MY 1993 400SEL MERCEDES BENZ IS OVER HEATING, I JUST CHANGED THE WATER PUMP AND ITS STILL GETS HOT. WHAT CAN BE WRONG WITH IT.

Or a Air pocket, it happens when you fill coolant to fast, run the car with coolant cap off to see if is going down, your thermostat required to reach a certain temperature to open up..hope this helps before you go spend a bunch a money, it could as simple ad bleeding the coolant system..

head gaskets

fan clutch . or the electric fan . relays or fan switch.

possible causes and solutions to your problem:

1. leaks in the radiator / water hoses. have a radiator expert check your cooling system. water hoses are quite easy to replace. some would recommend replacing your radiator, some will suggest have it overhauled. if the price is almost the same, the go with the new radiator.
2. busted head gasket. this problem is not that serious, but needs immediate attention. due to blown head gasket, some oil and water that is circulating around your cylinder head will mix, thus the dark color of your water
3. cracks in the cylinder head. now this is a serious problem. have your cylinder head checked immediately. solution here varies from resurfacing to re-bore and re-sleeving of combustion chamber.

possibly faulty heating water circulation pump faulty check the pump. is this information helped you. please vote me and leave a comment.

hi
maybe your had a blown head gasket .try pressurized your cooling sytem about 40psi wait 5 mins if pressure drop in mins you have blown head or leaks cooling system or try changed your thermostat

Hi:
I am pretty sure you are asking about a part called the heater core.

It is what gets hot ,and your fan blows across it, providing heating and defrost.

I had the same problem, took to a benz dealer, it was the fuel pump relay, cost for repair $200.

hello,seem your thermostat element maybe defective,if you change with new one,ask a lower degrees for early opening of thermostat element,ty

Check your fuses first.Does the temperature gauge read normal operating temperature (at least 80 degrees Celsius) if not replace your thermostat.  Does the car have any heat while driving at higher RPM's? If so then you have a bad circulation pump. There is also a hot water valve (mono valve) that could be stuck in the closed position and not letting any hot water flow to the heater core.