W209: Check coolant

[IanW]

Lately, I've been getting intermittent 'Check coolant' messages. I definitely do not have a coolant leak - no change in level in the last 7 years, so I'm assuming that I have a faulty coolant level sensor.

I've found the part on WIS, but before I start dismantling things, am I going to lose coolant from the expansion tank? WIS doesn't make it clear whether removing the sensor leaves a big hole in the tank or not.

If I do need to buy M-B coolant, then I'll go the whole hog and change all of it, it's been in there for a decade.

Thanks,
Ian.

 

[BlackC55]

Just twist it 90 degrees. No coolant will be lost.

 

[IanW]

Good, sounds idiot proof....

Thanks,
Ian.

 

[IanW]

And indeed it was idiot proof.

For reference, the new part is A220 545 00 24, costs £14+vat from the dealer, and takes 5 minutes to fit. A suitably sized pair of pliers were required to encourage the old unit out.

Ian.

 

[alf1956]

Hello there, I am having the same problem with the low coolant visit workshop coming on all the time but the level is ok so I am thinking that the sensor is faulty, can you explain to me where the sensor is & how to change it please? I am getting the same thing on the screen washer bottle so I am wondering if the sensor has also gone for that?

 

[alf1956]

sensor changed but still getting message on dash ?

Hello fellow members.
I bought a new coolant level sensor from the dealers £15 & changed it which was a simple job as described but I am still getting the "check coolant level" message on the dash??? I also get check the level for the windscreen washer level message as well. does anybody have any ideas on what is causin this please?

 

[alf1956]

Bought a new windscreen washer sensor & fitted it as a lot of posts suggest that the coolant level sensor & windscreen sensor work in tandem but I am still getting the warning messages stating that the levels are low etc !