Hillsborough County schools get out May 25 for the summer break. ChaCha on! 7 years ago
Â· just now. Report Abuse. A cast iron manifold will expand and contract, the JB Weld will not. I think JB Weld is fantastic stuff (have some as we speak) but not for a cracked exhaust manifold.You can always check out their website: http://jbweld.net/index.php I only have experienced JB with cast though, if your manifold is another material you may get lucky.ource(s): Q: Will J-B Weld work on an automotive exhaust? A: Because of the extreme temperatures of exhaust systems, we do not recommend J-B Weld for use on exhaust manifolds and catalytic converters.
Exhaust leak symptoms will vary by where the leak is located. Also, the problems they can cause will vary by where the leak is located. A leak at the manifold between the manifold and the head will normally sound like a loud ticking sound. This kind of leak can create excess heat in the exhaust port, which can burn the exhaust valve-which will be an expensive repair. A leak somewhere between the exhaust flange and the muffler will normally sound like a throaty rumble. This type of leak is normally fairly easy and inexpensive to repair.