thanks, i will try that out tomorrow morning. i'm kind of intimidated by the adjustment of the preload since i only have a small jack and jackstands. it will probably take me 4 times as long to do one adjustment then it would at a shop with a lift. the place i bought the coilovers from is going to help me try and fix it, i'm gonna swing by there tomorrow

No prob. Hopefully it's something simple like that. Let me know if that fixes it. The molded foam back there is pretty hard so it sounds like knocking when the road us rough.

unfortunately it snowed like, a lot last night, meaning i can't go and fix it and test it b/c i my winter tires don't come until tomorrow.:mad:

hey jeff i actually had bc coilover on my altima coupe and i got the same sound your describing. everytime it rained or snowed i would get the sound. i went to a shop and they put wd-40. they turned the wheel so they could spary inside i guess the coilovers itself? not really sure where they sprayed. i know some people might tell you its a bad idea but it got rid of the sound for me. and i had no problems after that. (if anyone goes this route just make sure it doesnt get anywhere by the brakes i just remember the guy telling me that if i do it on my own.)

ok so i just went out and confirmed that it is not any of my interior styrofoam bits. i took out a bunch of the stuff, and then stood in the trunk and kind of bounced a bit and was able to get the sound to happen. its def only from the right shock. the installer says that the preload is already maxed out, so its definietly not b/c it is not enough preload. they also confirmed that that rubber isolator thing that goes under the spring is most certainly there. also they said they never touched my sways and that those wouldn't have just randomly come loose. UGH
BC said that if it was a bad shock, it would sound like a loud hammering sound, and that if i want to rule out everything else i should switch the shocks from one side to the other to see if the sound moves from the right rear, to the left rear.

You may want to check that the spring mount is flush with the frame of the z. I know some people had issues with this. You can only tell if you take the springmount off and see if the Metal tabs are not bent.

i'm not sure how to do that....

:mad:
i'm really getting annoyed with this! i literally can't stand driving my car right now. i start driving and immediately become totally aggravated.

too lazy to read the entire thread but have you determined which corner the noise is coming from?

do you have any knowledge or have worked on a car? if so, start removing bits to find the root cause. here's where i would start on rattles.

listen for which part of the car the noise is coming from. Is it the front or rear?

unlink one of the endlink (dont need to remove) front or rear and see if that eliminates the noise.

if not, link the endlink, remove the strut or shock and replace using stock bits. dont worry about the alignment for now.

if you determine it's the shock or strut, use the stock mounts on the aftermarket strut/shock and see if the noise comes back.

if it doesn't then it's your mounts.

if it does, then it's your stock/strut. get it replaced.

finished.

its most certainly the right rear.i guess i will try that trial and error approach. Unfortunately, thats going to take me such a long time to do in my garage. i have some knowledge and have worked onmy car before, and i mostly learn by doing and reading , and i've never DONE suspension so i guess it will be a learning experience.

my mental issue right now is, if it was something install related, i can see no reason why the install shop would spend an hour checking everything and NOT fix it. furthermore, if it were install related, it would have presented itself immediately, or very soon after, not after 2 weeks.

I couldn't hear any noise in the sound clip. Is it a clunk sound or a rattle?

its more of a rattle at this poinnt. turn your speakers up a bit and you will hear it. its throughout the whole thing. it might be hard to hear because it barely stops. its like bummmm bad dum bumm. i have sound clips that are better as well, but not on youtube.

If it's a constant rattle then I don't think it's The spring mount. You should have someone bounce inside your hatch and look underneath your z.

i wouldn't count on it just being an installation issue. it can well be a manufacturing defect. if it's not the endlinks i would check the rear spring orientation (some springs rub against the carrier unless positioned a certain way), pillow mounts could make noise too if worn, but it's too new so i would consider it a defect if it turns out the noise goes away when you use stock mounts.

i have bounced in the hatch, and the noise happens. i'm gonna take the wheel off and see if i can't find any issues right now.

id be funny if it was something loose (like a wheel lock key or wrench) rolling around in the spare area or under the trunk liner... (hint hint) :D