I just replaced mine with an AC Delco water pump, mainly because that's what someone on here recommended. No problem with it, but I'm pretty certain the casing is two pieces. I'm also waiting for my new aluminum thermostat tower assembly - whatever it's called. Mine is weeping coolant and I'll be glad to stop that aroma from wafting around my cabin.

 

Hmm, to my knowledge, there is no aluminum upgraded assembly for the later 4.2L engine...

 

^^ That is what I thought as well. If there is indeed one available now for the 4.2, then please spread the word where it can be purchased. If and when I must do this repair again to my wife's 2006 XK8, I would certainly try it next....

 

Well, I hope these bozos aren't lying to me -

https://www.ebay.com/itm/For-Jaguar-...53.m2749.l2649

I hope that link works. It says it will fit a 2006 XK8.

 

Okay, they were lying to me. If anybody needs an aluminum thermos housing for a '98 to '03, let me know soon, I'll give you a good deal. Otherwise, I'll have to return it. I guess it's plastic for me. This has happened to me before, I should know better, but ...

 

The spike in the temp reading could be as simple as low coolant - if you have an air pocket near the thermostat it could cause a temporary reading. Never had that happen on my car but past vehicles, yes.

As for the aluminum "upgraded" thermostat housing, I've only heard negatives about that. While it seemed like a good idea in theory, mechanics have said the parts never lined up correctly and when heated they leaked. YMMV.

 

New pump came in and it is indeed a single piece casting with a metal impeller. I like the gasket better as well; previous one was stamped metal with the new having an oring around the center and rubber around the end seals.