What is wrong with my car - somebody help? I have an awful rattle in my 172 which comes through the central panel internally when i am in fourth gear it happens from 40-45mph when accelerating and 50-55 in fifth sounds like a bad vibration but then it stops above and below these speeds, is getting worse and started to do it in third now?, externally it sounds like a high pitched sqweak, anyone heard about anything like this before?