Mercedes W166 ML350 Bluetec Coolant bleed Flush drain 

yes, I did multiple drains/fill until it was clear

@@kenkanfix was the motor running or did you just fill and drain and run the motor each time? I guess so or the water pump wont work LOL..... I answered my own question.... my problem is the coolant level sensor is bad cause I get a rad fault light... and now it became a check engine light... my reservoir is full... I drove the diesel a couple hundred miles and it ran fine but popped a check engine light.. I got another reservoir ... so I may as well flush it when I change the res and hope for the best.... thanks for the info vid...

Hi, I think it was 12 litres. I used 25 litres distilled water and 15 litres pre-mix coolant for this job.

Hi, the coolant I got was pre-mix so I didn't have to mix with distilled water.

Hi mate What type brand of coolant did u used ?

I ran the car for 5 to 10 mins with the overflow cap off as shown in video

Hi, I had to apply more force to turn just past 90 degrees, then it was easier to get to 180 degrees. I was a bit nervous to be honest 😀. Good luck.

@@kenkanfix thanks. I will try to spray some WD-40 and lithium grease later and maybe try to pull it out while rotating it with a 90° plier.

Yup same problem for me. Got nervous and closed it. Didn't want to mess up the plug or break it in radiator.

Did you try it? Pls share experience going from 90 to 180 degrees on petcock.