Diagnose my drip please...

[Quasimoto]

My car has been bone dry underneath for the last couple of years, but in the theme of 2020, I noticed a pretty good drip under the 2-3 cylinder head area.

It doesn't appear to be the valve cover, so I did a quite a bit or reading old threads. They seem to point at either the oil return tube, or possible a rocker shaft leak.

(At the same time, one of the inboard oil tube seals on the RH side has started to weep down the case, just no drips yet. Shoulda never said that.)

The recess under the oil tube is very wet, but as you see in the pic, the oil has spread along the edge of the cam carrier, ulimately dripping off at the front, and I can't really tell where it's coming from.

So, I'd love to hear your thoughts on what the leak might be and how to proceed.

Thanks

[991gts6s]

Engine out top end rebuild.. leak is from the metal to metal sealant on the cam housing,

[proporsche]

1st i would check your rocker shaft-pins if they are loose --most likely i`d say...or if they are in the right position in the camshaft housing...take a picture and we will let you know once you take the covers off.If you find any oil on this place(on pic) it is the the rocker shafts..

[Reiver]

Second the rocker shaft issue....

[Quasimoto]

Thank You!
I will get the valve cover off and have a look this weekend...

[Peter Zimmermann]

Try to photograph the oil return tube o-ring areas. This is a problem when the car in question sits unused for a few days or more.

[kuba_kuba]

I have exactly the same looking oil leak. Decided to de-grease and clean the bottom of the engine to see where exactly it was coming from... lo and behold it travelled from the oil return tubes.

[Funracer]

You all must have some clean cars. I cannot even see a leak.

This is a mans leak:

[proporsche]

fun ..yes some people`s 911(like mine) have no leaks ..plus on your 911 the tubes were installed the wrong way;-)

Ivan

[Funracer]

Ha yes I am envious. Ready for my post holiday leak attack.

[sigchuck]

I’d echo the rocker shafts/shaft seals. I had a leak develop on a spotless engine with around 1000 miles on it that presented in the exact same place on cam towers. The old school engine builder didn’t use the RSR seals (surprisingly there’s a lot of debate around their use based on some Pelican threads), but that turned out to be the fix for the issue.

[Quasimoto]

Originally Posted by proporsche

1st i would check your rocker shaft-pins if they are loose --most likely i`d say...or if they are in the right position in the camshaft housing...take a picture and we will let you know once you take the covers off.If you find any oil on this place(on pic) it is the the rocker shafts..

Finally got out into the garage to have a look. The cover was dry in the areas shown in your pic.



No oil inside those areas of the head.




Tried to get a pic showing the location of the rocker shaft pins...

[proporsche]

that is a good news for you..can you take a picture straight towards the oil return(from the side) tubes so we can see what the o rings looks like...and one pic from bottom up so we can see the place where the camshaft housing meets the cylinders heads?
it is very possible that Peter Zimmerman was right and your oil return tubes o rings are leaking..let`s it

Ivan

[Dan J]

Oil return tubes

[Quasimoto]

Originally Posted by proporsche

that is a good news for you..can you take a picture straight towards the oil return(from the side) tubes so we can see what the o rings looks like...and one pic from bottom up so we can see the place where the camshaft housing meets the cylinders heads?
it is very possible that Peter Zimmerman was right and your oil return tubes o rings are leaking..let`s it

Ivan

Not sure if I got enough light to see the O-ring very well...

[Quasimoto]

I don't think the exchangers have ever been off the car, so I'm not looking forward to that, but I am relieved that it's not the rocker shaft issue!

Thanks to all for taking the time to look and share thoughts!

[991gts6s]

those are not looking bad studs .. soak em in pb max for a few days... they will come right off..

[Quasimoto]

I hope that’s the case!!

[proporsche]

yup replace the oil return tubes .Those o rings you have on them are orange and those were from the 1990`s or even original..Get yourself set from our host -just not the aluminium types and you will be all-set

No need to take off the heat exchangers for this job..if you need write up how to go about it let me know

Ivan

[pors1968]

I would clean engine and check oil cooler.Oil does not goes up it only dripp down.Oil return tube would on list to do.