• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Weeping on Valve Covers


FBBO Gold Member
FBBO Gold Member
Local time
2:18 AM
Jan 11, 2022
Reaction score
Fredericksburg, VA
I noticed that there seems to be a "weeping" of oil around the oil filter cap (first picture) and the PCV valve (second picture) onto the valve covers. I have installed a brand new filter and a brand new PCV valve and this odd problem persists. It almost appears that the weeping may be coming from the base of the stems (or whatever the heck they are called) that stick out of the valve covers that each is pushed on. Any ideas what might cause this? Is it common for this to happen? Could it be a symptom of a different problem? (Side note: I continue to grapple with the oil leak around the rear main area). Any thoughts would be greatly appreciated. Thanks.
IMG_8585 (2).jpg

IMG_8586 (2).jpg
That setup is a little different than my 66 - the pvc valve is on the right valve cover. But that wouldn’t make any difference as long as the pvc and the breather are plumbed to the correct points. They may have changed in 68 or 69. Are they original valve covers or replacements? The next time you have the covers off you might try sealing the inside around the base with something like Right Stuff which appears to stick really tightly.

I think the rear main sealing is all in the details - offsetting the seal joints and sealing the ends together. Apply thin coat of RTV on retainer to engine block seat area. Lightly super glue side seals in at upper end of retainer to ensure they don’t shift out of position. Seal over the retainer bolt holes in the gasket rail area after the retainer bolts are torqued to spec. Fill the recess behind the side seals with an application of Right Stuff or Ultra Gray RTV.
A few tests you can do with a vacuum gauge. #1 at the breather hose disconnect at the air cleaner base rig the gauge to the hose and see what it is pulling or not. Give it a few seconds, should be manifold vacuum or close to it. #2 at the PCV rig the gauge to the VC grommet to check for crankcase pressure. You will have some pressure but nothing like a pulsing gauge indicating a ring issue. I don't have specs but you might find them in the service manual. While doing the tests wiggle and push the VC grommets to see if it helps with the readings. I had a weep at the PCV on one of my BB and found a tighter grommet for the seal area on the cover and valve. like said a little RTV cant hurt. I remember a slant 6 with a plugged breather that would make the engine stall when warm. The PCV is supposed to be a closed system good n tight. Hopes this helps. Beautifull engine by the way.
Auto Transport Service