coolant level low warning

[atticus]

Thanks, Allan. That is very helpful - even I should be able to manage that.

I had gained the impression that the tank only needed changing if it was split and leaking and didn’t appreciated that the float is part of the tank assembly. I guess the float must be a collar around the tube that holds the sensor and that it has a magnet in it which activates the sensor as the coolant level drops. This would also explains why the sensor is just a click fit yet doesn’t leak!

It sounds as though I should have bought the whole tank assembly and not just the sensor.

[andypryce]

Sounds like the float is sticking, may just need a bit of loosening and lubrication? Not sure how accessible it is though?

[Andy P]

Hi atticus,
I agree with andypryce,worth trying to clean the float mechanism.
Just suck the coolant out of the tank and you should be able to see the float.
A little lubricant spray and then gently move the float up and down.
Hope that helps and good luck.
Andy

[atticus]

Thanks Both.

I ordered the new tank as soon as I realised, with your input, that the float is inside the tank. When I started the car with the new sensor in it was fine until the coolant heated up then the warning light came on, so it appears that it starts off floating then sinks!

When I get the old tank out I will explore and report back.

[ianfullick434]

My 1999 XK8 has also had this low coolant level warning when the coolant level is good, but within a few seconds it goes off. My mechanic thinks it is the level sensor and just needs the level to be monitored.

[atticus]

Apologies for the delay in wrapping this up. So, the new Jaguar branded header tank (with sensor) from Barratt's did the job (part No. MJD4400BA). It is quite an easy task, but best to get the specialist tool to open the hose clips that are fitted (what's wrong with good old fashioned Jubilee clips that only need a screwdriver or a small spanner to loosen and tighten?). I have the old tank out and the collar that forms the float does go up and down freely, so I am not really sure what the problem was, I am afraid. Anyway all done and well within the capabilities of the unhandy.

[mike020150]

All's well that ends well. There are still some jobs that can be completed successfully by a competent DIY mechanic. Mike.