Most likely, it's your water pump and not the coolant pipes. How many miles on your XJ and was the water pump ever replaced?

 

Check on YouTube:
Jaguar XJ, F-Type, F-Pace, XF, XE, Range Rover and LR Discovery with a 3.0 have the same engine. Search those on YT on how to replace cooland pipes.

 

Here are the aluminium pipes installed on an AJ126:

 

My XJ is a 2016 with 47k miles as of yesterday. No knowledge if the prior owner replaced the pump.

Where is a good place to order the pump? Or is it oem only?

 

If your interested in upgrading to the Aluminum cooling pipes there some kits that might be what your looking for?
Cooling System Upgrades

I have a couple of complaints with the above kit? For you 3.0 SC guys you can also get the rear water manifold in metal. Another VERY worthy upgrade! But the kit will get you the plastic version.
The water pump to oil cooler brick pipe also in Aluminum to replace the factory plastic version. Cheap at $15.
Al. Tube from WP to Oil Cooler Brick

Here is the rear water manifold in metal and it's a bit pricey so you need to decide if you want to upgrade that or not. Now with the cost of labor if your not doing this DIY I would think hard about adding that metal part. Everything will be apart at this point and almost no additional time required to swap that rear manifold out.
Al. Rear Water Manifold
.
.
.

 

I just did that job on a 3.0L 2014 Range Rover Sport, and I thought, while I am here with the supercharger off, I should just change that rear manifold. Boy that was a lot of extra work!!

 

It is but we have had several guys change it WITH the SC in place! I can't imagine even attempting that without removing the SC!
.
.
.

 

Me neither.

 

Are there any known write ups with pics or videos showing how to even attempt to change without removing the SC?

 

Step 1: Buy one of these

 

I've replaced the rear coolant pipe on the 3.0 without taking off the SC. It's definitely tight, if you have big hands, I don't think you'd be able to do it. You'll need a low profile ratchet like this .....

GEARWRENCH 35 Pc. Microdriver Set - 85035 https://a.co/d/9sXE1H1

Wipers, the the wiper shield will have to come off.
The wiring harness will get wiggled around some stuffz there is just enough slack.
Your back will hurt.
Your hands will get cut up.
It'll take about 4 hours.

I'm mad they didn't have the metal version 2 years ago!

 

I've seen videos on YT. Removing the SC is time consuming but fairly easy. Organize all the parts you removed so that it'll be less hastle when you install them back in.

 

Purchased these... and ready to install.

I want to know are they the "revamped" versions that fit properly?
https://www.ebay.com/itm/224893885947

 

They should fit perfectly well.
On another thread around here somewhere (there are multiple threads in multiple sub-forums covering several late JLR models about these alu pipes) EuroAmp have stated that they had a batch of poorly machined / defective pipes but those are all gone now and the latest/current pipes have no problems.

 

Only way to be certain is to ask EuroAmp.

 

Definitely reassuring. Thanks

 

Have had the plastic coolant pipes replaced on both 2015 F-Type & XJ with supercharged 8 banger with aluminum pipes with zero fit issues . Supercharger not removed on either installation .

 

While we're here, what brand water pump is recommended? I think I will do that as well. Since things will already be apart.

 

They have the rear crossover in metal for the V8? If so, link please.

 

Did they ever change the plastic pipes, etc. to metal in the later years 2018-2019...?