I have a fairly large oil leak somewhere above the starter. It doesn't seem to be coming from the back of the valve cover (taken off and replaced some time back) It will leak almost 2 gallons of oil (don't ask me how I know) in 500 miles. It seems to be much worse after driving, in fact it doesn't seem to leak (except for the amount that is already on the engine and running down it) when idling. I think it's something between the starter and back of cylinder head (where I can't seem to see) What is back there that can leak like this? It started off really slow, and about a week ago really increased. 
