It's visable. Front of the engine above the oil sensor, a steady seepage. I lose enough coolant to overheat after 400 miles. Oil is fine, no contamination, excellant compression. It just runs through coolant. I suppose I'll have to replace the head gasket. The bolts on the exhaust manifold look intimidating though. My question is, should I try torquing the head down first and see if that doesn't stop it? '89 240 wagon.