Audi A3 Coolant loss

[maksta]

I have an Audi A3 2.0 TDI 2014 with 43,000 miles on the clock. Have experienced low coolant warning on dash and have had to top up coolant over the last few weeks. Took it to an Audi specialist, they pressure tested it for several hours, found non leaks, and replaced the plastic reservoir.
Unfortunately this didn't stop the problem. Still have the warning on dash and have to top up reservoir.
They gave it another pressue test, and failed to find any leaks.
We agreed on replacing the egr cooler, which when they got to it appeared to have coolant staining.
This cost a lot of money and again unfortunately the problem remains, warning light and topping up reservoir.
The garage has now suggested removing the head, pressure testing it and replacing head gasket. Then re-fitting old head or new one if it fails test.
Has anyone done this already, and did it work??

Many thanks
Maksta

[TC7]

Did they also replace the cap on the plastic reservoir as well as the reservoir itself? A leaking/faulty pressure cap would explain why the pressure tests dont reveal any leaks, yet when the cars up to temp could be boiling the coolant out the cap.

[maksta]

Yes they did thanks

[GreenV8S]

maksta said:

they pressure tested it for several hours

Hot and/or cold? If there's a leak, it could well be temperature sensitive.

Removing and replacing heads without first proving a fault seems bonkers, unless they're proposing to do it at their own expense and risk.