I have a 98 intrepid 3.2 liter, bought new in 98. 114,00 miles. a few months ago it blew #1 plug out, threads and all. Had plugs put in at dealer 6 mos earlier, thought they might have just not tightened. put in insert and new plug. checked other plugs, ok. 1 month later, blew out #5 plug. put in insert and new plug. three days later check engine light came on, car ran hot, stated rattling, sounds like valves. also lost power. towed home, let it sit a feww months, cranked, still problems but no codes, battery was dead. checked compression 210 (if gauge is correct) on all but #5 it was 180. any suggestions before I tear it down?