Why would there be a lot of oil in the upper intake manifold?

LDZOLLER

MEMBER
1996 FORD THUNDERBIRD
12,500 MILES

I removed the throttle body as I want to bore it out and polish it. I looked into the upper intake and there is a lot of oil present. There is also some oil residue on the manifold side of the throttle body plate. Where could this oil be coming from and how do I fix this?

5 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Excessive crankcase pressure either from a bad pcv or the rings are worn.

Roy

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Friday, May 18th, 2012 AT 1:19 AM

LDZOLLER

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3 POSTS

A compression test would reveal a worn ring, correct?

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Friday, May 18th, 2012 AT 1:21 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

Yes, you must do both wet and dry and the difference cannot be more than 10-15 lb difference.

Roy

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Friday, May 18th, 2012 AT 1:23 AM

LDZOLLER

MEMBER
3 POSTS

Thank you for the quick replies. PCV valve is good, check it tonight. Does the lower intake have a plate on the bottom? I'm just curious as to how the oil makes its way so far up into the upper intake?

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Friday, May 18th, 2012 AT 1:28 AM

DJCL

MECHANIC
767 POSTS

Oil like slime coating in the inside if the intake was a co min problem with the 4.6 v8 engine. When thay got up in milage thay had some blow buy. Worn rings. Thay ran ok like that but would get problems with egr ports cloging up. Run an intake cleaner through it. Like run right.