Any idea what this leak is?

[318 iS Cosmos]

Tensioners can weep oil alright, did you check the timing chain for any slack? To be honest, these cars are well known for oil leaks around the rocker cover & oil filter housing but you should be able to see these from the top of the engine.

[Dave]

Tensioners can weep oil alright, did you check the timing chain for any slack? To be honest, these cars are well known for oil leaks around the rocker cover & oil filter housing but you should be able to see these from the top of the engine.

That's a weird design, is the tensioner in an oil passage on these? Figured it would have have been behind a sealed timing cover.

I would have thought:
1. Rocker cover gasket
2. Oil filter housing gasket
3. Rear main oil seal
4. Front main oil seal
5. Sump gasket.