2004 G35x - Driver's side front suspension knock/rattle
 

Hi all,
This is my first post, so be gentle :)
My 2004 G35x has developed a slight knock or rattle noise in the driver's side front suspension. It happens mostly when I initially drive the car in the morning and is much more apparent when it's colder. It's very noticable over small bumps or cracks. Typically, it becomes harder to hear and seems to go away after driving for a while. It also seems on warm days that the noise is practically inaudible.
I replaced the compression rods and link pins about 25k miles ago. I replaced the stabilizer bar bushings about a week ago. I have KYB struts, which I installed about 25k miles ago also. I have checked all bolts and everything is tight, including the strut mounts and strut center nuts. No luck. Didn't notice any movement in the lower or upper control arm ball joints when I used a pry bar. The only item I haven't been able to check is the ball joint the link pin attaches to on the lower control arm (about halfway along the arm). Any thoughts? Thanks for the help, fellas.

check the bolts that go into the upper A arm, located next to the strut. if they are loose, they will cause a knocking sound

Thanks for the reply. I did check these already, but I only used a wrench so probably didn't get best torque on them. It was cold this morning and the rattling was much more obvious. I'm wondering if it could be the strut mount, as others have.

Could be compression rod bushings again, if you replaced with factory parts 25K ago.

Yeah that wouldn't surprise me. I bought them from Riverside Infiniti. You would think there would be some kind of warranty on those things. Bit of B.S., if you ask me. Thanks for the suggestion!

Probably smaller chance, but could also be a bad strut. I had a bad Tokico strut make a bit of rattle/clunk upon going over certain bumps. Initially thought the top nut was loose, but it wasn't. When I took the strut off, the rod was making a definite clunk when it reached the top end of its travel out of the shock body.

I have wondered about the strut. They can be affected by warm/cold temps. Guess I would need to take it out to make the determination, though. The rattle does sound like it comes from around the strut tower, but I know these kinds of noises can kind of "travel" through the bodywork/subframe and appear to come from another location. I also wondered about the strut mount itself but, once again, I would need to remove and disassemble the strut to see whether it was worn out.

Well, I changed out the strut mount on the driver's side. No dice. :(
Looks like it's probably the compression rod. Gotta love it!

You've got PM

Did you ever find the problem? It sounds similar to the noises I started hearing a couple weeks ago. Sway bar endlinks seem to be a common noisemaker on these cars so I ordered some new ones. They are cheap and easy to replace so hopefully that's all it is.

If not, I'll go ahead and order a poly bushing kit and start replacing them all.

Nope - just dealing with it for now. I've been too busy to work on it lately. I replaced the endlinks pretty recently so I'm pretty sure that's not it. I have an old compression rod that I think I will throw in and then check if the same noise occurs before buying any more parts.

Well, I went to change the compression rod with one I had lying around so I could test if the rattling noise still occurred, and I noticed that the lower control arm ball joint is leaking grease. I hadn't noticed this previously, but it makes sense that it was probably on the way out. I ordered a set of ball joints and hope to get them in soon. Not sure if it's worth trying to install them myself, since I'd need to buy a ball joint tool. Guess it depends on how much the local shop will do it for.

rent the ball joint press and 'pickle fork' from AutoZone or Advanced Auto.
I'm looking at doing this same thing in a week or so. Good luck! Let us know if that fixes the clunking.

Argh.. I tried to do the ball joint myself this weekend, but gave up because I couldn't get to the ball joint very well. I can see how it would be fairly easy on a non-AWD car, as once you disconnect the lower control arm from the knuckle you can kind of "swing" the whole assembly away from the control arm and get to the ball joint. Unfortunately, with the X, you have the driveshaft to contend with. I was hesitant to pull it too far, as I didn't want it to pop out of the front diff. True, I could have remove the driveshaft from the hub etc, but I ran out of time. Looks like I might have to bite the bullet and have a shop press them in.

Hello all - I had the ball joints pressed in, and, in the process, discovered the hub bearing on the driver's side was shot, so I had to have that replaced also. I get the car back, go for a drive, it feels great. Much tighter and much more stable on the highway. I didn't hear the knock/rattle sound, so I was happy that the problem was gone. Next morning, I start driving and notice the mother@#$%ing noise is still there!! Anyway, long story short, that night I pulled out the compression rod. The dust cover on the ball joint end was destroyed. I installed the old spare I had lying around. NOISE GONE!!
After all that, it was the compression rod AGAIN. I feel stupid to have given it the benefit of the doubt. Oh well, I guess 30k miles is too much for these things. Lesson learned.