It seems like my car is going through coolant like crazy! There is no leak and no white smoke coming out of the exhaust. The car doesn't over heat, in fact I haven't once seen it go over normal operating temp.

Anyone have any idea what might be causing this?

And I have an aftermarket 1/2 size radiator if that helps.

 

Either it's leaking, or it's being burned. It doesn't just vanish.

 

I know that I just can't find the cause anywhere. I've checked all coolant lines and there is no leak. I haven't seen any white smoke. I just don't know. My radiator always seems to be topped off but my coolant tank goes empty within a week or two.

 

check all your coolant lines and heater hoses for leaks and coolant stains, and also floorboard in case the heater core is leaking. If no leaks then it has to be burning it. Be sure to check underneath and not only from the top of the engine