oil leak from just below the alternator. What is it? Is it common? DIY fixable?

[Jinster]

Hi there. I am a long term owner. I have had my MY97 Tip for 21 years now and counting. Done around 300,000km. It's one of my two daily drivers.

 

The car has been very reliable but I have noticed a constant oil leak for years - something like 0.5L loss every year maybe, so nothing drastic. But the leak is very real as I have a constantly wet oil puddle on the floor at the same spot.

 

Anyway, I finally got around to opening the access hatch and I think I can see where it might be leaking. See photo.

 

This is the only part of the engine that's oily wet. It seems to make sense to deduce that given the alternator is dry, and that oil runs downwards, it's this part here, circuled in red, that's leaking from the seals (assuming there is a seal in there behind those bolts). My question is: what is this part of the engine? Is it oil running inside that clamped hose? Is this likely a seal problem or should I simply tighten the bolts? That big bolt on the top left is very distinctly different from the rest. What does that one do?

[Jinster]

I have since worked out that this part is the crankcase cover and that there is a gasket behind it.

 

It looks like it should be quite straight forward a job to DIY.... It might just be that I need a new gasket and that's it...

 

When I take off the cover, will there be coolant or oil leaking out everywhere? Or is this part of the engine too high up to have oil or coolant when not running?

 

Is it actually coolant or oil inside this thing? The large bore rubber hose would suggest coolant... you wouldn't run oil that way, would you?

 

I actually do have an coolant leak also... something like 500ml per trip - which is why I opened the access hatch in the first place, suspecting the coolant pump... but judging by the wet sludge, maybe it's leaking from the crankcase cover?

 

What adds to the confusion is the parts website referring to the crankcase lid as "crankcase water duct".. which implies coolant inside? But a quick google on "crankcase water" reveals it being a bad bad thing of a blown head-gasket/oil water mixture....

 

https://www.design911.com/p/porsche-996-crankcase-water-duct-99610102102-99610102103/

 

Does anyone have any tips and experiences on doing this job? Thanks in advance.

Edited April 14 by Jinster

[JFP in PA]

There will be coolant behind that item.

[Jinster]

Thank you.