Having 178000 Km in the clock and suspecting that it has never been done, I think it is time to change the cooling fluid of my 190E 2.3 (1992) as well as cleaning the circuit a bit.
Do you have any advices on how to properly do it (fluid changing and flushing) as well as what type of mixture should I buy?

Thanks in advance.

There has been much debate on this forum as to what coolant to use, so I won't start that up. Whatever coolant you wish to use, CHANGE IT!

Simply, drain the block at the right side behind the exhaust manifold and the radiator drain on the right side rear bottom of radiator tank. After draining, fill with water and keep flushing 'til the water comes out clear, then fill with antifreeze. Some cars have a vent on the top of the thermostat housing to allow the coolant to fill without air pockets before starting the engine.

You should flush it annually.

Have a great day,

Thanks!
I knew that I had to change it. Unfortunately, the previous owner didn't ;-)
The temperature of my engine is fine when running (around 80deg), climbs to 100 deg when in a jam and eventually to near 110deg, and the exterior temp is about 10-15deg at this time here.
The clutch of the fan does engage.
From these symptoms I assume that the fan is ok, the thermoswitch is also ok and so does the thermostat and water pump, right?
Should I expect a decrease in temperature (at least when stopped) only by flushing and renewing the coolant fluid?

Thanks!

really good job, after flushing with water (don't forget to turn the heater on high), then drain the tap water and replace with distilled water and af with a 40/60% ratio (af/water). Personally, I use MB af.

You should be able to get two (2) years intervals before service.

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Regards . . . . JimF
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'94 S500 Cpe

Visit my Mercedes Web Page

I agree with JimF.

I believe that most cooling systems are ruined by tap water so I avoid it like the plague.

comments, I recently flushed the cooling system at my tech's shop.

While on a lift, I removed the bottom radiator hose, and you could plainly see the bottom portion of radiator internals; it was as clean as new with no lime, calcium deposits that do accumulate with tap water.

__________________
Regards . . . . JimF
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'94 S500 Cpe

Visit my Mercedes Web Page

when I do a coolant change on my 1998 C230 with automatic climate control - should I simply keep my settings on automatic mode when I turn the car off snd keep it there when I do the coolant change.

Before changing coolant, drive the car with heat and defroster full on. Leave it that way until after you've changed the coolant. Then run the engine that way again to make sure the coolant is circulated and you get any air out of the system.

Check the coolant level the next morning after changing it and top up if needed. Then set the HVAC back on Auto and the temp back to normal.

@ssanmor

I use MB coolant and distilled, about a 40/60 (antifreeze/water) ratio. I've also had positive results
with RedLine's "WatterWetter" product, of course YMMV.

If it's been a while, or you suspect it's never been done, now's probably a good time to replace the thermostat.

@all

Any comments on tap water (or filtered tap water) vs. distilled? I've always used distilled, with the thought
that mineral deposits from tap water are a negative. (Especially after seeing a few very corroded MBs.)

Thanks for all that help.
Do you guys think that, given the symptoms my car shows, the thermostat may be bad (or at least not-so-good)?
I recall that it runs fine at 80deg when at speed, at about 100deg when stopped and sometimes up to almost 110deg. If the thermostat was bad, I suppose that it couldn't be cool even when running, true? It sounds to me more a low water cooling capability or radiator efficiency matter.
Please illustrate me as I am not very familiar with the cooling system.

Best regards

I have changed lots of radiators over the years but never have worked on Mercedes. My 95 E320 has the same symptoms as you described. How to I get the coolant to flow into the system from the fill tank after changing the thermostsat and now flushing and filling. You can't be too basic. Thanks. Dave

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drk

Remove the thermostat housing and the thermostat so that you can fill the engine block with coolant/water mix. Reinstall the thermostat and the thermostat housing then fill the radiator with coolant/water mix and add coolant/water mix to the expansion tank. Run the engine up to operating temperature and add more coolant/water mix to the expansion tank as required.

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Fred Hoelzle

MB specifies 'demineralised' water for the mix. Consensus from the posts I've read seems to favor distilled water over tap water to meet this requirement for coolant mix.

An automotive engineering journal I subscribe to specifically mentioned calcium as a mild poison to cooling systems. Most tap water contains small levels of calcium.

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95 E320 Cabriolet, 169K

It doesn't sound like you have a serious problem with your cooling system. However, if you drain and flush the system you might want to replace the thermostat and maybe the upper radiator hose. The cost in parts will be between $25 and $30. It's an easy job.

Make a note of how the thermostat is oriented when you take the old one out so that you can put the new one in the same way.

Be careful when you remove the hose from the radiator because it's probably got a plastic connection that could break.

Thanks, hope you are right in that there are no serious problems. I was thinking on a clogged radiator or something, I hope it gets ok with a simple fluid flush and change.

About the thermostat, are there different models for a given car (depending on the temperature) or are all the same?


Best regards
Sergio