Here's a strange one. 1988 F150 XLT Lariat 4wd 302 C6. The pass. side exhaust has the typical hissing sound of an exhaust leak. I've gotten under there three times now trying to find where it's leaking from, with no luck. I can't see anything, and I can't feel it. I've put my hand all around the manifold, manifold-y-pipe joint, and further down. It sounds like it is in the middle of a solid section of pipe in the y-pipe.

What's the deal? Could a valve issue mimic this sound? I can't imagine having a leak this loud and noticeable, and not being able to feel it.

You guys have any ideas?

 

i just had some exhaust work done today and the guy was using a long piece of rubber hose, held one end up to his ear and i guess was putting the other end around the exhaust joints to listen for leaks.

check the head gaskets and the manifold gaskets

also you could try putting some seafoam in the intake and watch where the smoke comes out

 

That or do what i do take a rag have a buddy cover up the end of the tailpipe and then you go and listen where it's coming out at, the simple but works it's how i found my two leaks.

Kyle