oil leak from filler cap

[edgewood bronco]

Hi folks,
I just started driving my 66 bronco with a 170 in it. It's stock to the bone. Overall I'm pleased with the way it's running and driving, but...
I found when I got home that there was oil leaking from the filler cap, which made a lovely mess of my clean engine bay. Besides running with a rag wrapped around the filler cap and neck, does anybody have any ideas on diagnosing and fixing this problem?
Thanks!

 

[bubba22349]

Check or replace your PCV valve

 

[rbohm]

8) the next thing to do is check to see if the valve cover has a baffle under the filler cap. if not then fabricate one.

 

[Gene Fiore]

8) the next thing to do is check to see if the valve cover has a baffle under the filler cap. if not then fabricate one.

Or use a baffled rubber grommet if applicable to the cap you are using.

 

[edgewood bronco]

I'll take a look. Is it sufficient to give the PCV valve a shake and see if it rattles?

 

[bubba22349]

With engine running pull the PVC out place your finger over the end to seal it then remove you should be able to feel and hear it move to closed position.

 

[edgewood bronco]

I welded a baffle under the filler tube inside the valve cover.
It's a sheet metal circle just a bit larger than the diameter of the filler tube (half-dollar sized) with two tabs bent at a right angle to the surface of the circle. Those tabs allow about 1/4 inch clearance between the baffle and the filler tube so I can add oil.

I think it's a band-aid for another problem, but I've not been able to figure that out yet. My 223 six in my '62 is set up exactly the same as this one was before I modified it (except it has no PCV system), and it never does this.

 

[edgewood bronco]

An update on this... I ended up putting a plug in the oil filler neck and running a hose from there to a 1 quart oil container (it was vented so it wouldn't blow out), thereby catching the oil and keeping it from getting all over my engine bay. I replaced this engine ten days ago. As I was cleaning up the garage a bit today in the aftermath of the engine swap, I came to that oil container and emptied it. It was GREEN!!! Clearly I had a crack or leak somewhere and was getting antifreeze in the crank case.
I tore the engined down to be sure rain didn't get in it while it was sitting outside the past few weeks and so I could store it more compactly. I found it in unremarkable condition. No massive trauma anyhow.