I do have e90 320d lci 177hp steptronic, and ive noticed that my rpm fluctuate while giving a bit of pressure to gas pedal (accelerating veeery slowly - just when you fell you make your car work instead of coasting. It's about 200rpm up and down, not spiky/junky, just slowly fluctuates. It does not jerk nor fluctuate during idle, only when driving between 25mph-50mph. Didn't lose any power, fast as always.
Is there anything to check before transmission? If it is torque converter should I go for new or rebuild one?