[BlueBoostedF250]

Hello,

I have a 2001 F250 7.3L with an AFE Stage 2 intake and a magnaflow exhaust. Everything else is stock. Monday I came home and tried to start the truck and just got a click after the WTS light went off. Voltmeter showed passenger battery was dead. Put in a new 850cca battery and tried to start the truck and it just clicked a couple of times before finally starting. I also tapped the starter with a hammer but I dont know if thats what got it to start or not.

The issue I am having ever since putting in the new battery is about 2 or 3 seconds after the WTS light goes off there is a "release of vacuum" sound that seems to be coming from under the air filter. It lasts for 1 or 2 seconds and stops. Has anybody had this before? Any fixes, or is it nothing to worry about? I dont remember hearing this sound before changing the battery. If I try and start the truck after the WTS goes off but before this sound, it cranks over hard with the WTS light coming back on while its cranks and eventually starts.

 

[BTBBT]

Not really sure, but is your HVAC controls in the off position? I sometimes hear that, but I thought it came from under the right side of the dash...

 

[BlueBoostedF250]

The HVAC controls are set to off. The truck has 104,500 miles and we bought it last month with 103,600 miles, driving it home from Portland, OR to near Sacramento, CA with no issues.

 

[rckstr]

I hear what sounds like a fart in the fuel tank, not sure if thats the same sound...

 

[jpciron]

Mine does the same thing, sounds like something opening or closing. I cant find it either but I think it has something to do with the air intake in the grille area of the truck.

 

[TTBadDog]

Depends upon how many times it has hit the Taco Bell drive thru. Actually it think it is something with the HVAC controls but I never gave it a second thought. My 03 has always made that noise from right side front under dash/hood area.

 

[BlueBoostedF250]

ok, I think I narrowed it down to the ABS module (?) behind the driver side headlight. The sound is loudest in that area and I can feel it vibrating when hearing the sound.

 

[mattp0o9i8u7]

did anyone figure this problem out?