SC too driver side oil leak

[Aurel]

I have been chasing an oil leak around the driver side top valve covers, and I cannot make it go away. After a 10 min drive, there will be a very visible oil accumulation on the engine tin, which then drips on the oil exchangers and causes smoke form the engine bay.

I already went for the obvious culprits with no success:
- Retightened oil cam line with new copper washers.
- Removed top cam cover, sanded the surface, reinstalled with new hardware and silicon gasket.

What else should I look for? This is quite puzzling because the oil seems to accumulate fairly rapidly.

1978 911sc

[john walker's workshop]

Is the fitting below the cam line banjo tight?

[proporsche]

as John said this black arrow points to it .Of course the other side

[Aurel]

Originally Posted by john walker's workshop

Is the fitting below the cam line banjo tight?

Yes, that was the first suspect I checked.

[thetorch]

Oil compatible fluorescent leak dye added to the oil and a UV black light can sometimes work to find these. Clean everything first.

[john walker's workshop]

Clean with brake cleaner and watch.

[356911930]

Hi Aurel,

Have you checked the rockerarms to see if any walked and are now leaking? You may see oil on the inside of the cam cover where the ends of the rocker shafts protrude thru the bosses on the cam tower.

Best of luck,

Rahl

[Walt Fricke]

Doesn't a rocker shaft oil leak tend to get to the outside well below the engine tin?

The oil pressure sensor is on the right side, while the leak is reported on the passenger side (unless he's a Brit or the like). But there is an oil line with fittings both sides. And the rubber part of the oil line can leak if old enough.

I like the silicone gaskets, and, if one was damaged, that would have been noticed before re-use (which is the main reason to use these - they are reusable). When hot they tear easily, but after sanding the cover doubtless they were cold (or new). We are cautioned not to overtighten with these gaskets. My take is to watch to make sure you aren't squeezing the gasket out somewhere.

[john walker's workshop]

Not big on those rubber vc gaskets. You can't tighten the nuts. What's wrong with that picture?

[gomezoneill]

Get new paper gaskets and new valve covers.

[Aurel]

Originally Posted by john walker's workshop

Not big on those rubber vc gaskets. You can't tighten the nuts. What's wrong with that picture?

I had paper gaskets before and switched to the silicon ones if it would make a difference, and it did not. The picture is showing where oil accumulates on the tin (see it shiny below the cam line). I will check the nut is tight again, it is the most logical explanation for that leak, but I already tightened it. Will check the torque this time.

[Aurel]

I think I found the issue: copper washer behind the cam oil nut was ovalized, hence not sealing anymore. Now what should I replace it with for best sealing? I have 3 options:

-same new copper washer
-similar washer in steel
-or alu washer with wider sealing area?

Thanks in advance.

[Aurel]

And I found my answer below: the correct washers appear to be the steel ones.

How-To: Replacing a 911 Cam Oil Line Adaptor - Porsche Wiki

[proporsche]

nope, always alu washers on this....all 3 should be alu no steel ...so it was after all the black arrow pointing to your problem;-)

Ivan

[Aurel]

Originally Posted by proporsche

nope, always alu washers on this....all 3 should be alu no steel ...so it was after all the black arrow pointing to your problem;-)

Ivan

I just came back from a test drive and new washers did not fix anything anyways.
Then I found this thread and I have the exact same symptoms: #1 spark plug boot oily, and wet rocker arm nut, and oil filling in the tin, so it very much looks like a leaking rocker arm shaft.
Will try to retighten the nut first.

[proporsche]

well,take picture of the oil leak inside the valve cover..if one shaft would be loose check them all and mainly if they are in correct position installed..
Ivan

one more thing..i think your are not using the correct aluminium washers.......

[Aurel]

I checked my rocker shafts bolts and they were very tight, could not tighten any more. Also, I do have rsr seals, but even if they failed, the rocker shafts were mounted without seals originally, so this should not be an issue.

Maybe the valve covers are leaking into the cyl#1 plug hole, but I checked their surface on glass, so this seems unlikely. Still no resolution but I will figure it out.

Can 964 type valve covers be used on SC heads? I heard they seal much better.

[proporsche]

can you show me what alu washer are you using ? What ever i have seen so far, are the wrong types..
Ivan
this is the one which should be used left or right on camshaft through bolt and banjo fitting
https://www.pelicanparts.com/More_Info/90012300530.htm?pn=900-123-005-30-OEM&fs=0

[Aurel]

Originally Posted by proporsche

can you show me what alu washer are you using ? What ever i have seen so far, are the wrong types..
Ivan
this is the one which should be used left or right on camshaft through bolt and banjo fitting
https://www.pelicanparts.com/More_Info/90012300530.htm?pn=900-123-005-30-OEM&fs=0

I used the steel ones, and it may have been a mistake. I just found the correct alu ones in my stash, so I will try them next, after turkey day.

Thanks!

[proporsche]

Originally Posted by Aurel

I used the steel ones, and it may have been a mistake. I just found the correct alu ones in my stash, so I will try them next, after turkey day.

Thanks!

Happy Turkey day......
Ivan