I have a Toyota Rav4, 2006 base,/4 wheel drive, While driving slow speed I hearing squealing noise from engine, I had this problem since last 4 years. I showed this vehicle so many mechanic, they couldn't found out the actual problem. Is that noise from a bearing or a belt? And also I started to hear another "chirp" noise when I am pushing gas pedal. It is from the engine side (which started recently).