Ive got a 2012 tfsi and when i was driving it all of a sudden the car started like misfiring. Ie car judders around 2k then goes but wont go over 4k. Ive had the aa plug it in and theres no error codes at all no lights on the dash. So i thought boost leak but its been checked out and no leaks found all clips tightened up. So i was thinking diverter valve?? If so how do i order the rite 1 without taking the othe 1 off first??

Tia

Forgot to say the car as been whistling like i have a dump valve for the last few weeks even tho i havent got 1 on

Not the same car but my 1.9tdi whistled away like yours and randomly went into limp mode. Actuator for turbo was sticking. Freed it off and it was fine since. Might be worth checking its moving freely and not jammed half in half out.

Alasdair

Rite i replaced the diverter valve reset ecu disconnected the battery for 10 mins checked the actuator and its still the same any ideas ??

I presume if it was a coild pack or plug it would show up a code ??