hello everyone im new here and i recently got a 2006 audi a3 8p 2.0tdi quattro at first it just had an idle issue so the revs on idle would just go up to 1k and after some time would go back to normal then when i push it past around 135km/h it would ussually put the car in limp mode and after a restart its bakc to normal but when i woke up today went outside started it everything seemes normal i started driving got up to fourth gear accelerated and started to hear a knock but only while accelerating its similair in fifth gear as well have any of you had any similair issues?