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Exhaust manifold leak

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Old 04-24-16, 11:56 PM
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Exhaust manifold leak

Anyone experience the manifold warping and causing a leak?

I have a HKS cast log manifold and i'm pretty sure that's what is causing my leak.
After of years of driving the car with the leak, i'm finally able to see signs of exhaust leak around the gasket.

With people with similar problems have you been able to machine the manifold to fix the problem?
Old 04-25-16, 12:02 AM
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If you can see obvious signs of it leaking thru. You can have it machines flat again and install a new gasket. I recommend machining both the engine to manifold mating surface and the manifold to turbo mating surface while you have it off.
Old 04-25-16, 12:25 AM
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I would machine the manifold , that's what warps . Just did manifold gaskets on a dodge 383 with old cast manifold last week at work . With a straight edge . The two center primary's where the merge and coolant flows was warped almost 40 thousands compared to the the out side runners . The solutions were either machine the manifold or double up the gasket in the center and use copper rtv in between everything . Because the costumer wanted the truck back by Friday ( transmission rebuild , valve cover and manifold gaskets ) we did the second choice . As long as the manifold not cracked it worth it I think to machine . I'd like to find a old cast manifold myself for my heavy holset hx52 . Cast can take some weight
Old 05-22-16, 12:52 AM
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Use also a good quality metal gasket with some cooper spray sealant on it.
Old 05-22-16, 01:07 AM
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Absolutely a warped manifold. We'll machine it for free here if you just send it to us.
Old 05-23-16, 10:13 PM
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Thanks Glease!
I wish I was local to you. Thanks for the offer!
Your work looks amazing!
Old 05-24-16, 12:56 AM
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Got the same problem as op, got a hks manifold and can hear an exhaust leak. But there are no signs of it. Going to try and install a new gasket from Mazda. Hopefully it works or else I might have to machine it down.
Old 05-24-16, 06:54 PM
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Alexr101 ya even changed the oem gasket too.

After a couple of years I finally was able to see exhaust seepage out of the manifold.
Old 05-31-16, 01:27 PM
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I need to start lying to these machine shops. A handful of shops are turning me down when they hear it's for a rx7. It should never be this hard to machine a warped manifold.
Old 05-31-16, 02:00 PM
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It Shouldn't matter . They just being picky cause there's no money in it really for them . All they gotta do is re deck the thing . It's just cast iron . If they can deck blocks and heads , flywheels , etc then they can do a manifold
Old 05-31-16, 05:15 PM
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Originally Posted by unek87
It Shouldn't matter . They just being picky cause there's no money in it really for them . All they gotta do is re deck the thing . It's just cast iron . If they can deck blocks and heads , flywheels , etc then they can do a manifold
Exactly! this should be easy for them
Old 06-26-16, 12:22 AM
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Doesn't it look pretty obvious?




Old 07-02-16, 11:59 PM
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I encountered a slight leak so I used a piece of exhaust gasket material AND an OEM Gasket.
It worked rather well.
The reason I did it was that the OEM gasket is an arm and a leg.

Yours looks like poop by the way..heh,heh.
Old 07-03-16, 11:19 AM
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Hard to tell, theres not a clear leak on that gasket. I'd check the manifold very carefully for any cracks.
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