Why is your 1973 Mercedes 450sl overheating?

Why is YOUR MB overheating?

There are plenty of reasons why, so you should check to see if there is/are:

1. enough water/coolant in the system.

2. leaks....hoses, radiator, seals at the thermostat and water pump.

3. working thermostat

4. working temp sending unit.

5. fluid on the interior foot areas

6. good heater core

7. head gasket leakage

Now, is this overheating constant?

Is the overheating only when you're at an idle?

You would need to check the fan clutch...these go bad all the time and cause overheating.

You would need to check the electric fan.

Have you checked the radiator for leaks or clogs? If you have the original factory radiator still in the car, chances are it's clogged up