Help: This wierd noise is killing me

[speedmetal6.6]

Hey everyone, I asked this in a previous thread and got some feedback but I still cant find out whats causing this. I got my truck out of the shop for the head gasket job in may and when I got it home I sraight piped it. I tightened everything down good and have checked it over and over. At idle or driving it makes this eeehh eeeeeeh sound and it is very intermitten it may last 1/2 a second you know like a chirp or it goes eeeeehh for like 20 seconds with up to like a 2 min pause in between buzzes. Its making me crazy. When the truck is idling and it makes that noise you can touch the tail pipe and it will stop, but I cant find anything loose or that it is rubbing on. You cant make the noise happen but when it does you just push on the tail pipe and make the exhaust move and it will stop and you let go and it does it again or it may not for a second or two or like I said a minute or more. Please give me some ideas as to what this could be , I'm about ready to change the whole exhaust system. It really makes the truck sound like a pos

 

[05lly2500hd]

Hey everyone, I asked this in a previous thread and got some feedback but I still cant find out whats causing this. I got my truck out of the shop for the head gasket job in may and when I got it home I sraight piped it. I tightened everything down good and have checked it over and over. At idle or driving it makes this eeehh eeeeeeh sound and it is very intermitten it may last 1/2 a second you know like a chirp or it goes eeeeehh for like 20 seconds with up to like a 2 min pause in between buzzes. Its making me crazy. When the truck is idling and it makes that noise you can touch the tail pipe and it will stop, but I cant find anything loose or that it is rubbing on. You cant make the noise happen but when it does you just push on the tail pipe and make the exhaust move and it will stop and you let go and it does it again or it may not for a second or two or like I said a minute or more. Please give me some ideas as to what this could be , I'm about ready to change the whole exhaust system. It really makes the truck sound like a pos

Your exhaust is rubbing somewhere, I had the same noise and very annoying, turned out to be my downpipe(from twins) was rubbing on the squared corner of the exhaust manifold.
With truck off, everything looked fine. Let truck idle and crawl under and follow the sound, I bet you'll find somewhere that it rubs and then clears, rubs and then clears.