I have a 4.0 2009 ford sport trac, I can be driving down the highway with my air

thanks much.have any sugg. on where to start??

It could be under the hood by passenger side firewall,, will be a small tube you are looking for that may be broken or disconnected....also may be in the manual control in the dash...heater control unit...listen for a hissing sound with engine running...

thanks again you've been a big help...

Sure!....it IS a vacuum leak ...somewhere!!!..Good luck.

found it,small white line coming though the firewall into the engine compartment, going to small pump like item, maybe a vacuum pump of some kind, hose was almost off the end of it, pushed it back up on the end of it , put a small tie tie on it, worked great all the way home from work today, didn't change direction at all...thanks again..

I knew a fellow Virginian could fix this... way cool...that will be $265.95 please!! LOL.... I'm near Roanoke. Franklin County actually..