D4 Coolant Level Sensor

[mijango]

I recently had my mechanic advise that the Coolant Level Sensor is faulty and I get a message as such on the dashboard display. He said he could replace it but it’s not essential so I held off given I had other servicing costs.

So question : is this an easy DIY replacement? (the error message is becoming disconcerting)
If so, what’s involved and any recommendations on where to source?
TIA!

[BradC]

I'll just say the coolant level sensor is the only way you're going to know you've had a catastrophic coolant loss before you toast the motor. As the coolant temp sensor sits in the water, once the water is gone it takes a long time to register the increase. In the mean time bad things happen.

In the D3 we replaced the coolant bottle as a whole unit.

[Ean Austral]

On the D3 , The float gets coolant logged and sinks tripping the warning . Easy to replace the whole bottle , so would assume the D4 suffers the same issue .

roverlord sells a good priced replacement.

Cheers Ean

[PerthDisco]

On the D3 , The float gets coolant logged and sinks tripping the warning . Easy to replace the whole bottle , so would assume the D4 suffers the same issue .

roverlord sells a good priced replacement.

Cheers Ean

Interesting, I have seen this reported many times but not had the problem (yet) MY08. Same supplier as the dodgy big end bearings perhaps.

[DiscoJeffster]

I bought a generic replacement bottle and it came with a faulty sensor of all things. In the end I replaced the new aftermarket sensor with my original one. No issues since. I only replaced the bottle as I was doing a coolant flush

[DazzaTD5]

D3 / D4, both can have the same issue.

*The sensor can fail if its newer.
*Older as previously mentioned, the float gets coolant logged and sits on the bottom of the expansion tank.

I recommend getting it replaced, as others have said.

[Plane Fixer]

I had a coolant low warning come up whilst driving on the highway. I pulled over very quickly and shut down. When I lifted the bonnet the level was normal, what a relief.
Overflow bottle replaced which also gave me the excuse to clean out the intake manifold and replace the plastic coolant manifold as well.

[mijango]

Thanks to all.. I’ll look to purchase a new coolant bottle

[kenl]

I was getting the low coolant level after changing/flushing my coolant, the messages were every time i drove the car despite the levels being correct.

There is a video (on the net) showing that the float will sink in water or float in coolant, suggesting that the float is in fact a hydrometer as well as a level warning.

Anyhow, when refilling mine after many flush cycles I only put in 5 liters of coolant concentrate then about 3 liters of water, that was it, even after bleeding it was full.

With a system capacity of 11.8 liters I needed 5.9 liters of coolant concentrate to get the correct mixture. By sucking out 1 liter and replacing it with concentrate the low coolant warnings are gone, for last week at least. If you were refilling with premix you would have no hope as the system does not fully drain, at least not when draining as per the workshop manual.

[DazzaTD5]

If that was the case, replacing the expansion tank with a new one would make no difference to the low coolant warning. Yet after replacing 50 million of them I've not had this issue return.

I use premix from the oil supplier as I believe their mix is going to be more accurate than trying to mix it in the vehicle.
Also I know there are workshops out there that simply use water to mix which negates any spec coolant has.
Too weak or too concentrate and coolant is corrosive.
Draining and refilling every 2 years or so will keep it at a good mix.
Using a accurate hydrometer is the only real way to check.

[kenl]

Fair enough, I was merely saying that I fixed my problem, considering that the level sensor was fine before flushing, but not afterwards.

If ones not flushing the system it probably wouldn't be matter, I couldn't locally source the specified coolant so thought a full flush would be the way to go as mixing coolants is also not a good idea.

Personally i took a risk on calculating a 50 50 mix of coolant and (de-mineralised) water as per the manual.

[DiscoDB]

Fair enough, I was merely saying that I fixed my problem, considering that the level sensor was fine before flushing, but not afterwards.

If ones not flushing the system it probably wouldn't be matter, I couldn't locally source the specified coolant so thought a full flush would be the way to go as mixing coolants is also not a good idea.

Personally i took a risk on calculating a 50 50 mix of coolant and (de-mineralised) water as per the manual.

I suspect you will find this only buys you some time before eventually the float has absorbed enough coolant and ends up stuck on the bottom no matter what you do. It seems to loose its "float-ability" over time and eventually gets stuck. At least this is how mine failed over a period of 1 year (started as intermittent getting stuck and then returned to normal - before eventually stayed at the bottom).

Now to replace the bottle and discovered my hands are not small enough to get to the bottom hose clamps.....grrrr.....

[sharmy]

I need to change the expansion tank on my sons 2005 d3. Are the cheep after market ones ok or do they split like the d2 ones. On one of the UK parts sites, they state the oe d3 comes without a sensor or bleed screw but the d4 does. Are the sensors the same with the same connectors.
John

[DiscoDB]

Part LR020367 suits both the D3/D4 and RRS. You should be able to order complete with new sensor and bleed screw. You reuse old cap.

I bought mine from British Auto Parts in Bayswater, Victoria - dispatched in mail same day.

The bottle looks identical to the one shown in the Atlantic British video on how to fit, and the same as sold by LR Direct in the UK.

I have yet to fit but the quality looks good. On the online ad it says “this is not the cheap Britpart one”.

[PerthDisco]

I’ve read a lot you should ideally change the cap at same time and not reuse old one.

[DiscoJeffster]

Don’t buy this

Expansion Tank - LR020367P - Aftermarket | Rimmer Bros (https://rimmerbros.com/Item--i-LR020367P)


It had a faulty sensor when it arrived and the bleed screw has leaked from day 1. I’m not sure who actually manufacturers it - “Aftermarket”

[sharmy]

Thanks for the info,I also noticed his inner front cv boot has split around the shaft. Has anyone had success fitting a universal split type where you use glue to join them, I recall they used to have a tongue and groove type of join.
John

[PerthDisco]

Thanks for the info,I also noticed his inner front cv boot has split around the shaft. Has anyone had success fitting a universal split type where you use glue to join them, I recall they used to have a tongue and groove type of join.
John

I successfully used the YouTube bike tube and cable tie interim solution.

Believe glad wrap can also be used as short term “bush trick” solution.

I then bought a genuine LR boot kit with new grease for not too much online.

How to here;

DISCO3.CO.UK - View topic - How To? - Change Front Driveshaft Boots (https://www.disco3.co.uk/forum/topic54694.html)

[DiscoDB]

Don’t buy this

Expansion Tank - LR020367P - Aftermarket | Rimmer Bros (https://rimmerbros.com/Item--i-LR020367P)


It had a faulty sensor when it arrived and the bleed screw has leaked from day 1. I’m not sure who actually manufacturers it - “Aftermarket”

Aha - that looks like the cheap Britpart one......