Ive had my 04 350z MT for almost a year now. Got it with 85,000 miles very well kept. Im the 2nd owner.
Have been replacing parts here and there as this car will be for my son in a couple of years. Slowly been replacing suspension parts along with other parts.
I installed some Tein Basis coilovers a few months ago along with some white line bushings in the front, compression rod, front and rear end links, front strut top hats etc... I have been getting some knock/popping noises in the front suspension on both sides. Mostly under very slow speeds or coming out of the driveway.
Just by using an impact gun will the top hat nut get tighten enough? At first when i installed the Tein coil overs i used the impact gun to get the top hat and nut on out of the car. Then after a few miles i used the impact gun again to tighten the nut but this time the struts were on the car. Is there a possibility that this nut on both sides is still lose and causing the popping noise in the front? I will be installing some new ball joints in the next week. Ive tried to replicate the noise while under the car but can seem to find where its coming from. Ive also re-torqued the suspension nuts/bolts in the front. Car rides great and there is no abnormal tire wear. My next step is doing the ball joints and removing the coilovers and re tighten the top hat nut. Any suggestions?

 

Once the struts are on i dont think you even need that nut anymore so i wouldn't put my money on that being the issue.

How much thread did you leave showing? If you tried to make the front too low you might be hearing the spring moving, i threaded my adjustment about 3/4 inch give or take never had an issue..

 

to be honest im not sure how much thread i left showing. This popping noise was already present when i bought the car which still had the stock suspension on. I thought with the new stuff the noise will go away which it kinda did at first but started making it again. Still a few things i would like to replace before considering the steering rack like upper control arms, inner/outer tie rods have.

 

Inspect your sway bar bushings and end links. Usually the popping is either the compression rod bushings (especially on lowered vehicles) or inner bushings for the LCAs. Depending on how much you lowered the Z on the Tein Coilovers, you may need to get adjustable end links for the sway bar. I know you said you replaced these, but did you replace them with OEM or adjustable aftermarket? Ball joints can also cause some noises, it's usually obvious (torn boot and leaking) when these fail.

Do not over-torque the top hat nut for the struts. It's not a high-torque item and you can strip the threads out if not careful. Also you should do the final torque down of the strut hat nuts (ones for chassis) and other suspension components after letting the vehicle's weight settle on the suspension. This helps ensure bushings and other components are in a neutral position. If torqued while still off the ground, you risk putting a sprung load on bushings and other components when dropped back down, which can lead to noises or premature failure of bushings.

Lastly, are you sure this noise is coming from the front? There are also known issues with the rear strut hat bushings. KYB makes a good replacement kit for the rears and it's very affordable.
Cheers!
-Icer

 

Yea ive torqued everything down with the car lifted as i have no way of having the car on the ground and getting underneath. I used OEM end links front and rear. At first i had lowered the front maybe 1/2 inch and then went a little lower although the popping noise was there even before the coilovers just seems it has worsen. Im positive its coming from the front but definitely getting new top hats for the rear as well.

 

What I've done in the past is use a jack to lift up the LCA to simulate the vehicle's weight when torqueing down the suspension components that are hard to reach (lower strut bolt, and control arms). Note: This needs to be done with care, you don't want the car lifting off your jack stands. There are exceptions, you don't need to do this for the sway bar end links or the strut hat top nuts. The sway bar end links should be connected and torqued with both front wheels (or rear) off the ground. The top hat nuts can be torqued after lowering the vehicle to the ground.

If this noise was always present, my best guess would be the front inner lower control arm bushings or the front sway bar bushings. The inner control arm bushings are pretty common. There are lots of Poly replacement options available and even complete control arm replacements that come with the bushings pressed in. The sway bar bushings are also cheap and easy to DIY. Otherwise, it could be the upper or lower ball joints and even the upper control arm bushings. Those are less common, but still possibilities worth checking. Might also be worth checking the engine mounts.
-Icer

 

i have replaced the lower control arm bushings with white line and also the sway bar bushings as well. I was also thinking about the engine mounts although i dont see any movement/vibration on the motor when the car is on. One thin i will say is that it'll do the popping noise SOMETIMES when i turn the steering wheel when im stopped but does not do it all the time. Like a said pretty much at low speeds, pulling out of the driveway or going over speed bumps.

 

I had this same issue, under these same circumstances. For me, it was the compression rod bushings. I had Whiteline bushings installed, but the 1st set of Whiteline bushings needed to be warranty replaced (I think they cracked or failed). I think my situation was a rare case, I'm also not running my Z lowered. It might be time to get a GoPro camera setup to record the front suspension. It sounds like you have already addressed all the suspect components.
-Icer

 

You did replace

because that seems like a likely issue.

 

Yes i did with the gktech bushings

 

just wanted to update this thread. I ended up finding the cause of the popping/clunk noise up in the front suspension. It was the ball joints on the compression rods that were done. The ball joints looked in good condition the boots were intact and the ball joints did not have play. I was trying to save a few bucks by just replacing the bushings with the spherical bearing but I should've just got new compression rods and put the new bearings on those. Oh well lesson learned. Suspension nice and quiet now. Car even drives smoother.

 

Glad you got it sorted! Always feels great to have the problem solved.

What spherical bearings are you referring to? Are you talking about the guts of the Ball joint? Or are you referring to another bushing?
Cheers!
-Icer

 

This one

 

so i had only replaced that on the old compression rod thinking the ball joints on it were got. So i ended up just slapping on some brand new MOOG compression rods

 

Ahhh, Ok. So you had gktech solid compression rod bushings. So the ball joints you installed are MOOG or did you replace the gktech compression rod bushings with Moog? I think you mixed the two terms up earlier. Inner bushing is compression rod, the outer (at the axle/wheel spindle) is the ball joint.
Cheers!
-Icer

 

I purchased some new MOOG compression rods and just slapped those on as is. The compression rods i had on the car (OEM ones) I had only replaced the bushings with the gktech solid bushings not knowing the ball joint on the other end of the rods were no good. I had also replaced the lower ball joints at the wheel spindle thinking that was causing the popping noise but didnt fix the problem till i replaced the compression rods with new ones. Hope that makes sense