DIY: M271 coolant drain/fill





Coolant systems on euro cars are different from Japanese cars (your picture).
I like to know the systems capacity so have an idea how much air is in the system when showing full in the overflow tank .
I have found that by putting ones mouth over the filler & putting a light pressure on the system helps push the coolant through . Also squeezing the radiator hoses when the engine is running & cap is on, aids the process.
My previous car had a vent valve at the top of the system which was very useful in removing the air.
I like to bring the car up to operating temp with the bonnet up monitoring the situation & taking the steps as written above to rid the system of air. Then shut the engine off & let it cool to ambient before refilling the overflow tank.
The Best of Mercedes & AMG

All engine blocks have a drain plug.
I like to know the systems capacity so have an idea how much air is in the system when showing full in the overflow tank .
I have found that by putting ones mouth over the filler & putting a light pressure on the system helps push the coolant through . Also squeezing the radiator hoses when the engine is running & cap is on, aids the process.
My previous car had a vent valve at the top of the system which was very useful in removing the air.
I like to bring the car up to operating temp with the bonnet up monitoring the situation & taking the steps as written above to rid the system of air. Then shut the engine off & let it cool to ambient before refilling the overflow tank.
idk if i would put my mouth over it? but ty for the advice on squeezing the hoses
btw. i know if u mix some coolants together. it might turn into a gelly pasture. peak okay to mix with mb antifreeze?





Going to pick up some Zerex G05 coolant this evening.
How many gallons of coolant do I need for a full drain and flush on my M111 engine?
Also, I believe its a 50/50 ratio of coolant to distilled water...can someone confirm?
Thanks.

Make sure what you buy is concentrate & not premixed. Practices vary around the world.




Can always return the unused bit.

I also understand there are some coolants that are not poisonous and won't make your pets sick, but I don't know if they are approved by MB.
Last edited by ncmudbug; Dec 19, 2011 at 11:20 PM. Reason: clarifying a point.
I believe your 2002 C230 with M111 only holds 8.5 litres of coolants in 50/50 mix. 3 Gallon is likely 2 too many,... unless you can squeeze out every drop of coolant including those in the engine block.
BTW, since you're in Toronto, the Zerex G05 coolant (concentrate) is available at Walmart for $18CAN. I found it at the Eglinton-Warden Walmart SuperCentre.




Wow...so just 1 gallon required! Thats awesome. The flush should be a breeze!
Thanks for the info.,
M271 cars uses 8 liters of coolant / distilled water mix
1 gallon = 3.78 liters
thus 1 gallon Zerex G-05 in 50/50 with distilled water = 7.56 liters
Technically your M111 would require 1 gallon plus a bit,.... if you were able to squeeze every single drop of coolant out of your system including those in the engine block (you'll need to purge it from the nut/valve near the header at the side of the engine). Most just drain from under radiator only,... but for completeness you should drain engine block too,...
Depending on how much you can drain,.... you might want to get 2 gallon,... you can always use the extra to top off once in a while,.... especially if coolant level sometimes drop in your reserve. This stuff is hard to find in Canada, so grabbing a little more doesn't hurt.
They have 50/50 premix at almost the same price,... go for the concentrate Zerex G-05 with black cap. UPC code: 02-8882-50149-1
Interestingly,.... for my 2003 C230 coupe M271 booklet says coolant should be good for 15 years or 250,000km. Label on Zerex G-05 says good for 5 years or 240,000km. Just interesting since Zerex is OEM Mercedes coolant maker,... I guess that means flush at 5 years to be safe.
I did get a gallon of the Mercedes Q3 03 0002 antifreeze which is orange-ish in color. I'm kind of **** with this stuff, so I flushed the system (i.e. filled w/distilled water, ran car up to operating temp, then drained) 3 times. I know - probably excessive, but I wasn't sure if I really wanted to mix.
So am I interpreting earlier comments in this thread correctly, and the orange stuff only good for ~2 years?

The orange stuff will last as long as your original. Just not 15 years because you don't have the silica gel sachet in your surge tank.
Last edited by Glyn M Ruck; Dec 31, 2011 at 06:13 PM.



