The oil cooler drips down the back of the engine - there's a drain hole at the back of the V. I had the oil cooler done at 130k miles, then at 155k had the crank case breather fail and cause failed oil cooler like symptoms.
It's hard to get a good look at the pictures (they're cropped), but am wondering if you potentially have a front main seal leak. Can you share links to the full sized images?
And hats off to you - the timing chain and oil cooler are the Achilles heel of the OM642. I'm reluctant to dig that deep into the engine, I don't have the patience to tackle a 8+ hour job anymore.