I've seen many (well used engines) with the cover left off. Sludge (clutch disc dust, coolant and oil) can plug up the cover weep hole. If the goop level gets high enough, it can get onto the surface of the clutch and ruin the disc and maybe the pressure plate. If the engine was rebuilt and not leaking, I would definitely put a cover on it to keep out the road debris. Where is the oil coming from? Possibilities:
Valve cover and gasket
Lifter galley cover and gasket
Rear main seal
Oil pan and gasket
Oil pan drain plug
2X small welch plugs (rear access plugs) inside the bell housing area
I'm sure I'm missing something but someone will pipe-in shortly.
I buy engine cleaner at my local FLAPS, put on my "get dirty" clothes, cover (plastic bag etc.) the distributor and air cleaner, spray the cleaner on a COLD engine (hot cast iron can crack) and wait. Then I get out my pressure washer (adjust to very low pressure) and clean up the oil mess. Sometimes it takes scrub brushes. I do this in a place (definitely not on the concrete driveway) that doesn't kill the green grass that I just planted. When it's cleaned up, let it dry out. Drive the truck a little distance and check for fresh oil leaks.
Fingers crossed the oil isn't coming from the rear main seal or the welch plugs.
Last edited by buoymaker; 03/20/2021 9:25 PM.
