overheating

2002 Civic. Does this have a closed cooling system like the early Jeep? Seems to be losing coolant slowly. Not receiving coolant from reservoir. Don't see a leak anywhere. Shop has given a couple of explanations but hasn't been able to fix the problem.

So the car overheats?? Was anything recently changed on it such as the radiator or the thermostat? I'm thinking thermostat needs to be replaced but that should have been your first guess. You said you loose coolant but you dont a see a leak. Also I would say there is air in the system and to open the radiator cap, turn the heat on high, and let it run while you keep topping off the coolant. Some hondas had a bleeder screw right at the head to blead air out. Having an air bubble in the system can cause overheating. What suggestions have you been given? Are you sure there isnt a little rupture in the hose from thermostat housing to the back of the block? Also how is your oil level are you low or loosing any oil?

Radiator and reservoir were replaced after an accident. Thermostat was replaced three weeks ago. Also told there was probably air in the system so it was bled but no change. Seems like we should see some change in the coolant level in the reservoir but it does not change.

Perform a pressure test as well as check your water pump and hoses. No coolant no leaks hello head gasket.

Shouldn't the radiator pull coolant from the reservoir tank also?

Shouldn't the radiator pull coolant from the reservoir tank also?

Reservoir tank is an overflow and only gets connected to the radiator when there is enough pressure builtup in your radiator. But if there is an internal pressure loss, such as head gasket, like BrodyP said, it will never open. If you don't see any external leak and the coolant is not showing up in your oil, then I think the head gasket sounds convincing.