Hello again

So I've realised that with the W212 coolant leaks are quite common.

I think this developed because one night I had kept the car in sports for about 80 miles and literally kept my foot to the floor and was harsh accelerating all the way.

With this particular issue I can see coolant spaying out from just above the alternator pulley, when the engine is running. Does anybody the exact location of where it may be leaking from or is it possible that it is leaking from a few different areas?

I kept a piece of cardboard under the car and in about two and a half days the left side (driver side) of the cardboard was completely soaked and when I started the car I noticed a few fresh drops. When I checked the coolant tank there was still about 1/4 of coolant left in there.

 

Get a mirror or a boroscope or whatever you need to find the exact source.

Since it's spraying out, you're lucky that the source should be obvious, once you can get a direct view on it.

I can't imagine you're lacking space with a 250 engine...

 

Well well well Mr Chuang Tzu how goes it? Do you reckon that I drive the car hard, all the time, it will be a very common issue? Unless I keep it serviced?

Yeah you're right if it's spaying out then it should hopefully be obvious for him to see.

It's going to the garage on Tuesday so I'm not driving it until then but I want to save his time and try and get the car back before next weekend as I have to travel.

 

I got confused with coolant on the alternator leaking onto the driver side floor cardboard.

I think ALT is passenger side near where coolant tank is mounted.

Coolant tank has a built-in discharge overflow conduit.
If the engine accumulates extreme in dry pistons, coolant gets heat soaked AFTER engine stop.
It builds up extreme pressure to force coolant overflow through the cap.
Realize this static heat level can warp heads and crack head bolts on.

The better way to go may be to spray cool pistons. Rings stay clean to evenly seal compressions. Engine develops normal power instead vibrating loose mounts.

 

Assuming the plumbing in your car is like mine, I think you will have to be on constant lookout for coolant leaks. Every time you do some work around old coolant pipes, replace them. There are some you should replace in groups pre-emptively. I think they made the coolant pipes in these cars with recycled garbage. And there are definitely some weak mechanical points in the design. (See below)

 

U never tell us what engine you have. E250 can be gasoline and also diesel.
Is this using M271.8xx EVO engine ? The gasoline turbocharged one ?
If M271.8xx EVO engine, coolant leak is its gift ,,,, if at this age.
I can show you the guaranteed leak points.