Well today I did a few tests with the expansion tank cap removed.
I drove two trips of 20 minutes, let the car cool a few minutes and then removed the expansion tank cap.
If I let the car idle, the coolant level keeps rising and rising until it over flows.
Furthermore, I was about to try another combustion gas test but as you can see in this video
https://youtu.be/jCwu8ZkSlUM
There are bubbles (seen in the tester even though I am not sucking in air) and pressure in the expansion tank.
I am wondering if I need to buy a cylinder leak down tester at this point as I am thinking it is pretty confirmed.
Opinions ?
Thanks again
Martin