Coolant level low 'error'
Thread Starter
Member
Joined: Apr 2012
Posts: 80
Likes: 7
2012 ML350
Coolant level low 'error'
I have a 2015 ML400 with 20,000 miles and today it reported "coolant level low". I checked under the hood and the coolant level is fine ... After the car is running and gets up to temperature, the error message goes away. After the car cools down (overnight), the error comes back.
Could this be a sensor problem?
Could this be a sensor problem?
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
Did you check the windshield washer fluid level?
I understand the error is pointing at the coolant level. Check the windshield washer fluid level... It's easy to check...
I understand the error is pointing at the coolant level. Check the windshield washer fluid level... It's easy to check...
Thread Starter
Member
Joined: Apr 2012
Posts: 80
Likes: 7
2012 ML350
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
I don't know if that is the case with W166. That is why I said, check it. It doesn't cost you anything and you can check it in couple of minutes.
I typically try to check and eliminate the obvious and easy stuff first...
It's just a suggestion, you can decide what you want to do with that suggestion
Thread Starter
Member
Joined: Apr 2012
Posts: 80
Likes: 7
2012 ML350
On w203 (c280), coolant level sensor and windshield fluid level sensor are connected in series. So, low of either of those fluids, light is triggered.
I don't know if that is the case with W166. That is why I said, check it. It doesn't cost you anything and you can check it in couple of minutes.
I typically try to check and eliminate the obvious and easy stuff first...
It's just a suggestion, you can decide what you want to do with that suggestion
I don't know if that is the case with W166. That is why I said, check it. It doesn't cost you anything and you can check it in couple of minutes.
I typically try to check and eliminate the obvious and easy stuff first...
It's just a suggestion, you can decide what you want to do with that suggestion
Thanks
Member
Joined: Jan 2014
Posts: 236
Likes: 30
From: Florida
2013 ML350 Bluetec, 2016 C3, 2020 Lincoln Aviator
I've had this message before. Coolant level seemed OK but I added about a quarter cup of distilled water to the coolant reservoir and the warning went away. Seems the sensor is easily triggered.
Trending Topics
Thread Starter
Member
Joined: Apr 2012
Posts: 80
Likes: 7
2012 ML350
I suppose that the water evaporates over a couple of years ... just enough to trigger. I thought it was a closed system - but probably not 100%. I'll have to check again more closely and add some distilled water. It's pretty full right now.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Member
Joined: Apr 2012
Posts: 80
Likes: 7
2012 ML350
I heard back from the dealer (took the car in for routine oil change). The service tech told me the sensors for engine coolant and the windshield washer are completely separate. One does not affect the other. He said the coolant in the reservoir was a tiny bit low and they topped it off. No pressure leaks or any other issue.
The ML400 is two years old with 20,000 miles. I presume that in that time some evaporation of the coolant occurs even though it's a closed system. I don't think I'll see this warning again for another 20,000 miles.
The ML400 is two years old with 20,000 miles. I presume that in that time some evaporation of the coolant occurs even though it's a closed system. I don't think I'll see this warning again for another 20,000 miles.
Senior Member
Joined: Sep 2012
Posts: 323
Likes: 31
From: Ottawa ON Canada
2015 ML350 Bluetec
Sorry, a little late to respond... Yes, coolant level is a bit low, even though looking through the reservoir looks good. Top up with coolant(1/4 cup) and all will be fine. Had this 2x now... negligible amount!! Sensitive sensor in reservoir.
