Hello,
I've got a 1999 td5 90, and just noticed a lot of black engine oil which appears to be leaking from the bottom left corner of the INTERCOOLER, there is also a lot of oil around that corner of the engine bay, lost a considerable amount of engine oil.
Any body got any ideas? :-/

Cheers,
Jason

Turbo bearings knackered or rings blowing. Either way you need to find out where the oil is coming from or the engine could run away on its own.

Is there any diffinative way to test either?

Take off the pipe from turbo to intercooler. Is it excessively oily? Expect a light oil film but not gobs of the stuff.

Take the breather pipe off that runs from the cam cover to the air intake side of the turbo. Run the engine and see if it is blowing oil or heavy fumes. If so its likely to be your rings that need attention as the crankcase is over pressuring.

Take the big pipe from the air intake to the turbo off and see how much play you have on the turbo shaft. Wiggle it with your fingers (engine not running) and look for any signs of the impellor vanes contacting the housing. There should be a very small, almost too small to see, side ways movement as the bearing is an oil film type which only works when the engine oil pump is working. Start the engine and have a look down the turbo inlet. Can you see any signs of oil? Is it blowing oil out of the turbo outlet when you rev it up? If so the turbo oil seals are knackered.

Thanks a lot,
will go and depress myself, lol.
Cheers
Jason