Coolant Flush

[EasyManHugo]

W210 E300TD (98) OM606

I've bought Merc Dealer Antifreeze....I want to replace the existing with the good stuff. How do I thouroughly flush the system to ensure that there is no mixing.

Also I'm not sure what antifreeze is in there at the moment (if any). What are the chances of long term damage if the previous owner only used water??

Many Thanks

EMH

 

[johnsco]

I wouldn't worry too much.
As long as you use a good quality glycol-based anti-freeze with corrosion inhibitors (and I think they all have this) ... Then you should be fine.
Use a 50% mix ... That is important.

I ran one of our E300TDs using the "blue" stuff.
My present one is filled with the "orange" stuff ... I 'm not sure it will make any real difference.

Our E430 (year 2002) is filled with the blue stuff.

 

[markjay]

What I used to do was to flush a couple of times with plain (soft) water, allowing the engine to reach working temperature and heat circulation through the cabin, before finally draining and filling up with proper coolant.

Also, if you measure the amount of water you need to add each time and compare this to the car's overall coolant capacity you will get a good idea of how much is left in the system after draining, and you can then reduce that amount from the quantity of water you add to the coolant.

 

[markjay]

The blue stuff is regular coolant that needs replacing every 1 or 2 years, the orange stuff is long life coolant that need replacing every 4 to 15 years (depending on application).

 

[millo777]

It depends how much time you've got, and how much crud is in the system. You can usually tell from the state of the expansion tank. If time isn't an issue and you're doing the work yourself it wouldn't hurt imho to flush as much as possible using a free running hose. I did my w124 in the summer and used 2 bottles of wynn's coolant flush with tap water, left on idle for an hour with the thermostat removed, then did the same with 1kg of citric acid dissolved in boiling water. They both turned interesting shades on draining so assume they did some good.

I've read that the two main types of coolant IAT (blue) and OAT (red) don't play well together when mixed, so if changing from blue to red or vice versa it might be as well to flush the system before adding the new antifreeze.

 

[silver_star]

You need to also remember to remove the drain on the block.

I flush the circuit both ways including rad etc.

MB do actually sell a special cooling system flush.