Finally bought my dream car

I finally bought my dream e39 although I wanted it in 6 speed but I am satisfied with what I got
2002 BMW 540i-m sport with navigation and sport seats sport steering wheel. 120k miles black on black, Everything is awesome in the car untill I go to the engine bay and I hear some knocking noise I called the previous owner he told me his mechanic said its a tensioner that needs to be replaced. Now I go and scan the codes on the car I get so many codes , camshaft sensor, vacuum leak, o2 sensor. I check and I realized that the cam shaft sensor was disconnected and the hose that goes to the big boot was broken so I fixed all that and replaced all the plugs which they were really bad and did an oil change, the car runs and drives so much better now but I still hear that knocking noise