I have a slow leak when the engine of my 95 Nissan Maxima is running. I have traced it to a spot on the back side of the engine. Behind the crank pulley, but apparently behind the timing belt cover. I have included a picture that is taken from just above and the right side axle (seen in the bottom of the picture). In the picture, the crank pulley is seen on the right. The bright spot in the picture is the apparent source of the oil, although I think it must be coming from behind the covers. Could the main seal be the problem? I have seen some posts about the timing covers needing to be resealed. Are they really oil seals or is it something else that is leaking? It looks like a pain getting those covers off. Should the engine come out? It leaks a quart over maybe 1000 miles. What are the problems if I just let it leak?