Just purchased a 2015 TDI and 2 days ago with 1160 km on a cold engine I started getting random engine fluctuations and the tachometer was jumping from 600 to 900 RPM. I pulled over and with my foot on the brake, I started videoing. Engine temp was just over 50c and no engine light came on. After a few minutes and as the temperature increased the issued stopped, but given the newness of the vehicle I took it to dealer with the video. They claimed that they had never seen this before. I left the vehicle with them and they couldn't find the issue. Has anyone else experienced this?