PaoPao

Hi, I haven't start up my car for few days, when I started it up this morning, I got a message says check coolant level, car is 2014 model only 21000km, I'm wondering if it might be just normal coolant usage or head bolt related issue. Thanks.

Valvestud

As has been stated many, many times, only all 2010s and older, and some 2011s are affected.


Regards,


Joe

PaoPao

Thans a lot

ToXicXxX

You haven't noticed any leaks on the ground when parked have you? It's also possible mercedes didn't fill the tank up all the way when they last flushed it. Also check and see if your exhaust smells sweet and is fairly white.

In no way would using that much coolant in 21K be "normal" though. My car is at 36K and my tank is still full.

gravfed

I had the same message on my 2012. Took it in to have the dealer check it/top it off and was informed that the coolant wasn't actually low. I was parked on a small angle and must've tripped the sensor. Haven't had any issues since.

Ingenieur

was it cold recently?
the level drops with temperature

the tank should NOT be filled to the top
only ~ 1/2 way, you'll see a black/white tab in it
should touch the black when cold and rise 1/2" when hot
the correct level is very close to the sensor, so a grade or temp drop can falsely trigger it

the manual says check level and add if required, a little loss is normal
a lot in a short period is not

Kriston

I had this warning come up right after my headers were installed.


Temp dropped a bit, I topped it off and no issues since. It happens!

Merc63

I had this message pop up the other day and I have arp studs. I had to add maybe 100-200ml.

bhamg

I've added about 24oz of fluid to the coolant reservoir in the past four years (warm to hot weather driving year-round). I consider this rate of replenishment normal and entirely consistent with every car I've owned.

Ingenieur

The system holds 400 oz
Gaskets leak
Evaporation
Etc

24 oz over 4 years is 1.5% per year
Nothing

How many miles on your car bhamg?

Over filling is bad
It runs hot
And if filled to the brim ( like the %#{#+*+ ) dealer did during and oil change when it expands it is forced thru gaskets, the relief, etc
It is incompressible
If you leave air in the expansion tank the rising fluid will compress the air above it
The system will function properly

bhamg

^ Approaching 44k miles. And Ing perhaps you can weigh in on this. Earlier this year I used the turkey baster to withdraw 42oz of coolant from the reservoir. Not really thinking of the "lifetime coolant" concept as ideal and considering that my coolant top-ups have consisted of 100% distilled water, I added 42oz of pure coolant to the reservoir. My plan is to drain the reservoir every six months and add (this time 100% coolant to get back to 50/50 but a one-time thing) a 50/50 mix of M-B coolant and distilled water, so in two years I will have used up one gallon of pure M-B coolant plus an additional 3/4 gal of distilled water in the process. So, over time, I'm aiming to continually renew the coolant the easy way. It appears that when I check the reservoir when hot I probably see an 8oz expansion, so that 8oz ends up getting sucked back in the system each cooling cycle. Make sense to you?

ToXicXxX

Running pure coolant is not a good choice.

It should be 50/50 or 60/40 if you live somewhere very cold.

Other then that it doesn't do its job optimally and can gum things up.

Ingenieur

Most cars avg 40 mph on their obc
So you have 1100 hours of run time
1 oz / 44 hrs nadda

I don't think you see much flow or exchange in the exp tank
If any very slow
The top hoses are for venting and the bottom is the expansion hose

I would bite the bullet and drain, flush and fill every 10 years (MB specs 15 years 150k miles)
Let's assume 400 oz and you replace 40 oz per cycle, makes the math easier
So you replace 10% new and have 90% old per exchange cycle
2nd time 81% old
3rd 73%
4th 66%
Or (1- 0.1)^cycles
90% new 10% old would take 22 times!!
880 oz of 50/50 mix
Over twice as much as required

bhamg

i think you misunderstand. I started at the OE 50/50 mix. Over time I've added 24oz of distilled water to replenish losses in the overflow reservoir. Now I'm allowing pure coolant in the reservoir to being me back close to the original 50/50. After that I'll be using 50/50 in the reservoir.

Ingenieur

The turkey baster works good on power steering
You get about 40% each time
Refill
Cycle lock to lock slowly a few times, I like to jack the wheels off the ground
Repeat 5 cycles
(1-0.4)^5 = < 10% old left
Takes about 2 liters
System holds ~ 0.8 liter
Do it until you use 2 liters
Perhaps 6 cycles
Close to 5% old left

bhamg

If I'll be at 33% new coolant in the system after two years it's well worth the $25 for the gallon of OE coolant IMO.

Ingenieur

Can't hurt

It's good to drain and flush with a cleaner/descaling agent
Flush again with water
Then fill 55/45 distilled/coolant (depends on where you live) good to -25 F or better
50/50 is -30 F

They say no addatives but I use a bottle of water wetter

ShaneN.

Just came across this old thread when searching some things but do coolant temp runs cooler with headers, or do we think he meant temp was actually hotter under the hood because of headers? Either way could there be any correlation between the headers and coolant? I just got headers done 2 weeks ago or so and my warning just came on the other night. It didn't come back on since that one startup. Thought I'd check it today after buying some coolant and I was about 1.5 cups to get to the full indicator. I can't be certain when it was last actually full either as I've never checked it myself. Happened to check my oil level two days ago at a gas stop and it looked normal, rather clean actually. We also just went from a couple months of hot summer weather to cooler rainy fall weather here in Vancouver. Car is a 2012, I guess if there is an issue it's more likely a leak than anything. Maybe I should have the system pressure/leak tested.

Mort

Since you have topped up the coolant level I would just keep an eye on it. That amount of coolant loss/consumption seems normal to me and happens over a long period of time. It is normal to get the low coolant warning as ambient temperatures drop, as the coolant contracts more in lower temperatures, as the car sits overnight and triggers the sensor warning.