W204 Coolant question?

[DeviAngel]

Hello everybody, I'm new to the forum and English is not my native language, so If I make mistake I'm sorry.

My story...

I bought a W204 2009 C200. I never had any problem with temperature of the car (Max that it got in traffic and hot hot days was 85/87).

When I did my service (oil change ) I decided to change the coolant (while once while driving in traffic on a very very hot day it reached 92 and the FAN DIDN'T TURN ON)...

When I went to the MB service they noticed a little oil like fluid in the coolant... He started the car, no white smoke was coming, the oil is CLEAN.

After we did the oil change (the old oil had no traces of coolant) he flushed the engine (engine off) and the reservoir and expcet for small slimy things nothing came out.

The mechanic also noticed that before the owner used BLUE coolant and now inside is RED.

After everything was done I drove home (around 10km) and I noticed small thins floating again in the coolant reservoir (he did say he didn't clean everything).

I called my friend who is also mechanic and he said to collect the small slimy things and floating thing with a edge of a towel. I did that 2-3 times when driving and until now I have no problem only from time to time the slimy things appear but no foam or anything..

My question is, what can cause this? Knowing that my oil is clean, dipstick oil is clean, on the cap there's nothing and the temp goes to max 87 when hot hot (the fan doesn't kick in, I dunno why but when I turn AC on it spinns) and only in traffic, when I drive it on open road or not sitting in place it goes back to 70-75 in instant)

What I collected after the flush was done.

(since I drove like 1k kilometers and therer's no more of this).

Now my reservoar looks like this


..

I can see the walls of the reservoar and the black plastic...It's a little dark but no sign of foam, no slimy coolant on the cap like Nescaffe or something like that...The dipstick is clean, oil cap is clean, temp goes to max 87 when staying in a busy traffic, when driving goes back to 70-75 .

Anyone with similar experience? The guy at MB said maybe its from the old coolant ( was not changed more than 3 years) or it was used wrong coolant.

Thank you for your time

 

[AMGeed]

Welcome to the forum.

I have a 2009 C180 and the correct MB coolant is blue.
Coolant changes are every 15 years I believe.
I don't think you have a problem going on your description but I wonder if you need a new thermostat?
Although you reach the operating temperature of 87c, it should stay constant whilst driving and not drop to 70/75c

Its a simple DIY job if you decide to change it., air intake pipe off, two torx bolts to remove the thermostat housing,(be careful not to break the plastic housing), push a rag in the block to prevent wasting coolant, new Wahl thermostat and gasket and gasket and refit. The job takes 20 mins or less.

 

[DeviAngel]

Welcome to the forum.

I have a 2009 C180 and the correct MB coolant is blue.
Coolant changes are every 15 years I believe.
I don't think you have a problem going on your description but I wonder if you need a new thermostat?
Although you reach the operating temperature of 87c, it should stay constant whilst driving and not drop to 70/75c

Its a simple DIY job if you decide to change it., air intake pipe off, two torx bolts to remove the thermostat housing,(be careful not to break the plastic housing), push a rag in the block to prevent wasting coolant, new Wahl thermostat and gasket and gasket and refit. The job takes 20 mins or less.

First of all thank you for your answer.

Those slimy things make me nervous every time I see them but what is important is that the oil cap and dipstick are clean. But the coolant on the picture and in person Is like on the picture (shouldn't it be a little lighter?)

Wow once 15 years? In my country people change it after 3 years...

Do you have a picture for the termostat? I tried to find it but so far unsucessfull.

It drops to 70-75 when driving longer or on open road. In the city it usually stays 78-80. Just as I said in hot time and reall trafic goes to 87-90 maybe.

 

[Wighty]

I don’t think you can still buy the MB Blue 15 year coolant .

 

[EmilysDad]

I wouldn't trust coolant/antifreeze in for 15 years .... I'd be thinking 5 or 6 at best

 

[EmilysDad]

Hello everybody, I'm new to the forum and English is not my native language, so If I make mistake I'm sorry.
.....

It's very hard to tell!

Most of us here can only speak English!

 

[Wighty]

I wouldn't trust coolant/antifreeze in for 15 years .... I'd be thinking 5 or 6 at best

That’s why you don’t have a job in the MB coolant development factory buddy
Next you will be saying that engine oil doesn’t need changing monthly !

 

[EmilysDad]

.....
Next you will be saying that engine oil doesn’t need changing monthly !

Monthly?!? I thought oil was done every other Monday!

 

[rf065]

I wouldn't trust coolant/antifreeze in for 15 years .... I'd be thinking 5 or 6 at best

I sold my CLK at 13 years old with 150,000 miles on it, never had the coolant changed from new and never had any problems with it.

 

[ajlsl600]

Don't f with wots OK.. If worried do a 2x coolant flush and start again.
Check if trans cooler runs thru scoolant rad. Keep eye on that.

 

[AMGeed]

Do you have a picture for the termostat? I tried to find it but so far unsucessfull.

Thermostat pics as requested.
1st photo is old thermostat with plastic housing.
2nd photo, new thermostat fitted into housing ready to bolt onto block.
3rd photo, Wahl brand thermostat as used by MB.

Genuine thermostat for sale link below. Read full ad for seal that you need from main dealer along with Part number.

Mercedes-Benz Om271 Petrol Engine Cooling Thermostat A2712030575 Genuine for sale online | eBay

Find many great new & used options and get the best deals for Mercedes-Benz Om271 Petrol Engine Cooling Thermostat A2712030575 Genuine at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

 

[DeviAngel]

Thank you very much for all of your replies and everything.

 

[LostKiwi]

You need to be careful when replacing coolant to flush all the old coolant out and to use the correct spec (usually G48 which is a greeny/blue).
If you mix two incompatible coolants they can cause gelling to occur. I suspect that's what happened in your case. The residual coolant reacted with the new coolant forming slimy gel strands.

If in doubt check the bevo pages on the MB website in conjunction with the owners manual.

Mercedes-Benz Operating Fluids

Publication platform for approved operating fluids from Mercedes-Benz

operatingfluids.mercedes-benz.com

 

[mioba]

I sold my CLK at 13 years old with 150,000 miles on it, never had the coolant changed from new and never had any problems with it.

MB coolant is 15 years interval

 

[mioba]

To the OP if it aint broke dont fix it.

MB coolant systems are very good, i have never had temp fluctuations when driving a MB as you describe.

check the antifreeze conc. may be too strong.

 

[rf065]

MB coolant is 15 years interval

I know that, I was answering post number 5.

 

[AMGeed]

Thank you very much for all of your replies and everything.

I forgot the thermostat photos
One of the old one, one of the new.
Note the new sealing ring on the housing.
That is what you need to buy in addition to the thermostat in Post #11

 

[AndySlade]

Unless genuine MB coolant, the colour means nothing. I would check what MB spec is specified for the specific car in question. There have been multiple specifications for anti-freeze over the last few years, flush system out and refill with correct spec.