I have a "howling" sound my mechanic is tracking down. We were pretty sure it was coming from the water pump. Replaced it. When I saw what he took out I was quite surprised. The pump had plastic impeller vanes. They were in good shape. But they were plastic. I thought plastic was replaced by metal early in the run. My 2006 was built within 50 cars of the end of the XK8 run.

I bought the car in 2010 with around 45,000 miles. It is conceivable (but not likely) the previous owner replaced the pump.

Even so, why would it be plastic?

Bit of a mystery.

... The sound went away after replacing the pump. It shortly returned. We are looking at the other pulleys as the source of the howl.

Thank you,

Jack

 

The latest revision for the water pump blades were also plastic, just a better quality than the original. There is a TSB somewhere explaining this.

 

my 03 had plastic and I put plastic back in, with the thin metal gasket and o-ring.

 

As far as I recall, Jaguar never fitted water pumps with metal impellers. They modified the spec after problems with the early plastic impellers failing but the replacement was still plastic.

The only metal impellers I've come across were aftermarket.

Graham

 

I bought one of those aftermarket metal ones. It looked like CRAP, did not have the O-ring set up and had a cheap *** paper gasket. Sent it back.

 

Agreed, I did exactly the same as you (sent it back) not only was the impeller rough, but the coolant ports were smaller than OEM.


Nothing wrong with plastic impellers when they are the correct type of material. The water pump with plastic impeller in my wife's BMW is still fine after 12 years and 180,000 miles. BMW tech did not recommend replacing it when I asked, and said his had 240,000 miles on it.

 

I had a howling sound on startup on a 2005 Ford V6 engine. Had both tensioner wheels replaced, the sound was worst. Started to remove fan in order to replace the water pump, found the harmonic damper had broken into two pieces, the outer pulley had separated from the hub. The two pieces are attached by a flexable material which fractures and finally failed.
Don't know if Jaguar used this design but you can get it checked.

 

I replaced the water pump on my 98 Coupe last year just as profilatic measure. The one that came out had black plastic fins and looked prefect, the new one had white plastic fins.
Flushed the system and refilled with long life coolant mixed with distilled water. No problem.
Regards,

 

I was thinking to do the same as White Bear. Now I think I'll leave things be. Anyone see any advantage to the metal blades?