I have a 2008 model with a knocking noise as described in this thread. I have read many threads on these forums about steering column/intermediate shaft related knocking issues, and this thread matches my situation almost exactly. And that is...I have had the intermediate shaft replaced and that solved the dull clunking noise when turning at low speeds, but I am still left with a rattle (or double-knocking) when going over bumps at medium-to-highway speeds.
The rattle sounds like it is coming from right in front me, right behind the dash - like behind the odometer. It really sounds like it's coming from inside the car, not outside. I know how sound can travel, but still, it's really strange.
The original intermediate shaft diagnoses seemed to make sense, as the knocking (as well as the clunking) was just the sort of noise you could imagine a problem like that causing, and in the right area! I've had strut and tie rod problems on other cars, and it doesn't sound like this.
It happens most at medium-to-highway speeds, so mostly when going straight or straight-ish. But even then, it doesn't do it all the time. I can drive to work at it won't do it at all, then I can drive out at lunch and it will sound like there's something seriously loose! Or vice versa. It can even just start in the middle of a journey. Hot or cold doesn't seem to make a difference.
I did some more research online and found various tie rod and sway bar possibilities. I asked my dealership to check those out and they said it was nothing like that. They found the battery box was loose so put it down to that - but of course that wasn't it either.
The thing is, it doesn't do it reliably, either when I take it in to the dealership and road test it with them, or when they do some work and then road test it afterwards. So it's easy for them to think they've solved the problem when they haven't. But I do 500 miles week, and it does it enough for me!
I'm wondering whether my dealer didn't check the tie rod or sway bar possibilities very diligently? I'm also wondering whether tie rod or sway bar problem could really sound so much like they are coming from inside the car? Or are there any other possibilities.
I even have a sound clip of the noise - http://tinyurl.com/c352mk6
(ignore the general noise, listen out for the rattle).
Has anyone got any advice or ideas? Thanks in advance.