tablahan

My friend noticed that my CLK230 needs a little topping off on the radiator. Obviously he opened the radiator cap to see this. Now i used to own BMW and they said that i should not open the radiator because air bubbles come in....

Question 1. Does this apply for the CLK as well?
Question 2. If it doesnt apply and i can open the cap myself can i top off my radiator with water or must i use antifreeze?
Question 3. If i cant open my rad cap because air bubbles will form how do i remedy this do i have to take the car for service?

Thanks in advance!

mbtech208

The cooling system on your car is a self-bleeding system. This means the cap on the expansion tank is the highest point in the cooling system, so any air in the coolant rises and escapes through the cap. You can open the cap and top off your coolant without any special procedures. If the level is just a little low, just add water to bring it back up.