4.3 v6 Sierra exhaust maniford mating surface defect

dlogvine

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I just purchased a replacement exhaust manifold for 1993 4.3 v6 engine. It has some manufacturing surface defects, pics are attached. Should I resurface them or with the gaskets it wont cause any problems? Or any other way to patch the holes if needed? Thx
 

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TurtleTamer

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I'd send it back. While it may be "ok" for a season or two, the low spots are going to rust and the rust will spread.
 

Scott Danforth

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It would be fine to use, however if it bithers you, send it back
 

dlogvine

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does not bother me a bit, since the manifold was a lot cheaper than the one without any defects but I wonder if there is anything I can fill the holes up with to stop it from rusting. There is plenty of surface for the gasket to catch on to not worry about the leaks. Thx
 

alldodge

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This one concerns me and I don't know of anything that can be used to patch. The gasket will probably leak some day

fetch
 

dlogvine

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This one concerns me and I don't know of anything that can be used to patch. The gasket will probably leak some day

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I will take it to the machine shop and ask them for an advice. Thank you.
 

dlogvine

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I checked out with my machine shop and they said that they could surface the manifolds if the gouges are not too deep, like 3/16". Will wait till the manifolds arrive and will take the bad one to the shop.
 

AShipShow

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First thought was to fill it with JB Weld and file it flat.. But on second though, I'm not sure that would hold up to the temperature since its right at the exhaust port.
 

Lou C

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Nov 10, 2002
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I think I'd send those back. Why pay good money for something that someone dropped on the floor in the factory? I got a set of Barr center riser manifolds when I replaced the exhaust on my OMC 4.3 and the fit and machining was good. Paint, not so much, I wound up repainting them due to surface rust even just from condensation. How were the flanges at the manifold to elbow joint? Those are actually more critical since a bad sealing surface can let water in the engine.
 

Bondo

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I checked out with my machine shop and they said that they could surface the manifolds if the gouges are not too deep, like 3/16". Will wait till the manifolds arrive and will take the bad one to the shop.

Ayuh,..... On the riser/ manifold face, you can do that,......

On that face, yer movin' closer to the valve cover, 'n there's darn little space to steal, Stock/ Oem,.....
 

dlogvine

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Machine shop looked at the manifold and told me that it will leak and they wont be able to surface it. The gouge is too deep. So Im sending it back.
 

Jcris

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Apr 23, 2016
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466
I would send them back. Agree with Lou, you paid good money and the gasket surface ought to be flat. Those look like returns from another customer. Might even consider buying elsewhere They're quality control should not have let that pass.
Jcris
 
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