exhaust fume resonating sound

What I originally thought was tappet noise, is actually exhaust fumes resonating in the exhaust manifold. This is accordaing to a BMW specialist. And I think I belive him because I came across a 330 and heard the same sound. However, is there anyway of damping or cancelling this horrible sound out?

Sometimes the exhaust mani heatshield gets loose and rattles. This is the first I've heard of someone having an issue diagnosed as such.

A tape of sound would probably help...and so would you using a stethoscope or hose as stethoscope to isolate the sound.

Try techron to clean up the fuel system...make sure you're using a proper LL-01 oil. See if that gets you anywhere. Also, some just rip off the heat shield...but I'm not so sure about that myself.

GL...hth

It may be the sound you hear is a leak AT the manifold,not IN the manifold. I know from installing headers on different cars and trucks when the gasket fails it sounds like a ticking valve or lifter. IMO your head to manifold gasket has failed. It's a pretty involved job. The only ways to correct it is to diy,or pay up for gasket replacement.
Edit: definatly confirm that it is a leak before pursuing a repair.

sent from my ATARI sc1224

Also check your spark plugs for any looseness. That causes a ticking sound too.

not the spark plugs for definate. Gonna look in to the other possibilities. Thanks