idle speed increase?

[Blane]

everyonce in awhile at a complete random time while sitting at idle for a few minutes my truck will increase to about 1100rpms. if i tap the accelerator or brake it drops back down. if i dont it will stay up there.

 

[jvencius]

everyonce in awhile at a complete random time while sitting at idle for a few minutes my truck will increase to about 1100rpms. if i tap the accelerator or brake it drops back down. if i dont it will stay up there.

That's normal operation.

 

[MUDWHISTLE]

It'll do that to keep the engine warm when its cold. shuts off when you tap the brake too.

 

[Blane]

when it gets warm will the idle go back down, or do i have to manualy make it do it (tap accelerator/brake)


ps. YAY! all the "problems" with my truck turn out to be normal!!!! lol

 

[DaveBen]

It should go down on its own. My 6.0 does.

Dave

 

[RickGmi]

Im not sure about are trucks, but in the trucking industry they found out that long periods of idle, like when a driver is keeping warm at night sleeping in his truck, the low idle would cause the oil to gather acids from the low rpm that woulds eat up main bearings, thats why the newer semi have automatic shut downs by computer if the drive does'nt raise idle past 700 for over 5 minutes,
Just thinking that this might be why Ford has it done automatically,
Just my thoughts.

 

[ranger boy]

It's called "high idle", it's good for it, I got it in the 7.3, get it in the 6.0

 

[Hoss 350]

everyonce in awhile at a complete random time while sitting at idle for a few minutes my truck will increase to about 1100rpms. if i tap the accelerator or brake it drops back down. if i dont it will stay up there.

The high idle feature is built into the Ford Powerstroke truck to prevent idling trucks’ cylinder and oil temps from dropping to dangerous levels. The high idle is totally normal.

Just in case you’re curious, the purpose of this high idle is to prevent incomplete combustion of the diesel fuel during periods of cold-temp idling. The engine kicks up the idle to get more fuel in there, raise temps, raise load, etc to keep combustion temps high enough to completely burn the fuel.

The consequences of unburned fuel include the washing down of cylinder walls (which can lead to scoring of rings and premature wear) from the fuel, unburned and incompletely burned fuel gunk buildup (which can clog stuff, not the least of which would be the valve stems and seats, which can lead to enough buildup that the valve cannot close completely and the piston whacks the crap out of it and your engine eats itself alive) and the acidification/fuel dilution of your engine oil from incompletely burned fuel washing down the cylinders and getting into the oil (which has obvious implications, when you consider that diesel fuel is a solvent, and solvents break down oils and greases).

Also, one of the more novel (and also more harmless) consequences is when raw fuel is ejected out of the exhaust in liquid form, getting your exhaust stacks all “wet” (hence the term “wet-stacking”). It is important to keep in mind that just like the term Xerox, which now is a term that refers to photocopies when in truth, not all photocopies are Xeroxes, wet-stacking has become sort of a generic term for “the negative consequences of cold-weather idling” and when someone mentions wet-stacking, they are referring to any and all of the consequences of cold weather idling, not just the fact that your exhaust is getting wet. The wet-stacking phenomenon is also referred to as “slobber.” It is certainly a sign of very advanced cold-weather idling problems, since by the time it gets out to the end of your exhaust pipe, it has almost certainly gotten into your engine oil, and has washed down the cylinder walls, and is adding gunky buildup to your valves.

If this happens, the best recourse is to get it hot again, by driving it under load (in order to burn off any gunk buildup), and then change the oil soon afterwards.

Of course, prevention is the best way to keep from having to worry about it, which is why Ford saw fit to install an automatic high-idle in your truck. Now, you don’t have to worry about it!!!

 

[doug young]

is this "high idle" only effected in the cold weather?

 

[whatabudro]

is this "high idle" only effected in the cold weather?

Yep