Changing the coolant in my 2008 XJ8 running into problems
bought a new reservoir everything is replaced but it keeps leaking coolant from somewhere
anyone run into this problem
really struggling to find where it could be coming from

help is greatly appreciated

 

Is the reservoir the only thing you changed? And did you change it because you already had a coolant leak?

Check the usual places for coolant leak:
Reservoir cap not seated correctly or cracked
Reservoir bleed valve not closed properly
Thermostat housing - cracks etc
Water pump
Valley hose
Radiator - especially the top hose plastic connection as they can crack and leak

There are other areas that coolant can leak from so I would check all coolant hoses and connections.

 

If you are not familiar with the radiator pressure tester kit, google it. You can source it inexpensively either online or Harbor Freight. If I suspect a coolant leak, I use it and within seconds I can figure our where the leak is. Now, if it ends up being the valley hose then it may take a little longer.

 

Two questions about the reservoir on this XJ8.

1) What is the plastic screw on top of the coolant reservoir for? Does it always need to be down tight

2) This is the second time I have had to replace the Coolant reservoir in two years. In both cases it leaks at The seam where the black plastic on top and the clear plastic on the bottom of the reservoir meet. The second time it was right after I refilled it with coolant after changing it and driving it for the first time

 

1 That is for venting air as new coolant is added. When you are sure you have all the air out the plastic screw should be inserted and tightened.
2. I have replaced 2 in the past 5 years and both are still in service. I used genuine Jaguar parts.

 

Follow the procedure for correctly bleeding air from the cooling system or excessive heat and pressure are the result that can lead to reservoir failure.

If you don't have the workshop manual, here is a link:

https://www.dropbox.com/s/xl1qtf4hwt...anual.pdf?dl=0

Refer to page 2290 for the bleeding procedure.