Most people think that the M104 cam sprockets have no marks but in a way they acutally do. There are holes on the backside of the sprockets where you insert a pin or allen key so that the hole is flush with the valve cover machined surface. Facing the engine fron the front the proper reference would be the exhaust cam hole @ 9 o'clock and the intake cam hole @ 3 o'clock keeping in mind that these holes are on the backside of the cam sprockets. This information is available in ALLDATA.
Once again set the pins to reference the cam sprockets with the crank at TDC. Also make sure that the camshaft timing advance is contacting from the direction of rotation. In other words the intake cam is turned so that the variable valve timing slot is being pulled in the direction of engine rotation which in this engine is clockwise. Now remove the pins and turn the engine clockwise to take up any slack in the chain. Always do this before installing your timiing chain tensioner. Failure to do so can break the timing cover when screwing in the tensioner.Turn the usual 2 rotaions and double check that all is lined up properly. I hope this helps! Good luck!
