When I am driving about 60mph, and I barely hit the gas my truck makes a hissing noise. It kinda sounds like wind, but when i let off the gas it goes away. Is this an exhaust leak? I put headers on a few months ago and noticed one bolt was broke. I left it because it wasn't leaking. I also used the paper gaskets with the kit. It doesn't make this sound at idle. Does it sound like an exhaust leak? Should a new set of stock gaskets fix this? Thanks

 

Well Which Bolt Did You Brake And Yes,it Would Be A Good Idea To Put The Stock Gasket Back On To Start.with The Bolt Broken It May Have Warped The Flange.

 

Idk, bc he says it doesnt make the sound at idle or maybe thats because there isnt enough exhaust flowing through to make the sound. What about that vacumm line on the top of the engine, towards the rear, you can get to it w/o having to remove anything, is that still attached and working?

 

The bolt is on the driver's side against the firewall. The noise is more noticeable when the engine is at its normal running temperature. If you start it up and take off it sounds good. I'm guessing the metal is getting hot and stretching to make a little leak. It's been doing it for a while, about since i put the headers on. Will it hurt anything to keep driving it like this?

I'll look at the line tomorrow.

BTW where can you get some stage 8 header bolts? When I replace the gaskets i think i am going to put some better bolts in it.

 

sounds like an exaust leak. you will have pore performance and can damage/bend a valve depending on how big of a leak (when shut off cold air seeps in).