How much are the coolant tanks?

Mine was about 30 Euro from the Dutch dealer. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Not too expensive from memory... PM Dan for an accurate price, but im sure its less than £50

Many thanks for your technical advice Craig, I'll swap this out too when I do the radiator at the end of the month. Also tempted to leave the viscous fan off over the winter and see how that goes... .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

What's the problem with the tanks then? Do they leak or something?

Tanks can crack and then leak - mine did, same on earlier Disco. Easy fix.

On the o.p. problem, may be useful to take a look here:
http://www.rangerovers.net/rrmkiiiremedies.html#coolant

Also confirms as several have said above that you get this problem if the mixture is wrong, or the sensor thinks it is. Norman

Current LR: L405 Vogue TDV6 (MY 2014) Aintree Green/ Ivory interior
Past LR: L322 Vogue 4.4 V8 (2002); Discovery series1 V8 (1995)

Nice find normanp

here is the content

Quote:

Cooling System

Low Coolant Light On: Some examples of the Mk III RR have been reported to exhibit strange behaviour of the coolant level warnings. Bernard Green experienced the problem of constant reminders that the Coolant Level and W/S/Washer water levels are LOW........his local dealer have said that it is the same system as BMW and that does the same thing "just keep putting a pint or so in it and it will be OK".......He wonders why they have bothered fitting such a large reservoir and how inconvenient in the Kalahari Desert!!! Another owner reported that within the first 200 miles of service the low coolant light went on. Jimmy Fang the low coolant signal shortly after the 15,000 mile service. He was in Charleston, and took it to the dealership there and they topped off the fluids. Same light came home 2 days later on the trip home. Jimmy took it into the local dealership and they said the Charleston dealership must not have topped it off very well b/c they had to refill it. He now has 37,000 miles onm the vehicle and has not had the problem again since.

Paul Levens reports he had similar problems with the BMW 540i he had previously, which seemed to have a very sensitive coolant level sensor (most likely the same one used on the new RR?) which generated several false "check coolant" warnings.

According to official Land Rover Technical Service Bulletins issued in September 2003 and March 2005, the low coolant light coming on even when the coolant level is correct if the coolant specific gravity or viscosity is incorrect, causing false readings on the sensor. The correct specific gravity of a 50% coolant mixture of the approved coolants (see below) is 1.07.

Note also that earlier models had Texaco AFC coolant, LRN6024 (orange), while later ones come with BASF G48 coolant (blue). Note that these should not be mixed -- or premature corrosion of the cylinder heads could result.

Radiator Leaks: Sometimes, the problem is due to an actual radiator leak. Nicholas Tan reports his RR had about 15,000 miles on it when he started experiencing recurrent "low coolant" warnings. The cause turned out to be a leaking radiator, but the dealer found that the coolant loss only occured between certain pressure limits, so it was a slow loss over the period of about a week. In December 2005 Andrew Elmore reported his 2004 model had the check coolant light coming on frequently, each time needing at least one quart of coolant to top off the tank. "Even though it is winter here the problem seems to be getting worse, that is, more frequent. I called the dealer last week and the service manager said, "oh, that type of coolant evaporates, so don't worry about it," but I do not think a quart of coolant in a closed system can evaporate in the winter in less than a week". Andrew persisted in posing the problem to the dealer, and at last they replaced the radiator, which they said had a "small leak at the seam." Alex Johnson had a leaking radiator twice on his 2003 RR, the second time conveniently 13 months after the first so he had to pay for the replacement.

Summary: Thus it seems like in some cases there is a coolant sensor problem leading to a false "Check Coolant Level" message; in other cases there is a genuine leak in the radiator or elsewhere in the system -- usually the coolant overflow tank (see "radiator leaks and overflow tank leaks" below). In yet other cases (the only ones officially recognized by Land Rover) it is all your fault for putting in the wrong coolant mixture!

I can understand it if coolant was low (due to my leak in the rad) but not when coolant level is correct, Perhaps it is a pressure thing too, and/or the coolant sensor being defective? .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Changed out my coolant tank today. nothing wrong with the tank itself, and I can now see you can simply change the sensor, part number PCJ000020, Now have a spare tank  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

^ Can you do a brief post on "How To" replace the sensor?

No problem, coming soon... .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

These things are great for the WIKI and search

Done

http://www.fullfatrr.com/forum/topic20913.html .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Have applied a SOLVED to the OP.

After a week of running with my new coolant tank and sensor, new EGR thermal valve and new radiator and removing the viscous fan can report, no leaks or coolant loss, no temperature drop downhill (although it may not have been cold enough for that yet), and engine warm up time down to 4 miles in the morning - was 10 (cold after overnight start) and @ 2 miles in the evening - was 7 (cold start).

Given the warm week, was expecting to see temperature rise past normal without the viscous fan, but even in traffic holds steady, and no sign of the A/C fans kicking in (assuming they work!). .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999