I do have stock suspension. I am actually going to get new springs tomorrow. I was reading up a lot online and it seems like the bolts on the sway bar come loose. So when I get my springs installed I will point that out. If not I will take it to the dealer. Its still under warranty. The springs I ordered are the FRPP K Springs.
Take a look at your struts, see if you can see any oil around the shaft, if you have a spring compressor you can try taking off the springs and see if you strut still has the gas charge in it.. If it doesn't, then your struts are bad..
Generaly if you lower your car you run a strong chance of junking the stock struts, thats why most go with after market struts when lowering.
Ive even heard of new cars that aren't lowered having bad struts, normaly you don't hear it with the factory mounts though..
I had the same problem, had a ford tech tell me the sway bar nuts were notorious for backing off. I put lowering springs on the car and must not have tightened the nut down enough. In my case, i think the nut backed off and there was excessive stress on the threaded portion of the sway bar linkage and it snapped off. once the nut and remaining portion of the threaded portion gone my sway bar sags on that side of the car, thereby rubbing on the lower A-arm and producing the knocking sound.
Here is a pic with the wheel still on of the snapped threaded portion of the ball joint on the sway bar link.
Ya definitely check your sway bar nuts. I had that problem on my old 2006. They would just like to back off for some reason. Make sure when you tighten them to get a wrench on the stud and then tighten down the nut.
I got under the car last night and it was the right side lower sway bar nut. It had backed off so much that I could twist it with my fingers. I torqued it down nicely. Sound is gone. Glad it was something simple. K Springs going to be installed Thursday.
I wouldnt let it get to the point where it broke. Its not that hard at all. Just take your wheel off and its the nut where the sway bar connects. Took me like 10 minutes with a jack, two jack stands and an adjustable wrench.