What could have happend?
car suddenly stopped while driving. Had it towed home and thought for sure it was timing belt. Loosened rocker arms so that all valves were in closed position then set timing marks at tdc. Both marks lined up, then pulled off timing cover and belt looked just fine no problems that I could see. Checked cam gear and crank gear for brocken teeth found none. Took timing belt off and looks new it also appeared to have good tension. #4 spark plug badly damaged and can see some debris in cylinder. With belt off turned crank 1 full rotation but at tdc crank is very hard to move , all sparks plug had been removed. tried again and same results when reaching tdc. Any ideas?