Toyota Repair: oil leak in 1980 Toyota 4 cyl Pickup

Question
I have a 1980 Toyota pickup standard transmission, 2 wheel drive with the small 4 cyl. engine. It leaks oil at a rate of 1 quart per 50 miles. It is not the valve cover gasket, but seems to be coming from the front of the engine above the water pump and the fan blows it everywhere, eventually killing the alternater. I can't locate where the leak is.  What are some possibilities and can an oil additive slow the leak?

Answer
Hello, an oil leak of this size can't be fixed using an additive, check very closely above the water pump for a missing timing cover bolt, if you see a hole with no bolt in it then try putting a 10mm / 1.25 thread bolt in it, should be about 2 and1/2 inches long, another place could be the head gasket in the front between the head and the timing cover, a very common leak but lower on the engine is the front oil pump seal and gasket right behind the crankshaft pulley