A couple of weeks ago our Sport when in for some warranty work and it received a software upgrade. When I picked it up, it displayed the "Low Coolant" message when I started it for the first time. I assumed this was a gremlin and had been introduced when getting the software upgrade, as I had read so much about this error message on these forums. Therefore, I've ignored it.

However on closer examination the other day, the water level is actually too low. I've only realised this three weeks later!! Reading the correct level is rather tricky and I needed a torch to shine light through the rear of the chamber. Sourcing the correct anti-freeze has proved difficult too (should be Castrol SF) so I purchased 1ltr bottle from the LR dealer. Cost £6.57+VAT.

So, the moral of the story…..just maybe the warning messages are correct! Matt
-------------------------------------------
RRS ownership for 1 yr, then D3 for 2 yrs. Then cut back to old bangers and working my way back up through two Peugeots in 6 months. Now got Saab 9-5 2.3t and enjoying the performance!

Mine comes on/off all the time too, apparently they replaced the sensor as it was faulty, but it kept coming on.. mine might be telling the truth too then! will check it when i get my car back.. Past: Bmw M3 Coupe 57, 335d Coupe 56, Audi RS4 06, RR Sport TD HSE 05,
Current: 57 Bmw 730d Sport, 56 Merc S320 CDI L, 57 Merc Viano L 2.2CDI

WWW.MHCFINANCE.CO.UK
Kam@Mhasnain.co.uk : 0121-622-1369

Featured in: WWW.STREETCREDMAGAZINE.COM, www.police-information.com

Just found this thread after posting a new one! Looks like I have the same problem Matt! A Carbon Footprint is the mark a lump of coal makes when it's dropped on the ground.

Tata TDv8 HSE - Stornoway/ebony and straight grain walnut with towpack, Tasmods and an HST grille. Coming soon LEDs in the headlights
Staying - Epsom Green Defender 90 for playing off road

I've had the same problems. Had the glitch and had the the tank replaced. Started getting the warnings again and thought nothing of it. While at the dealer today i mentioned it, and it actually was low. The pressure tested it, but found no leaks.

As mentioned elsewhere recently - I too have just had a few Low Coolant warning messages.

SO

Went to dealer today - they looked at it - now booked in for next week to have a NEW one fitted.  
" WITH MORE EXTRAS THAN A HOLLYWOOD EPIC "

Mine was very low so don't ignore the warnings! For the last week I been adding Coolant/ Antifreeze and water in a 50/50 mix to refill back to minimum.
Left the car in the airport carpark last Sunday to come south and when I returned yesterday the 1st thing I did was pop open the bonnet and check the level....................... nothing more appears to have been lost. The only conclusion that I have come to is that when they car was serviced they dropped out the coolant and refilled the reservoir until it reached the minimum mark and somehow got an "airlock" in the system. Driving round for a week has forced the air round the system back to the reservoir making it appear to be loosing coolant. In the last 2 days the level has not changed so I assume that now all the air has worked it's way out of the system. As the dealer had the car for a whole week to do the FBH fitting and service you would have thought the staff would have run the engine a bit (they did for something as they used neigh on 1/4 tank of diesel at the service and hardly put any miles on the car!) to make sure that all the air was out of the system before handing it back to me with a Low Coolant alarm! A Carbon Footprint is the mark a lump of coal makes when it's dropped on the ground.

Tata TDv8 HSE - Stornoway/ebony and straight grain walnut with towpack, Tasmods and an HST grille. Coming soon LEDs in the headlights
Staying - Epsom Green Defender 90 for playing off road

This has now happened to me too. Had the RRS's first service - 2 weeks later Low Coolant warning comes on! RRS 2.7 TDV6 HSE Zambezi silver,Alpaca.
On Order - LRX expected 2010
DO NOT CLICK HERE!

Mine flashed up the message for the first time in the LR dealers car park when collecting the car after the first service.
Check the levels. Mine was low. You would of thought that a service would include this check. Matt
-------------------------------------------
RRS ownership for 1 yr, then D3 for 2 yrs. Then cut back to old bangers and working my way back up through two Peugeots in 6 months. Now got Saab 9-5 2.3t and enjoying the performance!

Just checked - plenty of coolant. Another warranty job I feel! RRS 2.7 TDV6 HSE Zambezi silver,Alpaca.
On Order - LRX expected 2010
DO NOT CLICK HERE!

There's a brand new (June 12) Tech Bulletin out for this. I had the same issue. Here you go fellas:

TB# LS303-006

SECTION: 303-03
"Low Coolant Level" Message or Warning Lamp Illuminated
AFFECTED VEHICLE RANGE:
Range Rover Sport (LS) VIN: 6A900129 to 6A929342
CONDITION SUMMARY:
"LOW COOLANT LEVEL" MESSAGE OR WARNING LAMP ILLUMINATED
Situation: A customer may report that the "Low Coolant" amber warning lamp is illuminated or a "Low Coolant Level" message is displayed in the Message Center when the engine coolant expansion tank volume is within recommended levels.
The coolant level float in the expansion tank can absorb coolant causing the float to sink. The warning lamp and message will display when the float sinks below the low level sensor trigger point.
Action: Should a customer express a concern related to the above condition, within the specified VIN range, refer to the Repair Procedure detailed in this bulletin.
PARTS:
NOTE: The current expansion tank part PCF500015 may be used only if the sticker on the side of the part has a date of 31-10-05 (DD-MM-YY) or later. A newer part PCF500090 may be used when available.
PCF500015..............Coolant expansion tank (dated 31-10-05 or later) Qty 1
PCF500090..............Coolant expansion tank Qty 1 

Umbertob - thanks for that but my VIN is a 5A****** but probably the same cure. RRS 2.7 TDV6 HSE Zambezi silver,Alpaca.
On Order - LRX expected 2010
DO NOT CLICK HERE!

When it comes to RR Sport I have never seen a tech bulletin from Land Rover referring to 05 VINs when indicating a range of early builds, yet they obviously built some and they surely share the same parts (and problems) as 06s... I wonder why that is  

My 05 LR3 had the same problem with the faulty sensor. The dealer changed it out. 2006 RRS Silver/Black

So did my RRS until they fitted the FBH and then it really did loose the coolant for a week afterward, very alarming! Turned out not to be the float or a leak, it was air in the system being pumped round. I must admit I wrote a screed on the "how did you rate our service" letter that came from LR and the dealer about it............. why when they had the car for a week and used 1/4 tank of fuel did they return it with less coolant than it needed??
BTW my RRS is only about 20 or so VIN's from VA's A Carbon Footprint is the mark a lump of coal makes when it's dropped on the ground.

Tata TDv8 HSE - Stornoway/ebony and straight grain walnut with towpack, Tasmods and an HST grille. Coming soon LEDs in the headlights
Staying - Epsom Green Defender 90 for playing off road

talked to my stealer today and he told me the most problems with the RRS is the low cooling warning.... they exchanged the expansion tanks 2006 RRS TDV6HSE java black/alpaca, Privacy, S/C Grille & Vents, debagded and rebagded, Stormers, Tasmod`s sills, RRSPORT umbrella and stickers
2008 Aston Martin V8 Vantage Roadster

PS: All my spelling errorz are copyrighted!!
Clicky!