I finally got it all done but have a problem. Driver side front strut makes "popping" noise intermittantly. Did I screw up when I compressed the spring and installed the strut mount? I thought maybe something just loosened up, but rechecked all the bolts and they are tight. But the top cap of the strut assembly (in the engine compartment) actually can spin, so I know there is no pressure on it. Can anyone tell me where I went wrong?