Have you had any luck finding the root cause of this yet volrem , ive just had a 2010 galaxy with the same issue , I replaced the clutch and damper assembly car was perfect so being curious I disassembled the old unit and found some of the springs stretched and both the clutch packs badly burnished.
The vehicle had done 50000miles without the fluid service.
Danny
hi volrem, sorry if I'm late, I think isn't a problem from automatic transmission, those engines have got a problem with turbo' s VNT. It usually don't work fine and create a against pressure through EGR valve with a pulsed wave.
If you want to do a test disconnect EGR valve or plug it and test the car.
But you rember the problem start from turbo and not from EGR valve.
Regards.