Hello I am new to this forum and I have heard good things about the experts here. I just bought a 1997 E 320. The radiator was leaking so I replaced it. It is overheating and I need to determine why. I removed the thermostat and found that someone removed the internals and left the outer ring. How can I verify tha the water pump is pumping without removing it?

 

Update I installed a new thermostat and temperature is 90 degrees C.