Anit freeze smell

Be sure to watch your temp gauge. I have a 240D that just started the same yesterday. I am monitoring everything. I don't see any fluid leaks at all. Only occasionally get fishy-like smell. Carpet along the firewall isn't wet. I am watching the oil for signs of a head gasket leak since I just changed to a lighter oil - better for cold weather starting. There is no noticable loss in radiator fluid right now. I am thinking (best case) that we have a pin hole size leak somewhere in one of our older hoses. Weather has ranged from 7 to 58 degrees in the last few days. If it is your heater core, I have heard you can pull the dash - take out the core, and it to a radiator shop They can usually reseal the edges. Never did this myself though. Also check underneath your water pump for a leak in the seal or housing. I am going to do a radiator flush first to see if something is plugged - see what happens and replace with Mercedes Radiator fluid....which is about $9 a gallon cheaper than GM's Dextran by the way.

I have the same problem. The only difference is I can see the crack on top of the radiator. You my just need a cap for your overflow reservoir to solve the problem.