WRX Water pumps

[texaxile]

I'm seeing 2 different types of Water pumps for New age Imprezas, the old regular "impeller" type and a different "cast impeller". Apparently the latter prevents bubbling and cavitation at high revs.
As I'm due a Cambelt very soon I'll put a new Water pump on as well, anyone know which is better? (I think the Subaru ones are cast but not sure). ICP have a Gates kit with cambelt and water pump included, but is it better to get a genuine pump and Gates Cam belt kit separately?.

[vxr2010]

is your pump not working ? or are you on very high miles ? if it's ok i would just do cambelt tensioner and pulleys and yes i would use icp parts

[texaxile]

Not high miles for the year, but this is the 3rd cambelt it would have had. The car is an 04 and the previous owner changed it every 4 years, it's now due as it's at the 5 year mark since the last one.
The pump is fine, but I've read that as preventative maintenance it's worth doing while the water is drained an the cambelt etc all off. for the sake of a few quid it's the kind of preventative maintenance I think is worthwhile. That leads me to my question about the pumps, there seems to be 2 different types, regular impeller and cast impeller, I was wondering what the std Subaru fitment is. There is a bit of a price difference, to the tune of about £80 between them (£114 or £120 for the cast impeller as opposed to £35 or so for the non Subaru option).

ICP are good so I might give them a tinkle on Monday and ask. Whatever happens I'll be going for a full Gates kit with all the pulleys etc. I've heard and read some conflicting reports about Dayco and again, while they're cheaper, I think that Gates are worth the small premium.

I've been quoted £200 or thereabouts for a cambelt , Thermostat and water pump change and to refill the coolant system with new coolant, i'm supplying the parts though, that's only the labour charge, plus VAT. Reasonable?.

[vxr2010]

See what ICP say about the pump , the price seems fair to do all that as it's not a 5 min job

[Konan]

texaxile said:

I'm seeing 2 different types of Water pumps for New age Imprezas, the old regular "impeller" type and a different "cast impeller". Apparently the latter prevents bubbling and cavitation at high revs.

Have you got any links to good info on possible cavitation?

I sometimes find my track car climbs in temperature a little on the hottest of days and just backing off and shifting up 500rpm lower brings it right down again. I don't know how much of it is the backing off and how much is shifting early.

I've considered the possibility of cavitation being behind it so any reading you could point me to would be much appreciated.

[texaxile]

Sorry Konan I haven't, only some info relayed to me by Subaru themselves when I asked the difference and also some of the claims made by the advertisers.
I still haven't had time to speak to ICP and get their opinion. A good friend who builds racing engines said the only failures he's ever seen on a water pump is the impeller detaching from the spindle, and that's only twice in 20 odd years. As it's going on a standard car I'll probably opt for the cheaper one.