superb 2016, 2.0 liter ea888 engine 203k KM
a little backstory of what happened.
i had waterpump failure, towed the car to my mechanic.

the mechanic suggested replacing the whole coolent system because everything was old and i agreed as i want the car to last long.
he replaced these items:
main waterpump
heat pump
auxeliry water pump
coolent tank
all the hoses
coolent.

next week my radiator cracked and got replaced too.

in another words the whole system got re-newed :)
he said coolent should lower for about few days because of all the air and stuff after he replaced the radiator and did a pressure test (that i didnt see what he did exactly).
it has been 2-3 weeks from my last visit, the coolent WONT STOP GOING DOWN!

no leaks under the car, i even replaced the coolent cap because i heard some people said it helped.
i got no headgasked/engine block problems from what the mechanic said
do someone got a hint??? its driving me crazy and i cant get any ideas.

i adding some pictures from the repairs and such

Did your mechanic follow the correct procedure to bleed the air out of the system? You need a VCDS or similar to do this. It opens and shuts various valves in sequence during the refilling process to purge the air.

When I had my water pump & cambelt changed by an indy they didn't do it properly and it took a couple of weeks of daily top-ups before the system finally stabilised.

Edited 5 November, 20255 Nov by Gammyleg

30 minutes ago, Gammyleg said:

Did your mechanic follow the correct procedure to bleed the air out of the system? You need a VCDS or similar to do this. It opens and shuts various valves in sequence during the refilling process to purge the air.

When I had my water pump & cambelt changed by an indy they didn't do it properly and it took a couple of weeks of daily top-ups before the system finally stabilised.

My mechanic doesnt use VCDS but i do have one of my own, how i can do it? Is there a guide?

36 minutes ago, Gammyleg said:

Did your mechanic follow the correct procedure to bleed the air out of the system? You need a VCDS or similar to do this. It opens and shuts various valves in sequence during the refilling process to purge the air.

When I had my water pump & cambelt changed by an indy they didn't do it properly and it took a couple of weeks of daily top-ups before the system finally stabilised.

Oh nevermind about my last comment i saw there is a guide in youtube, thanks for letting me know!

1 hour ago, LinoTheFox said:

Oh nevermind about my last comment i saw there is a guide in youtube, thanks for letting me know!

Good luck. I hope it fixes your problem.

11 hours ago, LinoTheFox said:

My mechanic doesnt use VCDS

How did they bleed the system then???

How much is the coolant going down? Say 1L per 1000km or what?

A small amount not a big deal l, but....

If you have an air pocket and it was in the wrong spot, you could crack the head or damage the head gasket.

If its been a few weeks and it's lost alot of coolant Id be looking at the head gasket and head.

Needs a pressure test and Co2 test of the coolant by a guy other than the one who didn't bleed it. He's not likely to admit his lack of expertise lead to the cracked head.

You may be lucky and just have a leaking egr or air in there still, but definitely bleed it before you drive any more

And get a mechanic who can do the job rightly

check the stock plastic version which is siutated at the back of the engine as it prone to fail:

Edited 6 November, 20256 Nov by Awesam

22 minutes ago, BlueWagon said:

How did they bleed the system then???

How much is the coolant going down? Say 1L per 1000km or what?

A small amount not a big deal l, but....

If you have an air pocket and it was in the wrong spot, you could crack the head or damage the head gasket.

If its been a few weeks and it's lost alot of coolant Id be looking at the head gasket and head.

Needs a pressure test and Co2 test of the coolant by a guy other than the one who didn't bleed it. He's not likely to admit his lack of expertise lead to the cracked head.

You may be lucky and just have a leaking egr or air in there still, but definitely bleed it before you drive any more

And get a mechanic who can do the job rightly

i will do state that the coolent stopped dropping after yesterday run after i posted this, it didnt drop at all.

first of all my superb doesnt have bleeding function in VCDS i checked this morning, we bleed the system by pumping manually the hoses and addidng coolent, then running the car unit the thermostat opens and letting it run in the garage for about 20-30 minutes.
second, i did turn the heater without A/C in my car to bleed the pipes in the heater today while going to work and coolent level rose up now.

seems like its all bleeding that took a lot of time, plus probably the cap probably needed replacement.

today i will have another 2 hour drive, and i will keep monitoring the system and see coolent tomorrow morning

10 hours ago, Gammyleg said:

Good luck. I hope it fixes your problem.

well vcds doesnt have for my superb the bleeding function :\