hi, my honda city model is ISDI 2003. 1st 3yrs, car noise quite low. But now, when engage gear with air-cond, seems got somtime sound "cha-cha-cha" when start enginer in morning or long parking. dunno is fan sound or air-cond sound but somehow still cool. previous honda service said bearing wear & tear. changed at >$ but still d same. pls advise