Does you guys experienced belt skipping (mainly at rear or may be side) problem? My E4 recently start making belt skipping noice (running carpet, 13.5 and 17.5) and when I look over the belt and pulley, they don't look too wear at all. I think I am going to replace the whole belt and pulleys, but I want to see does anyone hear experienced the same and know exactly where is the problem...?

I bet is mostly the rear belt....but really hard to tell. I have tried tighten the belt tensioner or loosen it...the problem still exist.