Impossible Oil Leak?

[Zed Head]

Just curious but I had an exchange about this in the past and proposed that maybe the cap would still seat well without the gasket.  Could you try yours and see?

I think I was just being obstinate and that I probably actually had a gasket on my old cap.  My memory was of looking at it and being surprised that Nissan used two hard flat surfaces to seal the oil filler area.   But the car was gone so I couldn't check it.

[chaseincats]

1 hour ago, Zed Head said:

Just curious but I had an exchange about this in the past and proposed that maybe the cap would still seat well without the gasket.  Could you try yours and see?

I think I was just being obstinate and that I probably actually had a gasket on my old cap.  My memory was of looking at it and being surprised that Nissan used two hard flat surfaces to seal the oil filler area.   But the car was gone so I couldn't check it.

I'm assuming all of ours have just hardened over the years and are no longer sealing

[Zed Head]

I'm trying to get past the assumptions.  The means to know are at hand...

[jfa.series1]

3 hours ago, siteunseen said:

#10

Wow Cliff, you are really digging deep into the archives! 

[Captain Obvious]

9 hours ago, jonbill said:

Well isn't CO clever.

Haha!!!   Mostly just lucky.

And yes... The term "O-ring" typically evokes a picture of a soft pliable contraption with a circular cross section. The seal on the filler cap is neither soft, pliable, or circular in cross section. It may have been soft and pliable at one time, but it's not now.

[chaseincats]

Just pulled the oil cap and it seems like there's neither an indentation on the valve cover nor in the oil cap.  What looks like a seal is molded plastic and you can see on the lip where oils been sneaking out.  I pulled my PCV valve and it's good - also the valve cover breathing hose is hooked up to the AFM boot so there shouldn't be any pressure building up in the valve cover to the point it would be blowing out of the cap which is what's really confusing...

Edited April 18, 2023 by chaseincats

[SteveJ]

Is it my imagination, or did you get the opening for the fill cap powder coated, too? It seems like that would be best left to staying the natural aluminum.

[Captain Obvious]

9 hours ago, chaseincats said:

Just pulled the oil cap and it seems like there's neither an indentation on the valve cover nor in the oil cap.  What looks like a seal is molded plastic

I know it's hard to believe, but this is a separate piece:

  "Are you sure about that five minutes??"  

 

[Mark Maras]

I'd be tempted to submerge the cap or the o-ring (if it's removable without destroying it) in wintergreen oil to soften it.

[chaseincats]

2 hours ago, Captain Obvious said:

I know it's hard to believe, but this is a separate piece:

  "Are you sure about that five minutes??"  

 

Wow really?  I'll get a flat head and hammer and try to bash it out or something tonight then.  Could I just go to home depot and grab a thick oring if they have it in its stead?  I really don't want to spend $20 to ship a 2 dollar part from thezstore haha

Edited April 18, 2023 by chaseincats

[chaseincats]

4 hours ago, SteveJ said:

Is it my imagination, or did you get the opening for the fill cap powder coated, too? It seems like that would be best left to staying the natural aluminum.

Yea the whole thing is powder coated minus the lettering of course.  You might be right about that but what's done is done I guess.

[cgsheen1]

So, none of you people live in Arizona?? Our oil cap seals were dried up, hard as a rock, and leaking 30 years ago. I still haven't found a replacement seal that I really like - most work but are a bit too soft.

2 hours ago, chaseincats said:

Yea the whole thing is powder coated minus the lettering of course.  You might be right about that but what's done is done I guess.

There's always 400 grit and a hard block...