GM AT slipping when cold .. ( GA6L45R ) BMW

[Ndx]

Hello,

On cold days my transmission seems to be slipping ..
Car moves forward but its not accelerating RPM's go up but speed dosen't change.

This last for 0.5Km +1.5 minute of driving and it getts better.

Its only when temperatures drop 0C or below 0 ...

Car has only 25000K Km ( Out of warranty )

I flushed transmission with DEX VI ( BMW OEM )

I tried to overfill it a bit still no luck ...

Should I try changing oil to Amsoil or Redline D6 ... better flow in cold ?

Any other ideas ?

Thx

 

[SteveSRT8]

Has the pan been dropped and the filter changed?

Dex VI is a new formula and has excellent cold flow properties, so I'm sure that is not the reason.

ANY slip is extremely bad, and if it happens when cold the likely cause is low fluid level. Next is all bad...

 

[Ndx]

No it wasn't replaced ... on 20k Km i was thinking its to early to do it ..
Its not low ..

There is no dipstick so you fill until you can with car running ... and thats what I did ...

Thx...

 

[JGW]

Same exact situation as me. I let the car sit for a month, and the transmission was as good as new.

 

[Ndx]

I wish ... but I can't see how this could fix itself.

 

[JGW]

Me either. I have no idea how it happened, but it did.