Hi Guys,

I've got a unique puzzle. I'm trying to figure out what I fixed, so I can make sure whatever it was ACTUALLY get fixed permanently.

I was starting to get a rough(ish) idle extra noise from the belt near the AC compressor. While investigating, I discovered that the Can-shaped device circled in the picture was pushing out air, making noise also. I thought the belt-whirring noise was coming from the AC clutch bearing, so I took the belt off to check it out. Without the belt, the bearing was smooth and quiet. I put the belt back on, fired it up and the idle was smooth, and there was no longer air being purged. What did I do? Is that canister purging air related to anything on that belt? (AC, PS Pump) Could the belt have been too tight causing something to malfunction?

1990 F250 4x4 with a 460 gas. (yes I know that picture is a 5.8, but the component circled is the same as what I'm trying to figure out on my 7.5L)

 

It has something to do with the smog system on these trucks Im pretty sure. I plan on removing mine when I get time, I can hear mine making a noise of it pushing out air as I drive.

 

Thermactor/air pump muffler. Thermactor system only injects air at cold startup to help cat function better. Vents its output the rest of the time.

Think I got the essentials right, if not the precise description.