Hello all.
My vehicle is a 2005.5 s4 with the tiptronic transmission. I’m currently at 116800 miles and have been having some drivability issues. I have rpm fluctuations of about 200 rpms and a vibration at the bottom of the rpm dip. It sounds like I’m driving over rumble strips. I also hear a slight squeak as the engine reaches the bottom of its rpm dip. The transmission has started shuddering (best word I can use to describe it).
I changed the fluid and filter and there is still no change in drivability. I’ve read that this can be a torque converter issue. I did some logging of the torque converter slip and placed markers when the transmission did its rumble. There was increased slip when the car reached the low point of its rpm dip. So this is as far as my knowledge goes. I also logged the car and there were absolutely no misfires. Is there a way to help identify the exact problem and to isolate it from transmission/TC?
Any ideas where to look next? I’m ready to trade this thing in! HELP!