after 2 minutes of stationary time.

You don't want to interrupt this, it's a feature that helps the motor stay warm to prevent cylinder washing. Really you shouldn't be idling your truck before it's warm anyways, it's much harder on the motor than driving easy until the coolant is warm. The best thing to do is to fire it up, let it idle about 30 seconds to build oil pressure and drive easy. If you want heat sooner use the block heater.

Yes 05's can also use the cruise control to adjust the idle. Smarty will enable this, as will the dealership and other tuners. With the truck in P turn the cruise control on, then press set. RPMs should go to 1100. Then use accel/decel to go up/down between 1,100 and 1,500 in 100 rpm increments. I use this feature all the time, to cool the motor after towing, increase load when idling in the cold, or provide more heat if I need to leave a kid in the truck in the cold.

How cold is it ok to do this? I nearly always plug it in when it gets cold but sometimes it just doesn't work out. Like sometimes it'll be as cold as 10 without being plugged in. It sure rattles if I start driving at that temp.
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Like for me I might let it idle for enough temp to bring coolant temp up to 80-100*F and then leave by that time everything in the engine is well lubed up and the oil is starting to thin down a bit and more than safe to drive. By 140-160*F you can cut loose and kick that pig... :whistle:

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I personnaly think the best way to warm it up is to drive it. I start mine and let it idle for 20 to 30 secoonds and drive easy untill I see either temp going up or oil pressure dropping. Usually happens in 5 miles or so. Thats my 02, not sure if it works any differant for a 3rd gen

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I would start it, let it idle for a few seconds and drive it easy until its warm.

If your scraping windows then fast idle it.

But don't just let it idle to warm up, it's hard on a motor.

Is it hard on any motor or just these cummins? Just thinking about my days of truck driving and there's guys out there that are pretty fanatical about idling their big rigs till 120* or even higher before even starting to drive easy.
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Is it hard on any motor or just these cummins? Just thinking about my days of truck driving and there's guys out there that are pretty fanatical about idling their big rigs till 120* or even higher before even starting to drive easy.

It's hard on any diesel, there are Cat, Detroit, and Cummins bulletins about it. Min temp for full load is 160°, so use that as a guide.
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Without some sort of virtual loading Cummins diesel engines don't produce much heat. Idling a engine is all that great. But if you have a exhaust brake and/or high idle abilities then you got a different story. But for me to just start my truck and idle it will take a very long time to warm up and its not suggested. The problem is Cummins diesel engine are not ment to be operated at coolant temps below about 170*F. So high idle feature was designed by Cummins but disabled by Dodge. :duh:

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