Over the weekend I adjusted the valves in my sons 735i. It has an m30. Discovered that one of the banjo bolts was loose and laying on the top of the head. Looked carefully at the cams and checked all of the valve clearances. Only found two valves that were a little tight and readjusted those. Reinstalled the banjo bolts with new aluminum washers and a bolt locking retainer. Have run the car several days now and there is still too much clatter. I have an m30 in my 89 535i and there is less clatter from this engine. What do I do now?