high idle when driving

mattl140 · Feb 9, 2015

80% of the time my truck idles high say 850-900 rpm when in drive and when i put it in neutral it idles back down any ideas? 99 f 250 thanks.

Arisley · Feb 9, 2015

If it is in Park for any time, the idle kicks up to keep the cylinder walls from washing down.

mattl140 · Feb 9, 2015

yes i know that i live in Canada and its cold right now.

Arisley · Feb 9, 2015

Sorry, missed that about it being in drive. I should read better.

Atsah · Feb 9, 2015

Isn't there a switch or something in the brake pedal that cut's the high idle out? Any truck I ever had the brake pedal would disengage the high idle.. When the truck is sitting and you touch the brake, does is bring the idle back to normal?

ghohouston · Feb 9, 2015

Yes, the brake pedal kicks it out of high idle. At least on all the big trucks, 6.7 cummins in the dodge pickups, 7.3's and 6.0's. Can't comment on newer powerstrokes.

SDS97_7.3 · Feb 9, 2015

ghohouston said:
Yes, the brake pedal kicks it out of high idle. At least on all the big trucks, 6.7 cummins in the dodge pickups, 7.3's and 6.0's. Can't comment on newer powerstrokes.

Does it on the newer trucks too

mattl140 · Feb 9, 2015

yes when i touch the brake it kicks off high idle. but in drive 80% of the time it idles high, when stopped at a light its idling high i put it in neutral and it idles back down then it will happen again

Atsah · Feb 9, 2015

mattl140 said:
yes when i touch the brake it kicks off high idle. but in drive 80% of the time it idles high, when stopped at a light its idling high i put it in neutral and it idles back down then it will happen again

What temps are we talking? IDK if it's the same but I have noticed my Taurus doing the same exact thing for the past two weeks (5F-10F for a high)..