Jeaton

Ever since I had this truck(2001 F150 supercrew 5.4), I've heard a buzzing or grinding noise come and go under the hood, and I can't figure it out. My dad thought it could be a bearing in the alternator or from a pulley, but I don't think it's from that direction. Any ideas what it could be?

Usually the noise will go away when you give it gas, but once you let off of it, it'll slowly come back.

lifted98_f150

take your serpintine belt off and spin all the pullys even the idler pullys see if theres any spots that grind or have resistence if so replace it. also, could it be a heat shield rattling?

biigtiitan

The area you are pointing camera, i have seen the PCV valve buzz, grabe a hold of it, it is located at the top of the valve cover with vacuum lines going to it.

Biig

Jeaton

The PCV valve is exactly where I thought the sound was coming from, but I tried pressing it down and it continued to make the sound, maybe I need to press it harder down.

biigtiitan

Remove it and put your finger over the hole on the end of the PCV valve...

Jeaton

Wow, that was definitely it, I owe you one. Thanks a lot!