Lube place changed my oil and 180 miles later it had lost 3 qts. Brought back and they "discovered" crack in oil pan about 3 inches long starting from outer ridge of bung hole. Stated that it was NOT done by them. Pan is not rusted at all, They repaired it with JB weld but I dont trust it. How much would it cost to replace oil pan, are they available new for my 1997 and Could there be any other explanation than they over torqued the bolt and cracked the bunghole?