Hello all, something I noticed on my '02 XK8 while getting to my heater pump: on the top of the expansion tank there are two bleed lines, one goes to the thermostat housing and the other goes to the top LH side of the radiator in the back. When I removed the lines from the expansion tank the nipple for the back of the radiator line was plugged! Yet there is a line installed going to the back of the radiator. Any idea of what's going on with this? It's just a solid nipple.

Thanks as always.

 

Jaguar determined that it wasn't needed, so replacement tanks are plugged. Whoever put the tank in realized it was easier to connect to the blanked port than to plug the radiator fitting.

 

Well noted and thank you.

 

This excellent Jaguar document that should clear this up. And yes, this is a thing: 2 different arrangements, 2 different parts, and a way to retrofit the new part to the old setup. Hope this helps.

 

This presents an opportunity for overheating on 1997 cars. If the coolant reservoir is replaced with the 1998 onwards version and the hoses are connected as they were originally, the airflow between the coolant tower and the reservoir will be curtailed.

 

Barnter ...that would only be true if you got the lines reversed on a later expansion tank.

 

? - the lines should be swopped at the tank:


97 plumbing




98 plumbing

 

To clarify ..the one from the top of the rad should go to the blanked off expansion tank connector . Or just drill lit through.
If you remove the pressure cap when cold and start the engine you can see the water circulation if its ok.

 

That's precisely why I posted this. The 1997 xk8 I'm restoring had the newer expansion tank with the hoses connected incorrectly. The tank showed signs of overheating. Given that many owners might be unaware of the changes when replacing the tank, how often does this occur?

 

I'm afraid I can't answer you question on statistics, and it would make more sense to me had Jaguar specified that the frontmost port on the superseded CET should be the blanked one - no plumbing changes necessary then.

It's likely the supersession considerations took some account of the radiator bleed deletion: another 5 minutes thought would have scored 100%.

IMO plugging the radiator outlet would have been better, given how fragile the bleed hoses become after years baking on the top of the motor.

Just my

 

Michael, I am discovering that I have the same problem on my 1997 XK8, Can you tell me which what is better ie swapping the 2 lines compared to drilling the blanked off line as someone had suggested earlier? Thanks

 

Hi firouz and welcome to the forum.

The easiest thing to do is to swop the pipes over on the coolant reservoir, as noted in the document, since that requires no engineering.

If I were faced with this, I'd follow the route RJ237 hinted at and plug the radiator nipple, which is what member sklimii did:


That would allow the 'spare' bleed pipe to be discarded (one part less to fail!).

 

Thanks Michael. Let me try that.