All:

I've had these beautiful headers for a little over a year with no noticeable leaks.. However, lately, when I turn off the car after it's been hot, the headers make a cracking sound as the car cools down (one crack every 10 or so secs). Is this a sign that the welds are starting to breakdown? Or just the metal cooling from being hot?

-M

 

just the metal cooling from being hot most likely.. i wouldnt worry too much.. the metal has been expanded and contracted many times in the last year and this is just a "sign of age" on a low/mid grade exhaust piece..

 

I think your hearing somthing else. Not the mani cracking. If he mani cracks it cracks, and your car will sound like a bucket. people should start jet coating there after market manifolds to help stop cracking anyway!???

 

I never said that the mani has a crack. I said it sounds like a "crackling" sound ("TINK"). And it is coming from the headers.

-M

 

Eventually it will crack. My Megan is cracked right now. Thus my car has been deadlined, by me for over a month now. Sucks. A gusset on the megan O2 would prevent the cracking.
The crackling you hear is the cooling of dissimilar metals at differant rates. No worries, for now.........

 

Is your header wrapped in fiberglass wrap?

 

pretty much every metal expands when its warm...dont worry bout it

 

ive had my megan manifold on for under a week, and i hear this tick on cool down also. i would go with what these guys are saying, definatly normal.