Oily drip from manifold vacuum port?

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Sep 11, 2018 | 10:48 AM

benji808

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From: Des Moines, Iowa

Oily drip from manifold vacuum port?

Bottom of the manifold, (if you marked the throttle and looked underneath the manifold from there it’d be hard to miss it) there is what looks like a vacuum port that a previous owner capped off with vacuum hose. It drips oily residue...not really enough to be noticieable but it seems really weird coming from that spot.

What is this, and is there anything y’all recommend doing about it?

Thank you!

Sep 11, 2018 | 12:29 PM

Jose

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From: Florida

blowby from the front somewhere.

Sep 11, 2018 | 08:55 PM

Doug

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From: Pacific Northwest USA

Assuming a Series III XJ6 here.

The goo is harmless.

Oily vapors....blowby, as Jose says.... from the crankcase are drawn back into the engine thru the breather at the front of the cylinder head. A pipe from the breather goes to the throttle body. The vapors are drawn into the intake manifold via the throttle body and over the years an oily goo accumulates.

Cheers
DD

Sep 12, 2018 | 03:41 PM

ronbros

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From: Austin tx and Daytona FL.

mine does the same thing, V12 ,mostly from the right side bank tho! runs fine no problems.
ron

Sep 13, 2018 | 10:26 PM

benji808

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From: Des Moines, Iowa

Does it need to be plugged, or just leave it open? Not sure if it would impact vacuum...

Sep 13, 2018 | 10:33 PM

benji808

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From: Des Moines, Iowa

Also is this somehow the vacuum port for the cruise bellows? Sorry for my ignorant questions, but that’s the only thing I can figure from the vacuum diagram...assume the other one underneath the manifold is the actual drain port...should I leave this one plugged or open (previous owner had an open hose on it)