Coilover owners experiencing rear deck rattle?

[SplitsenseM35]

Since installing the BC coilovers bringing additional stiffness to the rear suspension, are any of you experiencing a loose rear deck rattling on hard imperfections in the road? It doesn’t rattle all the time only hard hits to potholes or road imperfections and seems to only affect the passenger rear. I am wondering if this is normal or if the installer broke of one of the tabs to hold the deck in place. I did have a slight rattle even before the installation with my OEM sport suspension/19in sport rims but now it’s more noticeable with the BC’S due to the harsher ride. Can I put a foam block or something between the deck and body? Would something like this work and quiet the rattle down? Just wondering if I am alone here or if this is common with coilovers. Thanks in advance.

[Ilya]

I have a rear deck rattle too but I can't verify if it's the suspension as I had a bit of it before I lowered.

I'm just going to sound deaden the trunk and that should help out.

[svard75]

I don't have a rear deck rattle but I do have a rattle coming from the speakers in the seats. I think there was a TDSB that covers the grills on those speakers??

[SplitsenseM35]

I have a rear deck rattle too but I can't verify if it's the suspension as I had a bit of it before I lowered.

I'm just going to sound deaden the trunk and that should help out.

Exactly, I can't tell if it's the suspension but I'm sure it's the rear deck. Not so much a rattle but kinda like something is loose in the deck. Like a duh duh sound when going over potholes. I did have this before lowering the car so I'm not too concerned but it gets annoying at times

[FndMspot]

I have a right rear deck rattle for years, and have had several dealers chase down the noise, including the service manager riding in the trunk. The only resolution that minimized, but not elimated the rattle was replacing both the shocks and the struts. After one year the noise is coming back?

[SplitsenseM35]

Does anyone know if bad rear sway bar links can cause this sound?

[merlinq2]

That is great question- I have asked the infiniti repair shop and no one knows the answer to that. Most of the techs would need to go to the infntiti help line/center and ask those questions to see if there is anything listed.

I would suggest that a rattle in that area could be coming for a fatigued weld. When you replace the suspension the new more supple ride (compared to the older high mileage parts that were replaced) will in general soften up the ride cutting down on the over all frequency of the bumps. Therefore no rattle until the suspension settles etc.

I think I did find another posting on the net that talked about some bad welds on the earlier M's (while looking to buy one), most of the postings listed noises, creaks, rattles etc but never did post a solution.

Might want to look at the bushings in and around the sway bar. When those fail you get squeaks and booming noises from the rear end, sounds like the car is bottoming out.

[DeanM45]

Get someone to ride in the back and put pressure on the parcel shelf cover (where the sub grill is). There are bushings to isolate it in a few places and it just "snaps" into place when assembled. If the bushings are gone or deteriorated you can have an odd rattle there.

[SplitsenseM35]

update!! - I located the rattle to my rear deck brake light area, the deck was rattling against the rear glass, so I wedged some foam between the deck and glass and now its quiet on harder bumps. I guess the M was not designed for harsher coilovers and didnt think about this area moving around.