Hey group,

So the other day when I was driving, I notice that the truck wasn’t slowing down when coming to a stop. Once I got to the light, the whole time while sitting there I was idling at 1500rpm. When I shift to park or neutral (still from 1500 because it won’t go any lower), it shoots up to 3000rpm. Talked to one guy that suggested I look for a vacuum leak, I did but doesn’t appear to be that. When I start the truck it shoots up to 3000rpm, when hot, or cold. The strange thing is that sometimes while I’m driving, the rpm’s will return to normal, but then inevitably go back to the current issue.

in essence,
Truck sits at 3000 while in park or neutral
truck while sometimes return to normal
doesnt matter if hot or cold
doesnt appear to be a vacuum leak

I’m just hoping someone out there might have a suggestion for me to try or a problem they might think it is. Any help, even if just a guess, is much appreciated.

 

No check engine light or codes, I presume.
Why doesn't it appear to be a vacuum leak? PCV system?....doesn't the 3.0l have a plastic vacuum tree? Split air handling hose after the MAF?
Stuck open IAC valve?
Wobbly/worn TPS? ...out of adjustment throttle cable?
Severely broken engine mount (goes to throttle position)?

How many miles are on this vehicle?