Hi, a request for help My brother in London has a 2.0l TFSI A3 Quattro 2006. He is complaining of a regular knocking noise coming from the cylinder head and using a screw driver he has narrowed it down to the gearbox side of the head. He has all ready replaced the cam follower for the high pressure fuel pump and it showed no signs of excessive wear. He is fairly familiar with cars and says that it is a knocking noise rather than tappets or the sound of a loose cam chain. He has asked me to send him some Elsawin pictures because despite some knowledge he is not familiar with the TFSI engine and the additional lumps of metal stuck on the end of the cylinder head (gearbox end). From the elsawin picture attached #9 (Exhauster pump) and #17 (Housing) he is unfamiliar with. So, number 17 is the housing for the high pressure fuel pump? And what is an exhauster pump and what does it do? And could any of these result in a knocking noise? Also, for my benefit now, what is part #4 described as valve housing? is it part of a PCV system?