I had a cracked return line nipple on the overflow bottle on the XF (2010). I ordered a new aftermarket bottle, installed it (much gnashing of teeth and cursing while trying to find the retainer clip that I dropped), filled the system with water, and sent the wife to driving it.

Two weeks later, she reports a "low coolant" message. I can see a drip coming from above the lower hose but below the return line. I see by reading elsewhere that aftermarket bottles often have a cracked-seam problem. What can I do?

Also, there seem to be two chambers in the bottle. One (directly under the return line) is completely full, while the other (the "main" chamber) is losing coolant. Is this normal? Also, there's some little plug screw right above the return line. Should it be tight, or is it a pressure relief plug or something?

Sorry to sound so obtuse.

J.D.

 

J.D.,

I see this question as correctly belonging in X250 forum where members with the same model are more likely to see it but will leave it here for a while.

Is this a N/A or S/C engine? According to JEPC they use different Expansion Tanks.

NATURALLY ASPIRATED


SUPERCHARGED


Graham

 

So why not buy the genuine part ?

 

Ditto

 

It's a normally aspirated engine. I dropped the question in this forum because I had a similar problem on my S-Type (I replaced that bottle, too, right before I sold it).

I bought the aftermarket part because, at the time, I was a little tight on money. The genuine part was $125, and the aftermarket one was $45. It's an overflow bottle, for Pete's sake, what could possibly go wrong? Well, we now see, don't we?

 

The small one in the top that looks similar to a radiator drain plug? As it's at the highest point, I'd expect it's to bleed air and should be tightened afterwards.

Graham

 

Well, no it's not an overflow bottle, it is the reservoir and highest point of the cooling system, and takes the pressure cap that maintains pressure in the coolant circuit when the coolant has warmed-up. So it has to hold the coolant under pressure, about 10 lbs/sq inch. Even when cold the tank will contain coolant and there is a level indicator to show the correct level, and a level detector too. I sympathise with you about the cost of the part, Jaguar charge far too much for their parts as I know, as a couple of years ago I had to have a header tank replaced for my X350 (XJ6) saloon, plus a water rail too. I bit the bullet on that one with Jaguar parts.