I recently bought a Cayenne Lumma wide body 4.5s and guess what? It's developed that knocking noise we all talk about. Porsche suguest another engine. That sounds a bout right. 12000 car needing a 10000 engine replacement. Not sure I will get my money back on this one haha. I have just had major service and he said it was crack in cylinder. The ticking I can cope with but it looses power quite alot when warm. I was hoping there would be some kind of filler you could pump into system like on radiators. That goes to show my mechanical capabilities. The other noise is a knocking down at the right hand side, like a track rod or something. The **** who serviced it said they had put wrong spacers in and they were not sitting correctly on hub. BOLLOCKS. If that were case why would it not make noise all the time. It seems to make it when you set off quickly. Any ideas. My only thought was that we all met up and built one good Cayenne out of all of ours? Let me know if any ideas about knocking. Good luck with all your cars. Simon. God bless. P.S I only run mine on high octane expensive fuel and oil and its gets through alot of both. At moment I am getting 11mpg. Good oil should always be used, but should I go back to normal cheap octane?