When I drove home after a long trip, I noticed the car was making bubbing sound. When I popped the hood, I saw the coolant tank was filled all the way and some coolant overflow outside. I took the coolant tank hose off and saw steam jetting out of the hose. When the steam get weaker, I put it back inside the tank and started the engine then rev it to about 3000 rpm for a few seconds and shut off. The engine sucked all the coolant from the full tank back inside. Is it normal? I haven't seen it doing that before. Car has about 320k mi
when you pulled the hose off (be careful you can scald yourself very badly!), you depressurized the system and and hot coolant suddenly vaporized. This isn't good for the engine.
As the engine cools, it's normal for coolant to be sucked back in.
But I would worried about the coolant bubbling and overflowing in the first place. It means things are overheating. When a car overheats, you should stop the car, leave it running, and turn your heat on full blast until it cools down. Don't shut it off right away.
https://www.youtube.com/watch?v=evpaTW2WJ5Y
You are lucky that you didn’t burn yourself. Never open on the cooling system when the car is warm.
Regarding the issue you have, if you use correct coolant, you may low pressure on your coolant system. Change the radiator cap and pressure test the system to make sure you do not have any leak.
