oem one is plastic impeller, I had a new ish one break and never recovered all this bits but that was my first 14 golf. that's why I went to a metal one. and as far as the failing water pump noise to look out for, when the bearing went it was a long drone kind of sound, and then a squeal went it got so bad the belt slipped. that happened on the dually before I had chance to pull off. when the seal went I just lost coolant, no noise.