iono about your knock noise... but my i think i have the same problem as your. but i got to work. its my egr valvue pipe that came out from the egr to the egr cooler. that one like a h shape thingy thing. i got air leak right there on the two bolt that tight the egr valvue pipe to the egr cooling tho. hope the same for you. how do i know it. i shut my engine till the motor is cold. n i start at cold n put my hand around it to find out if i got any air leak. and i found out that there is a air leak. and now i got turbo on my mk2 so i decide to block my egr valvue so now i dont have egr no more. so hope this work for you alright. let me know how u get to work alright.
