Over new years I spent time at
@Adunaphel's and others. The second day a
@loose_unit sends me a photo of a greenish wet spot under my car.
It would seem a leak in the radiator has started and 2 hours later grew. I assessed, checked the overflow tank and it had, what I would consider as still ok, Mercedes says Nein.
So I put some coolant in, let it warm up, drove around the block to get up to operating temp, parked it for 6 hours. Took some finalgearians for sushi with the rest and checked the following morning. The leak was less this time around but still there, not enough to make the system go "ACK ACK" but it went down. I decided to drive over to
@loose_unit's and assess better.
What you could see if you closed one eye, and looked from the fan blades in the lower drivers side is a wet spot with coolant seeping out. It's not immediately noticeable because the W211 Mercedes is aerodynamically covered up and so you have to fill up the cover before it overflows from the drain holes.

AS A HOLDOVER TO GET HOME, we got some radiator stop leak, ran the engine for 10 minutes with the heat on high and shut it off. I checked this morning, and there was no extra coolant outside of the little bit that came out the first time when stopping here was found. So the stop leak is actually holding. This will keep things from hopefully getting worse and give me time to find a shop.
Mostly though, I am ok with the stop leak for this reason alone:
View: https://www.youtube.com/watch?v=q3_kDiQb7lE
I will not be leaving it for a year or more, but it's not like this stuff is going to completely gum up passageways like the Rule of Thumb mechanics like to tell you. I have a 3.5-4hr drive home, so yeah, I would prefer to not have a coolant leak.