No they did not recommend that I replace all 4 parts. In retrospect I guess I should have taken it to someone that was familiar with Aveo's. My son's father-in-law who is a mechanic(did not work on this originally) has determined that you are correct that one of the idler's did fail and now so far 14 of the 16 valves are bent. What is your recommendation? Cheaper to replace the valves or the complete top portion? Check for piston damage? Thanks.