Apexy55

But as soon as I squeezed them bubbles out after turning on the ac, the noise when the ac was on, was much quieter, almost impossible to hear but definitely no sound with ac on.

Just tried with ac on and the noise goes away. I opened the expansion tank and after squeezing the hose, a couple of bubbles popped up. I turned the ac on again and set it to max temp and speed, see if it circulates the coolant. Later when I get home from work I'll open it up again and see if more bubbles pop out.

Also the sound cannot be heard from the engine bay, tested it earlier with a friend and we could only hear it inside the car. For information it's a 2016 CRMB engine although the vin says its a 2017 model, is that normal?

Hey everyone, my octy started doing this weird pulsating sound after doing a timing belt and water pump change and I first noticed the sound when it was doing a dpf regen. I asked the mechanic who did the change if he knows what's going on and he has no clue about that sound, but can definitely hear it. I'm wondering if any of you knows what this sound is. Thanks Video of octy