My Grandson Has 1992 Ford F-250 7.3 V8 Diesel Trk. He has a oil leak when the truck starts when cold. It comes from driver side either on a line or on the block where the oil and coolant flows through. a big puddle. as the druck gets warm you can start it and you don'see it leaking. Using about a gallion of oil a weel . Any suggestions ? Thanks Darrell