Coolant Leak - Water Rail Gasket (I think)
 

Hi,

I have a 2002 x-type 2.5L with a relatively slow coolant leak where the thermostat housing mounts, I think it is called the water rail? I attached a couple pictures (at least I hope I did) showing the leak, one with UV illumination to light up the leak-detection dye I added. The pictures are shot from the floor, looking up towards the water pump. Has anyone changed this gasket? Should I change the thermostat housing and upper radiator hose assembly while I am at it, or is it lots easier to do just the failing gasket?

Thanks,
Tim

I've not replaced this gasket, but recommend replacing the whole hose/thermostat assembly, part number C2S43430. SNG Barratt sells them on eBay for $99.99 with free shipping.
Jaguar X-Type V6 Upper Top Radiator Hose With Thermostat 2002-2009 C2S43430 | eBay

+1 on swingwing's recommendation. I recently replaced my upper radiator hose assembly (from SNG Barrett). During the installation I disassembled the the flange in your photo for ease of installation. There is not a gasket, it is an O-ring if it is leaking then the material of the housing has been eaten away and replacing the O-ring will not solve your problem.

Thank you for the great photos.

I like photos, everybody likes photos! (especially how-to or how-I-did-it ones)

I bought a big, powerful portable UV lamp to trace down some (real) cat pee once, and had never even once thought of using it to find my "mystery leak" with the Big Kitty, and now I feel like a dope.

https://cimg3.ibsrv.net/gimg/www.jag...023d9b2631.jpg


$5 for the UV juice, and I know the problem will be found and solved for sure now.

Wow, and thank you again!

Thanks for the advice
 

Thanks for the quick responses, especially during the holidays. I see the wisdom now in changing the whole assembly. I poked around this forum and youtube, looking for folks who did the whole job, seems like 5 hours of fun is involved for the average DIY'er. A local Jaguar specialty shop (Jag Tech's) quoted $478 including parts and new coolant, so I decided to give them a shot. I just dropped it off on my lunch hour, I'll do a followup post to let you know how it turns out. Thanks again, Tim