A few weeks ago I posted about a whirling noise coming from my trans. Took it to BMW and the claim not to be able to replicate it. Since then I've noticed what seems to be the trans slipping but only under light throttle. Above 3k in all gears under light to a low medium throttle the car will shake and sounds like what I believe to be the trans slipping.
Now for the part that mind f*cks me.. Under full throttle it shifts perfectly. Did a 1st-8th WOT pull and shifted perfectly. The other day I did about 8 'Diagnostic' launch control launches from a dig and had no issues with shifts. Also, the Zf trans' are built pretty good and theres no way my X3 is close to making X5M power... Yet
Scanned the car and the only codes that came up will be attached in the picture.
Only thing I could think of is something to do with my wastegate. Under light throttle is when it acts strange. Perhaps this foolery is confusing the trans and causing it to slip?
I've tried to fix the wastegate but I fear I will not be able to get the vacuum line back on the the actuator and don't want to risk it. Car is going into the dealer on the first.