My nephew has a '01 tj with the 4.0 and 166,000 miles. I think the head gasket has gone since there is the "mayo" on the oil cap and it loses coolant (although the rad and heater core leak- maybe the cause of an overheating). My question is since glycol has been in the oil and may have damaged the bearings is it worth it replace the head gasket or just throw a rebuilt in?

Thanks