What's the current thinking on which is better. metal impeller or the white plastic. seems obvious, but I've seen (old) reports of the metal ones failing also, and they recommended using the white plastic instead.

Russ

 

All parts fail but stay away from stamped metal impellers. Theyre a straight blade, not curved or precisly fit to housing like the plastic and have terrible coolant flow. Beside the plastic impeller issue was a later 90's and early 2000's issue on original fit pumps. Its no longer a issue except the new 5.0litre

 

I bought metal for my 03, didn't like the fit and finish, went with orig type pump!

 

Get the current Jaguar spec (plastic) not a metal one

 

+1 on going for plastic. Several reports on the forum of issues with the metal ones.

Don't get too concerned with the white or orange colour of the plastic impeller on current replacement water pumps.

The original problem impellers were white and Jaguar upgraded OE were then coloured orange. However, recently a number of aftermarket replacements have gone back to using white again. A strange decision but it is 17 years after the problem was resolved!

Graham

 

A white impeller is not necessarily the same plastic as the early model.

 

I would think any old orig EOM like plastic impeller is fine. If you keep the rad fluid changed as needed I don't see why the need to go metal. I think most folsk get close to 100k out the orig units, I got 97k out of mine and with WP being so cheap and a easy repair i would not worry about metal if you have your car long enough to have to do another WP in another 80k+ miles.

 

The earliest V8's had an impeller that becomes brittle and crumbles. Most of these have been replaced, but there may be a few low mileage early builds still at risk.