2006 Mini Cooper S automatic transmission problem
 

Hi my 2006 Mini Cooper S auto transmission seams to slip going into 3rd gear high rev then bangs into 3rd after letting off pedal after the car is warmed up. I changed the transmission fluid and it did not work. I am being told it is a pressure issue. Whatever that means.
Can I put an additive in the transmission to seal the pressure?
Do you think that would work.

Hello and welcome to the Pelican forum. Did a shop diagnose the issue? What shop (MINI certified?) or was it a dealer? Does it do this when the vehicle is cold as well or only when it's at operating temperature? How was the fluid level when you changed it? Are you sure the fluid level is correct now? I've seen issues with hard shifts before relating to transmission fluid and once it was changed and they readapted the transmission it shifted fine. Are there any faults for the transmission in the system?