Spawning oil

Ok im back once more for another problem, I have a 1993 toyota celica gt 2.2L engine and as long as ive had the car its always had a oil leak. I was told it was the camshaft and crankshaft seals that were bad so I had those replaced not over 5000 miles ago. But for some reason ever 100 miles I have to add 1 to 2 quarts of oil. It doesnt leak unless its running and its a constant drip drip drip drip drip under the car. I know its oil and no other fluids are mixing together and its coming from the backside of the engine block. The oil pressure sending it mounted on the frontside of the head(looks like a knock sensor but I found out what it really was). Is there anything on the backside of the engine that can leak that bad? The whole back engine bay is completly covered in oil. Not fresh oil tho. Dirty old and new oil. Im lost on this one.