ThackerSS

my engine has developed a loud "fluttering" type sound.. almost like soemthing is flapping its wings when I rev the engine up. Or go through the rpms. Its coming from either the header on the passenger side or under the valve cover. My header almostl ooks burnt ontop of it where it connects ot the head... does this mean the header has came loose? the higher the rpms get the louder the fluttering sound becomes.. or is it something much worse as a rocker or.. valve? ......

Hawkeye2

Sounds like the air check valve. You can make a restirctor plate from sheet metal.

You drill a 3/16th hole in the center of the plate and then sandwich it between 2
new stock gaskets. You use the gaskets as a template to make the plate. You need
some sheet metal (small piece) and 4 new stock gaskets (do both sides) and drill
and drill bits. Takes about 1 hour and works! I did it.

I can probably send you detailed plans from my office - pm me if you need to.

ThackerSS

AIR and EGR are gone, welded the holes shut on the headers.

I know for a fact its not it.. its coming from the passenger side , the header tube closest to the front of the car. It's definetely a fluttering type noise.

is it possible the gasket is messed up? Or maybe retightening the bolts will fix it?

Hawkeye2

If it's a gasket you may be able to feel the leak with your hand. The problem
is the cause may be not where you hear the noise, if you know what I mean.

Have you tried moving the throttle by hand and putting your other hand
near the header flange?

Racehead

Sounds to me like you have a collector leak. Start the car while it's cold and put your hand under there and feel around the collector, I bet you find your leak