Overheating issues
It's a really cheap and easy way to start eliminating possible problems.
In a normal situation: the coolant will expand as the system heats up and coolant will flow to the bottle and as the car cools down, the coolant contracts and that excess coolant is siphoned back into the radiator.
In your situation, something is causing pressure to move from the radiator to the bottle after the car is shut off and for that process to "burp". Perhaps this is due to some heat sink after the car is shut off and you have gas in the system?
I would first let the car cool down and then open the radiator for a check. If the fluid isn't up to the top, then the first thing to do would be to get a pressure test.
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When you shut the car off, the residual temp increases as the airflow and coolant flow stops which increases the pressure in the system. If the cap is weak it will let it bypass out into the coolant tank/ground.









