Pressure test cooling system to find leak Could be freeze plug, water pump, thermostat housing, bypass hoses etc.
Coolant goes in the radiator or you can also fill the radiator resevoir.
The coolant resevoir on a mercedes is the same as it is on any vehicle it just might be a different shape. Your coolant resevoir is where you store excess coolant and where exess coolant from your radiator goes.
Low coolant, check radiator and resevoir, if its nit low there is a low coolant sensor that may be bad , this is a knon issue on these cars, sensor is located about 2-3 inches down under the radiator cap on passengersid
You need to check coolant temperature sensor and the water pump.
THE ENTIRE COOLANT RESEVOIR MUST BE REPLACED IN FORDS.ABOUT 35.00 AT THE JUNK YARD FOR WHAT I WAS TOLD WAS A BRAND NEW ONE. SIXTY FIVE DOLLARS AT THE DEALER.
your radiator needs to be replaced
On top of the radiator. If there isn't an 'obvious' cap, then there really isn't a conventional type cap. Topping off the cooling system is done through the coolant resevoir. When I emptied the system on my daughter's 2002, I pulled the lower radiator hose and then refilled the radiator through a funnel into the very small upper radiator hose, and then topped off the resevoir. That seemed to have covered it as I have not had to add any more since then.
open da hood. see the coolant resevoir? under that is the lower radiator hose. follow it to where it goes into the engine, and under that flange is the thermostat
Check the radiator hoses. The coolant is either leaking out of the new radiator, or it is coming from a radiator hose. The water pump may be leaking. Hose clamps may be loose.
A leak in a coolant system can usually be fixed by replacing a hose. If the leak is at the end of the hose, a new clamp might be necessary. If the radiator is leaking, the radiator might need to be replaced.
your thermostat is closed. needs to be replaced. inexpensive part but can save your engine from overheating.
Flush the coolant, change the coolant resevoir and add new coolant, it doesn't hurt to change the hoses either