Low coolant level warning has been popping up intermittently recently. Given that it is intermittent, I assume it is more likely to be the sensor unit rather than the magnetic float, as the latter would either sink or swim permanently?
So a simple case of ordering a new sensor, withdrawing the old one from the reservoir pocket and slipping in the new one. But it's a Range Rover, so it won't be simple. Or will it?
Advice and moral support appreciated. 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

Easier to fit a new coolant bottle and not disturb the seal between sensor and bottle.
Path of least resistance  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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Thanks Dr Rob, but as I understand it the sensor slips into a pocket in the reservoir and does not actually come into contact with the fluid, so there is no actual seal required? 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

PS When is your Defender arriving?? 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

I had the same, but now it's always there as a fault on start up.
Bought a new reservoir 2 months ago.

Might be time to fit it one of these days when I'm not too busy procrastinating

I had this problem and replaced the sensor. Two days later I got the same low coolant message.

The sensor is optical and reads the coolant level through the reservoir bottle. Eventually the bottle becomes dirty and/or opaque enough to affect the readings. You could remove the bottle and try cleaning it with suitable solvent or buy a new replacement. 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Same thing, I replaced with a genuine part which was around £60 with the VAT:

https://www.island-4x4.co.uk/expansion-tan...28649.html

You can get much cheaper but for the sake of £30 or whatever the difference was I figured a genuine part was best option.

Never had an issue since changing it. Just got to bled it out etc.

Jon

Mulcher wrote:

I had this problem and replaced the sensor. Two days later I got the same low coolant message.

The sensor is optical and reads the coolant level through the reservoir bottle. Eventually the bottle becomes dirty and/or opaque enough to affect the readings. You could remove the bottle and try cleaning it with suitable solvent or buy a new replacement.

Hi y'all,
any hints or guidelines on how to replace that damn bottle ?
I've had the same warnings and the same full enough coolant level...
SO I ordered a new one, but now I'm wondering if any of you gents might share some pointer on the "How to" part ?
Chhers "it needs some intelligence to undestand you may not have enough"

Here I found it,


thanks all "it needs some intelligence to undestand you may not have enough"

Can anyone tell me if it is possible to replace the sensor without removing the reservoir? I'm thinking remove air filter box, loosen reservoir securing bolts, and wiggle it to an angle with hoses still attached to enable enough clearance to swap sensor. Do-able?? 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

It is possible to replace the sensor, but it isn't the part at fault here (or rarely). it's the floater inside the bottle that is the culprit. Due to aging, it doesn't move freely enough to enable the sensor to capture the correct info, hence the faulty warning. I guess you could rince & clean the bottle but many tried and the cursed warning reappeared eventually. Watch the video and you will see the (culprit) moving part inside the bottle ... I will replace mine soon when I have a couple hours of free time.

Cheers
Sylvain "it needs some intelligence to undestand you may not have enough"

Thanks chaps, new bottle it is. 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

New expansion tank fitted yesterday. Video was very helpful, but just a few tips for other amateur diy-ers like me attempting this:

1) I syphoned out the coolant into a clean container for reuse. This minimised losses and made the tank easier to handle.
2) In the video, he nonchalantly lifts out the airbox base housing. I needed to use a piece of 2x1 timber to lever it out from the side grommets - it was very tight.
3) The lower hose connection slides into a keyway on the tank connection, so don't try twisting it off as I did.
Push - pull action only.
4) The new tank base lugs were a tight fit in the locating sockets. A squirt of silicone spray helped ease them into position.
5) Finally, don't pick the hottest day of the year to do the job! 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

For those with an inquisitive mind, this is the coolant float sensor within the tank. A ring magnet within the float activates the reed switch. Buoyancy test revealed a complete lack of buoyancy, hence the false alerts.

Click image to enlarge