Lately, the truck has been high-idleing. It will stay at 1000-1100 rpms for a while, till you rev it up a bit. Whys it doing this?

4900 miles.

 

forgot sig

 

i have the 4.6 (99) and had the same problem, it got progressively worse.

it started right near the end of my warranty, by the time i brought the warranty was over. this happened will driving as well as when stationary. i would have to rev the truck hard to get the idle to drop back down.

this was several months ago, and i have had no idleing issues at all since this was fixed at the dealership. i used to also have the rev drop at standstill, but again, that is gone also.

this is from an old thread below:



got my truck back yesterday from the dealership.

they fixed the high idle problem. i was afraid to replace parts when i wasnt sure exactly where the culprit was.

they put in a new air bypass valve throttle assembly. part-no. f65z*97f715 (not sure of the suffix as it didnt print on the ticket)

charged me 61.90 for the part. it started with 35,890 miles on it while i was in canada on vacation. being that i brought it in with 37,000 miles (when i got back from vacation) they would not do it under warranty.

it has been perfect since they have done this.

thanks to everyone who posted with info.