did he put a new belt on it as well? because the old belt will have stretched a lot. Make sure he put the correct size of belt on as I once put a belt on that was for a model of car,made 1 month later than mine,& it turnded out it was the wrong belt(the 1 i shouldve put was 10mm shorter.)AND it was the no1 car part supplier in scotland that maintained it was the right belt,when it wasnt.correct belt installed,& prob disappeared