Water Pump rotor - plastic or metal?

Unread post by **Duracell** » 26 Aug 2011, 14:34

Has anybody got any views on which is best?

I have recently bought a Valeo water pump from ECP in preperation for a cam belt change on my wifes C5 2.0 HDi - I chose this over the cheaper Circoli pump as I thought it may be better quality. The Valeo has a plastic rotor and a Circoli pump which my daughter has waiting to go into her Xantia HDi (same pump) has a metal rotor.

Have I paid more money for a lower quality pump or have they resolved the historical issues with plastic rotors?

I've tried to find out from the Valeo technical people what type of material is used in their rotors but they have no idea.

Gibbo2286 · Unread post by **Gibbo2286** » 26 Aug 2011, 15:41

I can only say from experience that I've seen a few plastic ones fail by the rotor coming adrift from its spindle, never seen the same with a metalt one.

wotwot · Unread post by **wotwot** » 26 Aug 2011, 17:14

Not a technical answer but I got the cheaper metal fin variety.
The old plastic one i pulled out although leaking was not making any noise.
But It did'nt have a single plastic fin left on it.
Must be in the system somewhere causing an obstruction.

addo · Unread post by **addo** » 26 Aug 2011, 22:53

I'd suggest plastic is not a good idea if your pump changes run by years not mileage (ie; when four years are up the mileage is not at the recommended change point). Many plastics seem to be embrittled by the action of dissolved chemicals - another good example being the heater pipe elbows.

The other caveat on plastic fins, is freezing - I'd much prefer a metal impeller if there is possible ice or sluch in the system!