my buddy wants to sell me his 98TJ for $1000. it's a 4cyl stick with 120,000 on the clock. here's the story of what happened to it. he was driving it up a steep hill near his house and he said the engine started wrapping pretty bad. then he said the motor started chugging. he said the oil pressure guage was still reading ok (ok, i know this is questionable) so he coasted it into his dads driveway about a 2 block away and shut it down. you jeep guys know of any common occurance in 98 wranglers that could make something like this happen? i know my buddy changed the oil in this thing religously every 3k miles. need a little help from you jeep guys as to what you think happened here. looked at it this morning. NO antifreeze in the oil. antifreeze is low though. none in the bottle and no visible in the rad. he did say it was NOT running hot when this happened. i started it up and it is wrapping real loud. not a valve chatter but a loud knock that appears to be coming from on top of the motor. engine has 120,000 miles on it. jeep is completely stock and sitting on 4 good stock size bfg at's. any ideas? cost of a rebuild? new short block from jeep? recommend a rebuild of original motor? is this common in the 4cyl tj?