Manifold heat valve

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Aaron65

Aaron65

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I was out puttering around on the Dart today, putting new motor mounts in, changing the oil, etc., and I noticed the manifold heat valve was frozen.

I got it loose, but it's far from "free." Does anyone know which direction is open on one of these? Until it's totally free, I want to make sure it's letting the exhaust straight out.

Thanks!
 
In general.. The lever is in line with the unseen gate.
 
They have a few different stiles, Some have a weighted lever, some had a large disc.
Look at the direction that the spring "Un"-coils. rotate till fully open.
 
try anti-seize compound. course you know it goes on ALL bolt threads on the exhaust bolts, and all under the truck.
 
I don't want to hijack this thread, but I've got a couple of related questions. My son's '70 Roadrunner has an exhaust leak through the exhaust manifold heat valve's pivot. It's enough to leave tell tale exhaust dirt on the inner fenderwell and you can hear it (though it's not loud).

My first question is:

Do you think that the leak will be enough to mess up the readings that his O2 sensor makes? (he's got a comp controlled efi system that uses it for an input)

And secondly:

I really don't want to damage the factory hi per manifold by globbing JBWeld on it. Is there another means to seal the leak that will hold up to exhaust temps and not trash the manifold? - Hopefully something that could be done without having to pull the manifold off.
 
I can't think of a way without taking it off and not "trashing" originality. I brazed mine, but that wouldn't be viable for you.
 
Aaron65, if your engine is a 1965 (per signature), your heat riser has a round counterweight. As mentioned, the spring uncoils as it heats. There was a special fluid to free them sold at dealerships. Haven't heard of anyone buying it today. My guess is that wood stove glass door cleaner (Ace Hardware) might work fine to dissolve sticky soot.
 
is it true that a stuck manifold heat valve can cause a /6 to overheat?
 
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