How do you drain coolant? S204 (w204) t model estate c220 2008 om646 engine

[Bruiserray]

Hi, I hope someone can help.
ive found a radiator drain valve in a recess on the rhs (as you look at it, technically the left as a driver) of the rad. It was in the 12 o’clock position and I can turn it anticlockwise to the 9 o’clock position, it’s a bit stiff but moves okay.
but nothing comes out?
A pelican parts (USA?) guide suggests for some models you have to also pull it out, but it doesn’t budge. Neither at 9 o’clock nor the 12 o’clock position.
I’ve never known anything so simple be so difficult !
please help!

 

[AMGeed]

If there is any chance of breaking something (brittle plastic parts), I'd just remove the bottom hose and let the coolant drain out, then reconnect it.

 

[Bruiserray]

If only life was that simple! I can’t see a coolant bottom hose. I undid what I thought was one, turns out it was some air pipe (turbo, intercooler….??). Hence I am asking the question….about the drain plug clearly designed for the purpose….

 

[AMGeed]

Looking at a diagram of your radiator I see there is no bottom hose. Sorry about that. ( Section 015 and 165 below)

FG 204.008 - RADIATOR,MOUNTING,AND COVERING > Mercedes EPC Online > nemigaparts.com

Parts catalogs. Spare parts catalog Mercedes EPC Online. Mercedes. Car. RADIATOR,MOUNTING,AND COVERING.

nemigaparts.com

Have you tried turning the plastic key past the 9 o'clock position anti-clockwise ? I wondering if it unscrews so far to release the coolant.

 

[Wighty]

If only life was that simple! I can’t see a coolant bottom hose. I undid what I thought was one, turns out it was some air pipe (turbo, intercooler….??). Hence I am asking the question….about the drain plug clearly designed for the purpose….

Have you searched on YouTube ?

 

[mioba]

Have you covered your face in coolant yet

 

[Bruiserray]

So the answer is (I worked it out). As you turn it from the 12 o’clock position, anticlockwise, start pulling and twist at the same time,
like wriggling it out, like it is a cork in a bottle with no corkscrew, pull hard and turn it back and forward, then it seems to be able to turn further than the 9 o’clock position towards the 6 o’clock position and the coolant starts to flow! It’s just really hard to do, i disconnected the large air pipe by it to give me more access.

 

[Wighty]

So the answer is (I worked it out). As you turn it from the 12 o’clock position, anticlockwise, start pulling and twist at the same time,
like wriggling it out, like it is a cork in a bottle with no corkscrew, pull hard and turn it back and forward, then it seems to be able to turn further than the 9 o’clock position towards the 6 o’clock position and the coolant starts to flow! It’s just really hard to do, i disconnected the large air pipe by it to give me more access.

Good job buddy !