I flushed my radiator per instructions on the can of flush. Now I get a blinking low-coolant-level light about 2 minutes after the engine starts...I'm guessing the engine's warming, the thermostat is opening and causing the light...due to an air bubble? The reservoir is full. If there *is* and air bubble, can I bleed it out somewhere? Can I park my car at an angle in a ditch to make the reservoir a much higher high-point, hoping the bubble will escape? Engine temp is normal. Any thoughts?