When the pumps are new they are stiff, and they loosen as they wear.  I
can't quantify further other than to say to look for corrosion and
pitting of the insides especially on the impeller.  Try to move the
shaft in and out...new should have very little or no discernable play.

-Dana-

Bradley Flubacher wrote:
>
> I have a replacement 1.6L diesel engine that I've been working on getting
> ready for entry into my '82 diesel vanagon.  I have both water pumps removed
> and I noticed that one's sprocket spins nice and freely (I can spin it and
> it continues to rotate by its momentum) whereas the other is a bit tighter.
> I have to pulley off the tighter one, but I can notice the difference.  I
> suspect even with the pulley on, it wouldn't spin much at all by its own
> momentum.
>
> The tighter one is from a newer engine.  It has the same part number with an
> appended A on it.  The gasket for the two halves of the pump looks like it's
> just silicon.  Maybe someone had it apart and put it together incorrectly?
> Maybe this newer pump is just different?
>
> I'm inclined the use the older pump and leave it intact.  Any comments?
>
> Anyone know where I can find the year of a 1.6L diesel engine from it's
> serial #? (*ME 518 083) (the number nearest the head)
>
> Thanks,
> Bradley Flubacher
> State College, PA