Hi everyone,

New here but have lurked here quite a while. I'm doing the water pump on my '99 XJ8 and the Airtex AW4124 I received has a black impeller despite seeming brand new and being of the 2 piece metal-bodied design. I have had a look around trying to source a white impeller version (interestingly the water pump I took off was a white impeller with a one piece metal body and plastic sealing face) and it seems like everyone is selling the black impeller version, which I find odd if it was superseded many years ago. I can't seem to find the metal impeller version either. The pumps from jaguar/with the jaguar part number AJ88912 seem to be ~£180!! Whereas the Airtex versions seem to be around £30.

My understanding is that the recommended water pump was:
1. White impeller
2. Metal impeller
3. Black impeller

But I am just wondering if there has been some update to the water pump design that has resulted in a new and improved black impeller design. The plastic does seem quite brittle compared to the white impeller version I took off.

Wish I hadn't touched the bloody thing now, the old impeller looked fine but I buggered up the plastic mating face taking it off.

 

The black impeller being used now is not the same as the one that failed 20 years ago.

 

Hi BTF287,

Welcome to the Jaguar Forums. It's great to have you with us!

As RJ alluded, the old black plastic impellers were made of Nylon 66 and it is highly unlikely that any water pump manufacturer is still using that material given its high failure rate. The revised plastic impellers were made of black or white Poly Phenyl Sulfide, which proved to be much more durable. Since Airtex is an Original Equipment Manufacturer for Ford and Jaguar (among others), your Airtex pump is probably the one Jaguar is currently supplying as a replacement. The color of the plastic is irrelevant. What matters is that you really want plastic and not metal. The Organic Acid Technology coolant (DexCool) used in X308s and later Jaguars offers poor protection for metal impellers against electrolysis and cavitation erosion, which is why most other manufacturers who use DexCool also use plastic impellers.

Here are a couple of relevant Technical Service Bulletins:

TSB 100-16 Introduction to Extended Life Coolant

TSB 303-60 Coolant Pumps - Identifying Impeller Material

When you get a chance, please visit the New Member Area - Intro a MUST and post an introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Cheers guys that is great news! And thanks Don B for the extra information, that is interesting!

I will post in the new member area shortly.