[wodorof]

i afraid that someone tampered with cooling system and presence of air is the reason why pump is so loud....
can you tell me the best way to bleed the system? if i need use vacuum , there to connect it?

[audi666]

Do it as i told in previous post and you will have no air in the system.
Even if you have 2.7 TDI (180hp with no aux. pump, Euro4) same if you have 2.7 TDI (190hp, with aux. pump, Euro5).

Run engine at idle untill it arrives at 90 degrees with coolant tank cap off.
When it arrives at 90 degrees turn on ventilation (with AC OFF, or ECON enabled) from climate control at MAX (13-14, i don’t remeber exact) and put temperature at HI.
At first, it will blow cold air, but in a couple of minutes will blow hot air and the coolant level will go down.
Keep adding coolant untill the level in the expansion tank is stable.

[danis11]

If valves are stuck in close position, vacuum won't help.
You need to make sure the valve works. The circulation pump is activated through diagnostics, but it is not recommended to activate it for a long time in vain. Valves are a disease on valve systems.

[Dana]

So if the car has now been moved and there is still air in it, I assume that the unit is defective.

Unfortunately, I haven't found the TPI yet.
What model year do you have?

[wodorof]

[SOLVED]
As you said there was air in system, also in the electric pump
after careful bleeding the system everything works as it should