Hi guys, I have a 93 SC400 and for some reason when the radiator needs coolant it doesn't pull it from the reservoir, in fact every 1 to 2 months i need to add coolant thru the fill plug in the front of the motor. Because if not it starts to over heat due to lack of coolant but the reservoir has coolant. What could it be?
Thanks:

 

hmm....clogged or broken line to the bottle?

As far as overheating though, just to be safe, you might want to check out your thermostat and make sure you don't have any leaks in the system.




BTW, please tell me you meant that you add coolant to the radiator, NOT the engine!

 

The thermostat was the 1st thing i changed once i noticed the problem and the system doesn't have any leaks.

 

You're positive there's no problem with the line to the bottle?

Is your radiator cap working properly?

 

That's one thing that i haven't checked the radiator cap.