I've been chasing down a vacuum leak on my 2003 S Type R and while poking around with my inspection camera I discovered what appears to be a large pool of oil in top of the engine in the vee under the supercharger. Is there a common cause for an engine oil leak that high up or should I be looking for oil leaking from the supercharger? I've replaced both valve cover gaskets fairly recently, but they were leaking from the low side prior to replacement. Could it be coming from there? I'm sure the supercharger is going to have to come off either way, but the weather has not been cooperating with such an undertaking. Just curious if anyone has encountered anything like this to get an idea what kind of fun I might be in for.

 

Is it definitely an oil leak? A coolant leak in that area would be more likely.
I hope I do not mix up my X308 with my S-Type or X-Type now, but I think it was the S-Type, where a "thick bent metal pipe" (to which a rubber hose connects from the front) connect down into the valley of the "V" and this metal pipe has a gasket, which wants to be replaced. Things are - as usual - designed in a way that access tot he nut or nuts of that bent pipe is close to impossible - but I made it somehow...

But first: Confirm that it is coolant and not oil...

 

Might be a two for one diagnosis. If there is a leak at one of the supercharger outlet gaskets that could cause your air leak and oil leak as the supercharger system is known to pick up engine oil thru the pcv system. A lot of owners install oil catch can systems to prevent that. You could pull the supercharger outlet piping off and inspect. Should be easy to do and easy to see oil drippings. Supercharger does not have to be removed to do it. Supercharger oil leak is not out of the question as you asked. Probably hard to get a look at the snout seal but that is where leakage would be normally. If you could get a smear of the oil and smell it the charger oil usually smells pretty nasty and is a very lightweight oil

 

It looks too dark to be coolant and doesn't smell of coolant, though I can't rule that out until I can get a sample. I did the valley pipe last year when I had the supercharger off to do some other work, so hopefully that isn't the issue.

That would be fantastic if I was able to get a two for one out of it! I'm going to try to snake a tube down there tomorrow and get a sample to see exactly what kind of fluid I'm dealing with. Hard to say for certain as I can only see it through the inspection cam, but it appears dark and viscous. I changed the supercharger oil about a year or two ago. The used oil that came out was foul AF, but would the (relatively) new oil have a distinct odor? I don't recall smelling it when I filled it, but my nostrils were still kind of singed from the stench of the old stuff. Anything else I should be looking for?