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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
You have umbrella valves underneath the valve covers. They are made out of rubber. When they get old (rubber gets hard) you can get symptoms like your describing.
I am not familiar with your air cleaner set up but a very small amount of oil can be considered normal. My guess would be the umbrella valves are due for a change even if just because of age.
If the oil amount is tolerable to you, then don't just replace because of that reason. If your pulling the valve cover for something else, then swap out the old ones while your in there. Your decision.
The umbrella valves are more flexible after they warm up. More rigid when cold. Meaning the valve does not "valve" as easily.
Oil is thicker when cold so not flowing as easily. Oil draining over night to low spots in the head and then venting out the head breather holes at first start.
Again just some guesses. But a certain small amount can be considered normal. If your worried about blow-by, do a compression check
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1997 Evo blowby
