I finally found what was causing the rattle at idle.The the top gray engine cover was vibrating at the oil fill neck tube.I put a zip tie around the filler neck,screwed on the oil cap back on,and no more squeaky vibration.For some reason after the engine was hot,the cover was a little loose by the oil fill cap.All the fasteners were on tight,just a little loose by the oil cap.Good thing for zip ties...

 

My i5 does the same vibrating crap. I tightened the clamps on the intake and that helped some, but it still makes that annoying vibration.