Morning Everyone,

I have a 2000 F250 Super Duty . . . . while I'm driving I've noticed an air noise coming from, I believe, the passenger side of the motor or just in the general area of the firewall. It's a fairly faint high pitched sound. I can't tell if it is a sucking or blowing noise. Yes, I laughed too.... Anyway, It continues at any speed and only stops for a very brief moment when I change the position of my accelerator pedal. It stops if I push down....or it stops when I let off the pedal. IT'S ANNOYING AS HELL.

Any thoughts?

 

Does the sound change at idle when you first start the truck?

 

No...I don't notice any sound until I'm driving down the road.

 

If it's a gas engine, my money is on a vacuum leak or the smog air pump hose is leaking.

 

Look for a black plastic vacuum line near the firewall. The line runs to the hvac control in the cab.

 

gas or diesel?