Very loud headers..

[ericp501]

Turns out my project car had a clutch that was rust welded to the flywheel (SURPRISE!).. The car came with a set of aftermarket headers so I figured while I had the transmission out it would be a good time to put in the headers.  Kinda wish I hadn't now because these things are really loud.   I'm not talking from the exhaust end, I'm saying from the engine bay.. I pulled both the intake/exhaust manifold and put in a new gasket.. I tightened down the bolts really well too..  1 bolt on the very end of the header is broken, but it was like that when the stock manifold was on there so I don't think that much noise should be coming from that area..  Anyone else put on headers only to find it sounds like someone running straight pipes coming from the engine bay? 

[seattlejester]

Check for exhaust leaks? If it is aftermarket or been machined at any point, it may not be on the same plane as the intake causing parts of it to be loose. The one on the end keeps that side down, so if it has a bit of a curve not having it is going to allow the gasses to leak. There is a tonal vibration and shift, but it shouldn't be that loud in the actual engine bay. 

[BluDestiny]

It has to be an exhaust leak. Having that last bolt on the end broken leads me to believe you need to desk the headers and head mating surface. Sounds warped. 

[ericp501]

Following up on this in case someone searches and has the same problem.  The headers where not perfectly lined up to the block.  They were somewhat tilted (lower in the front higher in the back.  It was hard to notice with the intake manifold in the way.  It was so loud because 1/4" was exposed directly to the exhaust ports on the engine.  Lined them back up and now it sounds just fine, louder than stock but in a good way.