Hi folks,

As the title says, I was getting a low coolant warning despite a full bottle. I swapped out the bottle for a new one, but I've just had the fault re-occur. Bottle remains full.

Is there another common cause or fault to look at?

Many thanks

MW Car history includes: LR Series 3, RR Classic x 4, LR 101, Discovery 1 and 2, FFRR. D3, Freelander 2 and now back in FFRR.
Yes I'm a masochist....

Mine has started doing this 3 days ago, coolant level full, comes on occasionally and goes off after a short while, I assume it's the thin wire from the sensor has a break in it, will have to look at it in the next couple of weeks when the beast comes in for a full service and summer check.

Are you sure the coolant ratio strength is strong enough because I've read that the floats boyancy is effected if it's too weak.

As kevinp just said - there may be (I have a 4.4 petrol but not yet checked as its still new to me) a level sensor that is fed into the bottom of the tank.

It provides 1 function only. It floats depending on the specific gravity of the coolant/water mix in the tank.


That means if it is full to the brim with just water it will not 'float' and generate a low coolant message.

If it is filled with the required level of coolant and water ratio (50/50 I think) it will float according to the level of said coolant in the tank Current: 2003 TD6 HSE
2004 Vogue SE 4.4
Previous: 1993 Classic 3.9

Interesting, I have filled the system recently with a 40% mixture, I did 450 miles yesterday (virtually all motorway) and the message popped up right at the beginning of the journey and disappeared after a couple of minutes not seen it on the rest of the trip.
I'll remove some coolant mix and add some neat, that will over time increase the ratio.
Thanks for the suggestion.
Will

so far so good then. I need to re-explain though as my explanation was not totally accurate:

Inside the tank is a 'float' Its buoyancy is determined by the level plus specific gravity of the coolant mix.

Inserted via the bottom of the tank is a sensor. It doesn't go inside the tank but in a tunnel moulded into the tank. Inside the tank the 'float' (I think) is circular and fits around the tunnel that the sensor is fitted to.

If the specific gravity and or water level drops the float which contains possibly ferrous material will come close to the external sensor which I believe acts like a reed switch and closes the electrical circuit triggering the low coolant warning.

I stand to be corrected on this of course as I have not opened up a tank to verify.

On my tank the sensor was o.k. but the float had become less buoyant and would trigger low coolant if the engine was revved hard. I think what was happening was the float had become covered in rust and other grime and was less buoyant, revving the engine caused possibly the level to slightly drop quickly dragging the float down lower than the actual level momentarily.

Phhewww I think Ive talked this one to death so will stop here! Current: 2003 TD6 HSE
2004 Vogue SE 4.4
Previous: 1993 Classic 3.9