Hear boiling sound after shutting the engine down

[Tony_1992]

Recently I heard a weird sound, and it comes from the engine bay. It's like some fluid is boiling but the water temperature is always normal.
This sound occur every time I drive for a middle distance and shut the engine down.
At first I thought it was the lack of coolant and after adding coolant to the degas bottle to max level, the sound is still there.

Does anyone have idea what causes that sound?

 

[grizzlyls]

Not a tech so just 2 cents, but when I had tstat troubles it was the coolant boiling and too hot. It likely means the system isnt pressurized (leaks) right. Mine turned out to be the Gen 1 alum tstat cap wasnt sealing right. Once I figured that out, no more boiling.

Are you using and OBDII sensor and an app to read temp? Gauge means nothing. If your are using these, and the temp is reading below boiling, then you are right its not the coolant - but I bet if you are not you will see it is boiling temp ~220.

 

[AmsterDutch]

Recently I heard a weird sound, and it comes from the engine bay. It's like some fluid is boiling but the water temperature is always normal.
This sound occur every time I drive for a middle distance and shut the engine down.
At first I thought it was the lack of coolant and after adding coolant to the degas bottle to max level, the sound is still there.

Does anyone have idea what causes that sound?

Have you tried to bleed the cooling system?

 

[joegr]

The sound is air from the engine coolant loop bleeding into the degas bottle. You should never have to add coolant. You have a leak, probably many leaks. Just because the gauge doesn't go past the half-way mark, doesn't mean that the engine isn't marginally overheating. It has to get well over 230 F before that gauge starts moving again.
When was the last time all the plastic cooling system parts were replaced?

 

[HMass1]

I've had the same exact issue. If your degas bottle (coolant reservoir) is extremely yellow and old looking I would advise changing it as I did. Some cracks may be hairline cracks that are very tough to see. Mine had multiple cracks underneath but I couldn't tell until I removed it. Good luck!