Today I took down the main cat to inspect it and do something about the rattling/squeaky heat shields.

The problem is one of the brackets for the big heat shield had exhaust soot on it, and sure enough there is a pinhole leak where the weld for the bracket had broken off. No wonder it sometimes sounded leaky, and sometimes just rattley.

Can I have the hole welded over, or is it probably too rusty to weld anymore? If I grind/clean the surface, would a JB Weld hold up?

I'd like to just get a good high-flow cat, but 1) cost and 2) ECU? (I have a downpipe, stock intake and muffler, efini y-pipe).

Dave

 

You can weld anything to hold for a month or a year. If the area is suitable you could install an aluminum rivet. That would hold fine. It might not seal as well but wont harm anything. Jb might work fine.

 

JB Weld holds up under any stress you can throw at it. It has replaced the head gasket on my minibike.

 

I was thinking this might be the best answer. I'll report the results. I have a funny feeling this will longer than I expect.

Dave

 

Hmm, I really don't know if this will last long at all (the cat does get pretty hot).
http://www.jbweld.net/coldweld.html -- it's only resistant to 500F.
"Not recommended for use on manifolds, exhaust systems, and other engine components which normally operate at temperatures above 500º F."

 

Should be a no-brainer for a local exhaust shop to do a quick weld at the leaky spot. Heck, I'd take the cat off, go to the shop, have them weld the hole right there, and pay in cash.

I agree - JB Weld is good for many things, but I doubt it would last long there. The cats get REALLY hot, and there might be quite a bit of pressure coming out of the leak as well.

Dale

 

OK, sounds like I'll throw it in the trunk and take it for a weld repair. I hadn't gotten round to checking the JB Weld temp limits, thanks WaLien.

I have to say I'm disappointed by the corrosion and broken heat shield flanges. Are those things supposed to be solidly attached, or are they just folded under the inner heat shielding? Makes me wonder if it's worth getting another used one since I want it quiet and long-lasting. I actually thought about buying that nearly-new one listed for sale last month - I guess I should have inspected this thing sooner.

Dave