Hi,
Interestingly my W205 and W251 have popped up with the Top Up Coolant message this week.

We have seen a few 35°C (95°F) temps here in Sydney Australia the last few days.

My questions are:
1. are you simply topping up your Coolant? Or have you done a coolant flush as part of a major service?
2. Im not expecting this to be the case, but do the diesel mercs require a different coolant?
3. Should i be able to use the same coolant in both vehicles?

Thanks in advance.

 

Strange enough mine has two coolant reservoirs. I am not sure why. I never topped up coolant. Its a German built C200 AMG line with Gulf specs.

 

My new mechanic says the sensor is located near the top of the coolant overflow, so apparently its triggered when some evaporation has occured.

Supposedly, i can just add de-mineralised water (or cooled boiled water) to bring the level back up.

 

I believe there’s 2 on our vehicles
the overflow is the one closer to the middle of the car
Cap should not be tight on that one.
but don’t overfill
the dealer will do that and it will leak out all over

 

the older W205 had 2 coolant tanks, the 2nd one just over the turbo... while the 2017 and above would have a single coolant tank only.
Likewise the larger CC engines would also have 2 coolant tanks.

For coolant the W205 uses the coolant spec 325.5 (pink in color), part number A000 989 28 25 11.
Hope this helps.

 

yes, i check and top off frequently even if it's just a splash. I check concentration once a year to make sure it's all good. I replaced the cap recently as the old one was leaking a bit much for my liking when it was venting.. cap replaced and fits much tighter and less of a coolant smell when hot/

 

I've had to top off my coolant twice in 174,000 miles. Maybe 6-8 oz each time.

 

i got a message that said "Check coolant level"
i looked at the tank, it's really low.
i'm afraid to drive it, is it safe to drive to Mercedes dealer that is like 10 miles away to buy antifreeze/coolant ?

 

you can top up with distilled water (recommended), and in worst case scenario you can even use tap water if you cannot find distilled water.

 

My light came on a few times last fall. C400, slightly over 50,000 miles. After researching the forum, seems like there’s no exact reason why, but the level drops over time. I bought the proper coolant at O’Reilly’s and topped it off. No light since, but this thread is reminding me to go check it.

I think the other coolant tank is a separate system for the turbos? (I could be wrong)

 

Hi, I never had any warning and wondering if I should flush the coolant on a C-class w205 ?
Thank you.

 

Thank you, but can you tell me where are the 2 coolant tanks exactly ?

 

here's the reference link: https://mbworld.org/forums/c-class-w...ml#post7481512

 

Boiling water does not get rid of minerals. In fact since water evaporates during boiling the mineral content is even higher. Ever boil a pot dry and see all the white stuff on the bottom of the pot?