Very odd heating problem
 

On my 1987 190e 2.3-16V, i had an odd experience today. After warming up the engine before coming into work, i started driving. Then about 100meters down the road, i turned on the heater and STEAM came from the passenger and driver's side vents! I have never had this happen before. Also, it only blows super hot air. First thing that comes to mind, is the heater cracked? Any ideas??

Strange indeed. Hopefully someone will have more insight on this mishap.

Did the car overheat, or did it remain at normal operating temperatures?

Leaky heater core, if it was my car I would first put in alumseal and try to seal the heater core with that, turn the heater up to high, fan on low and add this to the radiator being careful not to open under pressure or when hot as not to burn yourself, if that does not stop the leak then you have to change the heater core

okay thanks a lot. Ill try that out. It only happened this one time. Car operates at normal temperatures, thats why I find it odd.