Huge oil leak/weap
 

I recently changed the oil and since I've incurred a huge leak/weep of oil from what I thought was the rear main seal. Instead, after some heavy degreasing I discovered the origin of the leak.
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It looks like it may be the transmission adapter, but I'm not sure. I can't tell where the leak is coming from. It almost looks like it could be a crack
Transmission Adaptor-3.2/4.0 Litre - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Heritage Parts UK

Originally I thought the leak was coming from the rear main seal, but instead it's just a small leak from there and the rest of it is just leaking from above.

Any insight on this leak? I'm loosing around a quart of oil a week if not more. I'd prefer to do the work myself. I think I can get my hands on an engine lift if needed.

Not doubting your diagnosis, but are you sure its not coming from the camcover "D" seals, particularly the exhuast one. It is basically immersed in oil whenever the engine is running.

That leak does run around the back, and down around things and drips off the lowest point.

Many a rear main seal, mainly the V12 engines, has been blamed/changed, only to find those "D seals the culprit.

I'm quite positive it's not the D seals. I recently replaced the camcover with one that's been freshly powder coated. I've also been checking around the D seals with clean fingers and they're fine.

My brother took a quick look at my pics, and he said it looks to be leaking near the starter, still resulting in a need to replace the rear main seal.

OK.

Simple fix, out the window.

Only question I have, and I have NO answer:

Where is the overhead oil feed on the AJ16 engine. Since there are NO external pipes, as in the older engines, it MUST be via the head gasket.

Someone will have the answer I am sure.

the upper feed is through an "o" ring in the head gasket but its up front above the dizzy replacement device/tensioner, poor design (IMHO) as they tend to leak ( mine does) and require head removal to fix AND will more then likely do it again .

There is a section like a U-tube which connects the inlet and outlet holes for an oil cooler, where none is fitted. It is near the oil filter, and has a rubber O ring at each end, which can leak. Could you have disturbed it while fitting the new oil filter?

I don't think I've disturbed anything when replacing the oil filter. Ive been checking the suspected leak area the past few weeks and I can't seem to find exactly where it's coming from still. At this point I'm sadly getting ready to sell the car. This coupled with the other age related things happening.

You can always find an oil lead if you are persistent. find someone that can put the car on a rack. Spray clean it completely. Spray talcume powder around that area and drive the car a short distance. Put it back on the rack and it should show up. We do that with aircraft engines all the time. And they do leak.

Don't forget. We just had a member of this forum reach 300,000 miles with his X300. Proper care I'm convinced they will last a lot longer.