engine vacuum at oil fill?

ive done some work on my 95 s/c and the other day i noticed something and it may be nothing but im not sure. when i took off the oil fill cap there was a good amount of vacuum there and the car even ran a little diffrently. im wondering if my lower intake gaskets may be leaking or maybe i did something even more stupid and installed something wrong

Hmmm... isn't that normal?

maybe, just never noticed it before. ive owned this car twice now and the car was sold twice between now and the previous time i owned it. both owners beat the car badly (one drove it from northern indiana to georgia with no supercharger oil). i noticed that the intake and supercharger bolts were mixed up when i changed the blower so i dont know how deep the people went into it. could be worried about nothing but thought id check

I think a little vacuum is better then a little pressure. Your pcv valve should maintain a little vacuum. May just want to pop in a new one if you never have.

Yes, there should be vacuum at idle, but not like a vacuum cleaner.

lot like vacuum cleaner. do you guys think im headed in the right direction with lower intake? or what else should i try?

I don't see the lowers doing it.

Thinking about this..the lowers have intake and water passages only. There is quite a bit of material and added sealing lines between the oil return areas and the intake runners. Vacuum like that is typically a pcv issue. Meaning when the PCV clogs it allows vacuum from the intake manifold to be pulled on the crankcase. Where as when the pcv functions properly it shoudl keep any vaccum from being pulled on it, only relieving pressure from blow by etc.

First and cheapest option is replace the PCV. Cheap part, but you won't find a gasket at the parts store, and it's not needed. Just use a thin layer of RTV when you put the PCV cover back on. If the old PCV rattles freely, you likely have other issues. Can't say I've ever heard of someone having a lot of vacuum pull at the oil cap.

Ya, definately replace the pcv if you've never replaced it before first, this should solve your problem

ill do it today. and will post results. and thanks for all the info.

done. running much better thanks to all

Was it the PCV?

i hate to admit it but i forgot to check the valve for rattle when i changed the supercharger and it was stuck, kinda feel a little dumb right now...

...not as bad as leaving the connector off the airflow sensor when replacing the air cleaner, or leaving the gas cap loose...

Albertj

Good, I am glad you fixed your problem

Checked or not ... it's nice when things are an easy fix. Smile and have a beer.

i think i will