When I start my truck I get this noise that kinda sounds like a exhaust leak but the weird thing is, it goes away after 10-20 sec. and I will never hear it again unless I let the truck sit for like an hour and start it back up but again it'll go away. Any ideas?

 

Yeah, its an exhaust leak. Warped pass. side manifolds are common on the modular V8's. Things swell up when hot and the leak abates.

 

Look at your studs on that side too. If they are broken off you will want to replace the trans mount at the crossmember to alleviate the binding.

 

Ok thanks guys I'll check it out. What are the fixes for it? Just replace the manifold gasket?

 

Depends what all is wrong but if you just have a blown out gasket then yes. If you have broken studs things get more complicated.

 

The manifold is usually warped. Almost always.

 

If the crossmember is intact and the trans mount then a warped manifold may very well be the problem but if the back bolts are sheared off then probly not a warped manifold

 

If it is warped spend $20 and have a machine shop surface it

 

How hard is it to replace that mount? I have to start looking into that. Had both sides replaced once and then the passenger side replaced again recently.

 

Not very hard just takes a little time. Won't take your whole day or anything though.