I bought a Megan header from a vendor on this forum. I wont mention the name yet.
Ive tried everything to get the header to seal! Ive removed and installed the header about 6 times in 2 days.
The first time I installed it I noticed the leak right away of course. You cant hear the leak at idle. The motor must be under some sort of load. Slight revving and driving. Just like a rustling of a bag.
Drove it around like that. Sucked, I hated it.
Pulled the header the next day. Everything looked fine. The gaskets were perfect, no signs of leaking at all. The bottom donut looked like I didnt tighten the spring-bolts evenly but thats it.
I add some copper gasket maker/sealer; let it settle and reassemble.
Start it up..... Same leak.
I took it apart in like 10min. At this point its nature. Add a THICK layer of the sealer and try spacers on the bolts because I thought the bolts were bottoming out in the head and not tightening the flanges enough.
Assemble, start, leak.
So, today... I take my OEM gasket to work and buy a new donut from Autozone. The new donut actually looked better than the one supplied from Megan. It better! It was $10!!
I coat header gasket from Megan AGAIN with the copper sealer. I also add a coat on the donut. I figured might as well try replacing the donut since I didnt yet.
Put it all together AGAIN, start her up and what do you know? LEAKS! YAY!!!
Pull it all apart, add the OEM gasket against the header (w/ copper sealant) and the Megan gasket (w/ copper sealant) along with the donut (w/ copper sealant). Still leaks.
I actually had one of my coworkers cover my muffler as I revved. Leaked like a bitch! But I couldnt find where, the header was too hot to feel around. My guess, where they meet in the middle. Welds look sloppy and some dont even look finished.
All these leaking noises sound the same also. It never got better or worse.
All in all, my header is defective. It must be leaking at the welds or something.