After having my MAC headers on for a while now, I have noticed a "fluttering" noise when I get on it. Im not sure if the bolts are backing out a little bit because i have tried tightening them and they dont move. A friend of mine who works for a chevy dealer said it might be the PCV valve trying to regulate the air flow and that is causing the fluttering noise that I hear. Is this possible, or do I have a header leak???

Oh btw, someone suggested opening the hood and holding hands over the exhaust while the car is running and listen to the motor to see if it makes the noise at idle, when we did this the engine was whisper quiet. I just dont understand why it makes this noise when i get on the gas a little bit. Any ideas???? Let me know.

 

Sounds like an exhaust leak. Did you put a gasket inbetween the headers and the y-pipe? Also it might be your exhaust manifold gasket. What brand did you use? I used Fel Pro and no leaks at all.

Travis

 

Im not sure about the gasket between the header and y-pipe. But i just used the gaskets that they gave me with the headers when bolting it up to the manifold.

It cant be too bad of a leak because before the headers and the nittos i did a 14.3, then after the headers and nittos i did a 13.8. It is just annoying to hear that noise. Thanks for the reply. Maybe i will try and replace the gaskets between the headers and the manifolds.

 

I have recentely installed MAC headers as well. I'm also familer with the "fluttering" sound on acceleration. I had an exhaust leak at the EGR flange that caused part of it. This past weekend I hopefully sealed it. The flutter is still there. My installer rode with me to listen to the sound. He assured me it was not another exhaust leak. Seems to be a combination of valve-train noise and exhaust gases hitting the thin primary's. It's annoying.

My headers did not come with a gasket for the header to Y-pipe flanges. I assume yours didn't either. May try some high temp cooper sealent. I haven't used any. Never notived any leaks at idle.

I've checked for other exhaust leaks and loose spark plugs. I have just about decided the noise is normal for these headers.

Michael

 

So that noise is not an exhaust leak???? That sucks, the noise is very annoying.

 

I'm not saying for sure that it's not. I just can't find it. I also edited my first post if you didn't notice.

Michael

 

Yeah same with me, I dont think i had a gasket at the y pipe and header connection. I dont really think it is a leak as well because it is not at idle, only when i hit the gas. Dont get me wrong, I love these headers, but it is good to know that someone else has the same noise. That makes me believe that it is just the way the headers are made.