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Old 06-13-2018, 06:32 PM   #1
jabborabbo
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Best way to find an exhaust manifold leak?

So I rebuild the carb and the old ‘67 runs like new...then the nasty click noise starts...it’s kinda loud when I first crank the truck, then it goes away when the engine warms up except it comes back when I accelerate, so I assume it’s a manifold leak, and I’m dreading what the fix may entail since the manifold has never been removed...so what’s the best way (or various good ways) to locate it?
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Old 06-13-2018, 07:38 PM   #2
GASoline71
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Re: Best way to find an exhaust manifold leak?

Take 2' piece of old garden hose and hold one end to your ear and use it like a "stethoscope" moving all around the manifold with the engine at idle. You'll know when you hear the leak.

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My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread.

The Rebuild of Creeping Death after the wreck

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Old 06-13-2018, 09:07 PM   #3
randy500
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Re: Best way to find an exhaust manifold leak?

Have someone put their hand over the end of the exhaust pipe(s) while you look for the leak under the hood.
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Old 06-13-2018, 09:32 PM   #4
CastIron
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Re: Best way to find an exhaust manifold leak?

I haven't actually tried this... but I wonder if you could just put a vacuum hose into a container of ATF and watch for smoke. I wouldn't recommend too much ATF at once, but a little won't hurt the engine.
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Old 06-14-2018, 09:40 PM   #5
BCOWANWHEELS
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Re: Best way to find an exhaust manifold leak?

your bare hand on cold engine running
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