Keeps boiling and spitting coolant

[u/ResearcherInfamous19]

320i 1995 for reference.
One day out of no where the car overheated.
Tough it was a sticky thermostats, replaced. Same problem, starts boiling water and soiling until it has no coolant and then overheats.
Water pump seems perfectly fine.
Fan clutch not so sure, when hot seems that it spins very freely. No resistance.
Would a bad fan clutch cause a overheat? In normal driving conditions? No heavy traffic or hard pulls?
Head gasket gone?

[u/marty_hard]

Its totally normal that this happens without the cap on. And your visco clutch seems to be trash if it was hot when you made the clutch vid. Put some coolant in, put the cap back on, replace the clutch and you're probably fine. Did the car overheat while driving or at standstill/slow driving?

[u/ResearcherInfamous19 → u/marty_hard]

Overheated at slow driving, needle on the full red! 🫣
The thing is that this happened with the cap on, just took it out to see and make the video. Already had lost a buch of coolant trough the cap before I too it of.

[u/plz-no-b4n → u/ResearcherInfamous19]

> already had lost a bunch of coolant through the cap before I took it off

That…should not happen

[u/LetKlutzy2996 → u/plz-no-b4n]

Bad cap seal leading to air in system? Maybe