The Ford Barn

larrys40 · 01-09-2017, 11:22 PM

my bet is an exhaust leak. You may have a crack in the exhaust manifold or possibly a gasket/issue at the block surface. Inspect the manifold well, on top, underneath where it goes under to mount to the block. Feel for exhaust gas while running.. careful not to burn yourself. look for sooty witness mark.

Unless you have severe piston slap.... or possibly a cracked/broken piston my bet is it's an exhaust leak. You can carefully try to tighten up the manifold nuts a little but honestly it probably needs a new gasket. For what you have I would use the one piece steel clad style - no gland rings ( probably would never fit anyway except on a new manifold).

I surface the manifolds together (preferrable if you're able to get that done) before re-mounting. Be watchful of the clamp connection and the alignment of the pipe to manifold and the flange. it's also a source of leaks and noise.
Larry

01-09-2017, 11:22 PM	#1
larrys40 Senior Member Join Date: May 2010 Location: St Charles , Missouri Posts: 2,032	Re: Snapping sound under load. my bet is an exhaust leak. You may have a crack in the exhaust manifold or possibly a gasket/issue at the block surface. Inspect the manifold well, on top, underneath where it goes under to mount to the block. Feel for exhaust gas while running.. careful not to burn yourself. look for sooty witness mark. Unless you have severe piston slap.... or possibly a cracked/broken piston my bet is it's an exhaust leak. You can carefully try to tighten up the manifold nuts a little but honestly it probably needs a new gasket. For what you have I would use the one piece steel clad style - no gland rings ( probably would never fit anyway except on a new manifold). I surface the manifolds together (preferrable if you're able to get that done) before re-mounting. Be watchful of the clamp connection and the alignment of the pipe to manifold and the flange. it's also a source of leaks and noise. Larry