Bubbles in antifreeze

Hi GordonLondon, thank you so much for your help. The reservoir has no pressure or back pressure, the hoses connected to the reservoir are in good condition, and there's no antifreeze leak; the level is correct. I'm going to flush and completely bleed the cooling system and replace the pressure cap (not the reservoir cap). I'll let you know how it goes. Thanks for your attention.

Hi Hodei, I really appreciate your help. The reservoir isn't building any pressure or back pressure, the level is correct, and the hoses connected to the reservoir are in good condition. What I'm going to do is bleed and flush the entire cooling system and replace the pressure cap. I'll let you know how it goes. Thanks, Luis.

Hey Diegui, thanks for your help. The coolant is just bubbling in the reservoir, the level is fine, the compression is correct and even in all cylinders, the hoses connected to the reservoir are in good condition, there are no leaks, I don't see any white smoke from the exhaust, and there's no oil or water in the reservoir or on the dipstick tube. I'm going to bleed and flush the whole system. I'll let you know how it goes. Thanks a million. Luis.

Dude, it's really simple...it's the radiator cap, the sealing valve or the seal is bad and it's not holding internal pressure and it's diverting it to the coolant reservoir...that's it...let me know what happens next.

Dear friend, the solution was simply bleeding the coolant system. Thank you so much for your help. Thanks, Luis.