C36 Coolant Leak
 

A few weeks ago, I drove my car with the AC running and the temp outside was close to 90F. During the 30 minute drive, I noticed the temperature rise above what is normal for my car. An led on my dash flashed for about a second and disappeared. When I got to my destination I checked for leaks under the car and could not find anything, but I smelled coolant in the engine bay. After about an hour, I checked my car again and found coolant underneath the car directly below where the water pump is. I added a little more coolant and then drove home with the AC off. My mechanic has not had a chance to look at my car, but since I drive it only on weekends, I've driven it several times after the coolant leak and no other problems have occurred.
Is this a sign that my water pump is ready to go out? Is it normal for leaks like this to happen and then suddenly disappear?
Any advice would be appreciated.

Did you check if the water under the car was coolant and not water from the AC-condensor? On a hot day I can also feel the smell of coolant without having any leaks.
If it happens again, make sure it is coolant and not condensed water under your car.
Regards/L.

The small puddle under the car had some coolant mixed in with it because it was slightly green. Do water pumps slowly break down like this, or does it just completely go out? There seems to be some dry coolant traces on the top part of the water pump but no noticeable puddles anywhere else.

"slightly green"?....... Are you using the MB coolant or the green stuff?

What can happen is the thermostat is stuck by some debris for a little while and the pressure on the system rises so a slight leak can develop anywhere and then disappear when the thermostat opens again.
But, the flashing led is strange, can´t think of any such connection? Maybe it is visible in the cars memory?

Anyway if the pump is starting to leak it will continue and soon enough you will also be able to hear some noise from it.

If no more coolant disappears and no more puddles under the car, it could have been the thermostat. Check that all hoses are tightened as well.
L.