hi guys i have a 2003 mcs and i lowered it with a sport suspention kit from H&R it looks great but i have a bump noise when i go over the speed bummps, i have replaced all the lower conrol arm bushings. what can it be i was looking and thouight can it be the sway bars that need to be replaced since the car is lower or the links? please need help thank you

 

Here are a couple things to check:
1. Make sure the top strut bolt is actually threaded all the down and just did not torque tight on a bad thread. If the top nut is not torqued down properly the spring can rattle in the perch causing a noise over bumps. Look at the amount of threads showing on left and right struts (left/right front and left/right rear) to see if they are the same. If one is different that could be an indication that one nut is not threaded completely. You can also jack up the car and give the spring a good tug to see if it moves in the perch indicating that it might be loose.
2. Check the sway bar end link nuts to make sure they are tight.

 

All of that is tight. Can it be the sway bar rubber mounts?