exhaust leak getting worse

[vortec]

since installing my remanned 350, i've had a small exhaust leak on the pass side. it's getting worse. i'm almost certain it's wither where the exhaust flapper thing (for warmup) meets the manifold or more likely, where it mates to the flared y-pipe. i've tried high temp silicone (red) to make a gasket and it just blows out after about 20 miles. yes, i let it cure properly. easy since it's not my dd. i suspect i may have a second one at one of the air injection ports. but, no surprise, the fitting is seized in there and using a wrench on it just mashes it up. besides new manifold or pipe, any suggestions? it's giving me a headache, sometimes literally. i haven't been able to find a donut for it at parts stores

 

[shaun89]

hmm, sounds like u have a very stock engine, maybe some emissions stuff stuck on there...if you have the time, try taking off all the things that are causing leaks (emission tubes and heater risers) and if u can, grind it to bare metal and use some jb weld...if its not on areas that u need to get off again...other then that....i know you said you didnt want to but..a new manifold or headers...

 

[dyeager535]

No gasket needed on the EFE valve to exhaust pipe, IIRC, both are flared there. If you have leaks, trying to use sealant is only going to make things worse, since they won't pull together tight enough. EFE to manifold takes a flat gasket.

Truing up the surfaces may help the problem, but for that much work, headers.

 

[vortec]

hmm, sounds like u have a very stock engine

yeah. it's pretty stock. i've checked the emissions stuff, though. seems fine.

No gasket needed on the EFE valve to exhaust pipe, IIRC, both are flared there

i know it's not supposed to need a gasket, but i've been wheeling it for years at stock height and have no doubt dragged the pipes in the mud many times. wouldn't take much bend to cause a problem.

new house soon + tires for both trucks = i'm tired of spending money at the moment. at least headers aren't too pricey for gen I SBCs.

 

[dyeager535]

Yep, the problem is none of the exhaust gaskets are flexible, so they can't take up any space caused by something like you mention. They are meant to seal perfctly round or flat surfaces in stock spec, that's it.

 

[vortec]

so, it looks like all-new exhaust or ghetto-rigging some flex pipe in there (really not such a bad idea for an offroad truck) are my easiest options.