i just put a 2012 engine in my 650i because the other one had a knocking rod bearing. this one sound good and rev good but if i put the idle low it start to make that noise. maybe timing chain?? that engine only have 1000km
i checked the 2 timing chain tensioner and they are almost all the way in so the timing chain its not stretched. could it be the valve??
i play with the idle knob to make the noise go and back.