who adjusted it for you ? if you did did u use an offset feeler gauge ? was the mark on the cam gear at the required positions ? i know for sure that doing it without an offset gauge it's pure lottery. the first time i did it it came out sweet, the second time came out like shit and my engine knocks even worse that before. is the hollow noice inside the cabin ? or is it when the hood is raised and you are in front of the car. so many knocks can come out of an engine it's not even funny
