Coolant Leak From?
 

A while ago I read a very good posting about the same thing, but cannot find it, and I am a little pressured for time.
I CANNOT located the darn source, I am assuming is the water pump. Have been using my trusty dentist's mirror to no avail.
See pictures.
http://C:\Documents and Settings\Sua...s\P1010017.JPG

Oh well, I give up on trying to post pictures
 

For some reason cannot upload them

99% sure it's the water pump. It leaks from the shaft seal behind the pulley, leaks down to the lowest part of the water pump, along the ridge along the oil pan flange and down to ground near the left motor mount.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Yes it weep for awhile and then fail. I just had mine replaced on my 84 300D after weeping for 4 months. I was eventually adding a gallon of water a week. I wanted to get it fixed before the winter.

Yep, leak dripping by the oil drain plug, can see it coming down by the oil sensor too. I am trying really hard to locate it behind the pump.
It is funny, I drive the car for a while, and the leak stops.
Let it sit overnight, and starts leaking. Heat expansion playing tricks with my head.

I had the same problem a few weeks ago. I thought at first it was the water pump, but i saw no dried residue from the pump weep hole. Then I followed the dried streak up to the thermostat housing area. And i found a few droplets on the lowest part of the housing. I tried to reseal but it continued to leak. I then replaced it with a spare i luckily had from my old engine. Then it stopped. I had the same symptoms, in that i could drive the car and there was no leaks. Then let it sit for a while. I would go out at lunch time from work and take a look, and i could see the leak beginning. Then it would stop after it leaked a certain amt. I suspect it had something to do with when the thermostat would release while the engine was cooling and it must have created some pressure and released it out the weakest point in the system.