Are there any signs of oil leaking from anywhere else? I used to have a volvo 340 with a renault 1.7 engine, and oil got into the dizzy on that too.
The cause was a blocked oil trap in the sump breather pipe. There was sufficient pressure build up due to blow by to blow oil through the seals. It was actually coming out of several other places too.
I've never heard of this happening to any other vehicle, but its easy to test. Remove the oil filler cap and place your hand over it, there will be a pressure build up. Oddly, we found that at idle you could get a vacuum, i have no idea how (anyone know?). Anyhow either way pressure or suction will prove a blockage in the breather. In this case it was very obvious, but then the engine was old and worn.
I don't know where the k series is vented or whether it would be susceptible to this problem, but i though it might be worth a check before you go through the hassle of changing the seals.
Good luck
Will