Heat. Yes of course. I assumed the plastic material was somehow
reacting poorly with water/coolant mix.

It is an interesting wear pattern on the one I pulled though. I'm
going to double check the housing for wear.

Cheers,

Neil.

On Feb 20, 2008 6:26 AM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> I guess I stand corrected regarding the composite impellers. I have not
> seen them. My bet is that any type of engine overheating would mean the
> end of them.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>
> Kenneth Wilford
> Sent: Wednesday, February 20, 2008 8:40 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Water Pump Impeller Damage
>
> Dennis, actually some of the newer VW engines have water pumps with
> plastic impellers stock from the factory.  And these wps are usually the
> ones that are run off of the timing belt.  The ironic part is the all of
> the aftermarket pumps have metal impellers.  So I would say if you are
> have a newer VW car (say after 2000) it would be a good idea to replace
> the water pump when you do the timing belt just to be safe.  The wps with
> the plastic impellers are very prone to self destruct (that is what I have
> heard too).
>
> Ken Wilford
> John 3:16
> www.vanagain.com
>
>
> -------------- Original message --------------
> From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
>
> > Who gets rebuilt water pumps for Vanagons or Jettas? Thoe worst I have
> > seen is the GMP brand. Stamped metal impeller that just does not move
> > enough water at idle. I have never seen a plastic or composit impellar
> for
> > a VW application.
> >
> > Dennis
> >
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of
> > Allan Streib
> > Sent: Tuesday, February 19, 2008 10:50 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: Water Pump Impeller Damage
> >
> > neil N writes:
> >
> > > Got some advice on brand names for replacement and was advised to
> > > get one with a metal impeller as the stock plastic one self
> > > destructs. I pulled it and sure enough, the plastic was
> > > deteriorating! Not sure why, but maybe something to do with a
> > > chemical reaction?
> >
> > By the way, if you get a "rebuilt" water pump then be sure to check
> > the impeller before you install it. I bought one for a Jetta years
> > back and the impeller had visible, fairly significant cavitation
> > pitting right out of the box.
> >
> > Allan
> > --
> > 1991 Vanagon GL
>

--
Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"

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