One problem related to loud engine noise has been reported for the 1998 Jeep Wrangler. The most recently reported issues are listed below.
Consumer was traveling about 70mph and heard loud noise, and back in lifted up. Front had dropped, and driveshaft was defective. Had it towed to dealership, and mechanic told him that crankshaft needed to be replaced. Consumer states drive shaft bounced off of street and hit floor board ripping hole in floor next to driver's foot.