Opened hood to add wiper fluids noticed engine was shaking a bit much! Don't know if it's normal or something to do with motor mounts but only while I'm sitting at the red light can I feel the car shaking.. I'm still at 650 rpm while sittin n no major difference in driving! I did recently do a spark plug n boot change noticed a vacuum line kept easily coming off the 3way connector ,but i taped it up pretty good to ensure Air wouldn't get thru! Any ideas or suggestions??