Changed the rear main yesterday while engine was still in car, started it up and drove it 30 min or so. Noticed still leaking, i even got the famous red seal from Dvorak. Any ideas ? the valve covers dont apear to be leaking or the oil sending unit either. After putting new oil in car the first few drops i did notice was the old darker or dirtier oil. The only thing i can think of is maybe a bad rear cap ? any suggestion would be appreciated. Could the oil be comming from one of the plugs in the back of the block ? I remember putting in a new cam plug but didnt use any sealer, just a thought. thanks