nsupra

Hi,


I recently had my anti freeze replaced with OEM coolant from mercedes. Since replacement i have put on about 200 miles or so and have gotten 3 messages randomly saying "COOLANT LEVEL" i supplied the guy with 2 jugs of the coolant. How he mixed it or if he mixed it with water i do not know. The 2 jugs were emptied for sure i saw.

On top of that message that i get every so often i also noticed that my car doesn't produce the burning heat like it used to. It blows out warm air, but not like before where i had to lower it to speed 1 because of how warm it would get in the car. I read around that it could be the thermostat being stuck open, but why would it screw up right after? Would adding water produce more heat or adding more coolant produce more heat if its low?


Now my question is. Since i do not know how the coolant was mixed should i pick up one of the prestone coolant testers and try to figure out the mixture it is. Is it safe to just add water, or distilled water. Or vice versa throw it coolant with ought mixing it.

Also while im at it the whenever i choose if i want the heat to blow at me or below or above it never really works. Is that a problem with the Duo valve. Cleaning it would work maybe?


Thanks a lot any help is greatly appreciated.

RichardM98

BTW, including your location is helpful when replying to questions like this one. "One man's winter is another man's spring" as they say

For starters you want as close to a 50:50 mixture as possible for both corrosion protection and heat transfer. So getting one of those testers is a good idea. I've compared those to a lab hydrometer and they are pretty close.

I think some of the testers only give a temp value so here is a conversion chart:

Protected to...............%MB Antifreeze
-22F..................................45%
-35F..................................50%
-49F..................................55%

Anything in the 45% - 55% range is considered acceptable by MB

Have you physically checked the coolant level? When the engine is cold, take off the expansion tank cap and look inside. You should see a little square tab just off center at the 9 o'clock position. It should just be breaking the surface. That is the telltale for checking the level.

If the ratio is good and you need to add a little, either distilled water or local tap water is fine unless you know your local tap water is exceptionally hard or acidic.

As far as heating you may have a thermostat issue or a duo-valve issue. Sometimes a sticky duo-valve can be freed by just lightly tapping it with the end of a screwdriver handle. BTW, is there a blizzard outside? MB takes it's air directly from outside (vents on hood) and the colder it is the more work it takes to get the air really hot. Also much harder to heat when moving as opposed to idling. I used to live in the upper midwest and drove an MG. In the winter I would let it warm up for about 15 min with the heater on so the interior was warm. Five miles up the freeway it was about as cold inside as out.

Good luck.

saintz

Sounds like you need to add coolant. Check if the reservoir is empty. You should be able to add distilled water. If it takes more than a half gallon, you might want to start adding coolant. The mixture doesn't need to be exactly 50/50, particularly if it doesn't get too cold where you live.

nsupra

I am located in CT currently. I should update that. its been around 15-20 degrees outside.


thanks a lot guys. you have been a huge help! Ill report back if i run into anything else.



I will check everything out tomorrow.

Thank you very much.

nsupra

by the way is it ok to use zerex g05 coolant if i need to since i used OEM mercedes coolant first? Will they blend with ought any problems.

ohlord

Temp just protection limits. Fill volume will affect temp from climate control so check above advice to check level in res.
And yes you can mix 50/50 GO5 brand with MB fluid it is the same formula just a different color dye package.

nsupra

Hi, so my tank was actually low. Low to the point that i could not get a reading from the tester cause it did not reach. So i filled it up with water up to the point where the line is in the reservoir which i believe is the indicator about a quarter of water. about 20 miles later i decide to test the coolant using the tester.

The results were in the -50F and up. Off the chart.

So should adding more water help? Is there a way to add more water to the actual radiator vs the expansion tank. Also i noticed on the cap there is a hose attached to the tank exactly on the neck of the cap hole. It is a small hose that goes no where. Is that supposed to be attached to anything seemed like it was a over fill hose.

thanks

RichardM98

The expansion tank is the correct place to add to the system.

Sounds like the mechanic added the MB antifreeze without diluting it. Maybe he thought it was a 50:50 blend. If you're a DIYer you can drain the radiator, mix in water until you get about 50:50 and then put as much back in as necessary to achieve the correct level. That should get you in the range of 45 to 55%.

On second thought, I would take it to the people who serviced it and have them adjust it to 50:50.

nsupra

thanks!!

nsupra

the bit of water that i added made a difference i noticed for sure.

ohlord

Hose.
Yippie

RichardM98

Then maybe it's not that far off. If it was -50F plus before you added the water and now its above -49F you are in the high part of the range. If that's the case, I would just check the level periodically and add water as needed. However, if you are continually adding water then you need to find the leak.

Good luck.

nsupra

Just an update.....


So i removed exactly 1 gallon of pure coolant since i had 2 gallons of pure coolant in there already.

I replaced it with 1 gallon of water.

Should be a 50 :50 mixture.

Problem is that the tester does not tell me its mixed 50 50. It shoots up to the point where it reads out pure antifreeze.

Now what could be the problem?

Also i noticed that the car runs hotter than i think it should for our current weather.

For example in 70-80 degree weather i see the temp guage goes up to 95-close to 100 Celsius.

I would assume it would reach that temp when its like 90 plus outside. Otherwise stay consistent at the 80-85 mark.

Do you think i need to replace my thermostat? Maybe its not working right so it doesnt cool properly.
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RichardM98

Could your tester be defective? If you have any MB conc left, make up a 50:50 mixture in a measuring cup and test it. Should be 50:50 or -39F on the nose.

It could get a little warm when in stop/go traffic, climbing a grade, etc. but it should go back down as soon as that condition changes.

Do you have an auxillary fan on the radiator? Mine has dual fans but I know they made some changes after MY98. If you do it may not be working. If I've been on a long drive on a warm day, the fans will come on if I leave the engine idling. It usually takes a few minutes for it to happen.

Also, yes, your thermostat may be failing since when it doesn't open fully coolant flow is restricted and the engine runs hotter. You can test the thermostat but by the time you remove it and test it you might as well have bought a new one. MB thermostats are premounted in a housing and you must buy the whole thing so a little expensive. Thermostats do fail with time so a replacement on an older car is not too unusual. About $30 at autohaus

Another cause of overheating is a plugged radiator but if you've been servicing it regularly that's not very likely. You can test for that by using a handheld IR thermometer to look for cold spots.

Good luck.

nsupra

Thanks for the reply yes the thermostat does go back down when on the highway or maintaining a speed.

i also have dual fans, if you hold down the auto buttons on the climate control for 10 secs or so they turn on as a test.
Otherwise in normal operation I hear them come on every so often cause they are very quite. So i think they work.


I may try another tester and change my thermostat. Wouldn't be surprised if its failing after 120k

ill report back if anything else comes to mind.

thxx