Hi guys, just recently I noticed that when i turned off my truck there was a buzzing sound coming from my engine that would last for about 30 seconds or so. I believe i found the culprit but I cant figure out what it is.

Edit- Truck info 1990 f150 4.9l 4x4 automatic

This is what i believe is making the sound.



It is connected to this via the green line. If i unplugged the line, it would shut off.



video:

 

Looks like either the canister vent valve or purge solenoid

 

Awesome, thanks a lot

 

Mine does the same thing, I wouldn't be too worried.

 

Well my truck has been stalling when i stop and idling rough. Im getting code 22 so im trying to fix things that could have to do with a vacuum leak.

 

I have all new silicone vac hoses, no stalling or codes, and mine still does it. Like I said, I wouldn't worry about it. I think it's like some vehicles where the fan runs after the engine is off, it's annoying but it's supposed to do this.

 

Yeah mine does it too. No problems otherwise.

 

My 88 with the 4.9 does the same thing. Never really was concerned about it just figured to was things returning from the vacuum lines. 20+ year old parts and lines get cracks and leak but my truck runs great so all those parts are way down on the to get fixed list.

 

Idle air control valve, remove it clean it reinstall, if problems continues then replace it.

 

The picture you showed is the EGR valve.