[MatCauthon]

I've just recently got my 2016 GT. I've noticed an annoying rattle in the back when going over
some bumps. Is anyone else experiencing this and is there anything to be done for it?
Thanks

[Billfitz]

Probably a loose parcel shelf, possibly the hatch stops need adjusting.

[MatCauthon]

Originally Posted by Billfitz

Probably a loose parcel shelf, possibly the hatch stops need adjusting.

Unfortunately mine didn't come with the shelves. I'll try adjusting the stops

[Billfitz]

Odd, parcel shelves are standard equipment. Check the storage compartments under the floor, in the left rear quarter panel and the hatch, there could be something floating about there.

[KRS_SN]

if its a high pitched metallic screech/squeak its the bootid not being tight enough. DIY won't solve this(if you are a noob like me) dealer or indy adjustment required. I had mine adjusted under warranty initially dealer said such adjustments are not covered but some muscle pressure and they kindly gave in.

[meltbox]

AHA YES. Dear god this drove me insane over about half a year. Finally fixed it. First I removed the bump stops and installed rubber washers between then and the body (Otherwise you end up tearing your paint up over time as you adjust). Just grab some from home depot. You may also want to apply thread lock to it to prevent them from backing out if you do this.

YOU CANNOT FIX THIS BY ONLY ADJUSTING THE BUMP STOPS IT WILL COME BACK EVERY SINGLE TIME. This is what drove me crazy.

1. First you are going to want to take the two little plastic covers off on each side of the latch in the trunk. This will give you access to two bolts which when loosened allow you to adjust the the left/right positioning of the latch (and maybe up down slightly?). Loosen these, close the trunk, re-tighten.

2. Now adjust bump stops down/up so that when trunk is closed you can pull a sheet of paper out from between the top and trunk. Should feel some resistance but be able to pull out the paper.

3. Sometimes you have to give it a tiny bit more pressure (move bump stops up 1/8 turn or 1/4) after if you still hear knocking. Usually you're done.

Finally fixed it for me. Been gone for about a year.

EDIT: Bump stop should be technically set so that panels all line up so you may have to adjust the bump stops lower/higher first in order for step 1 to bring the panels in line with each other. Depends on how much you care about everything being perfectly aligned. I could barely tell any difference even with large adjustments. Also most important thing is left/right bump stop exert similar pressure on the trunk. You will know when this is the case when increasing the height of a bump stop makes it harder to pull paper out on the side you increased it on and easier to pull out paper on the opposite side.

[rscottf]

I've been dealing with this forever. Do you mind posting of photo of where these are?

[KCee]

No rattle for me, but I get a fair amount of "creaking" from the back end of my 2016 when slowly pulling in or out of a parking spot. I need an oil change soon so I'll probably have the dealer check. I don't hear it otherwise, usually just when I first start the car and back out of the garage. Sounds like bushings need grease or something.

[KRS_SN]

This is sometimes the only hope I mean try it. Substitute Does it move with does it rattle.

[MatCauthon]

Originally Posted by meltbox

AHA YES. Dear god this drove me insane over about half a year. Finally fixed it. First I removed the bump stops and installed rubber washers between then and the body (Otherwise you end up tearing your paint up over time as you adjust). Just grab some from home depot. You may also want to apply thread lock to it to prevent them from backing out if you do this.

YOU CANNOT FIX THIS BY ONLY ADJUSTING THE BUMP STOPS IT WILL COME BACK EVERY SINGLE TIME. This is what drove me crazy.

Thanks for the info. This sounds like what i need to do.

[meltbox]

Originally Posted by rscottf

I've been dealing with this forever. Do you mind posting of photo of where these are?

rscottf
What would you like a photo of?

Also if anyone solves creaking please let me know. I have it under hard cornering and its not terrible but I would like to get rid of it if possible. I suspect it is just plastic panels deforming in the rear as it twists slightly.

[jwiez]

Originally Posted by meltbox

rscottf
What would you like a photo of?

Also if anyone solves creaking please let me know. I have it under hard cornering and its not terrible but I would like to get rid of it if possible. I suspect it is just plastic panels deforming in the rear as it twists slightly.

I had creaking issues, and the dealer corrected under CPO service. It was related to the sunroof.

The cause was '5413507, adjusting rear cover of slide/tit'

It drive me crazy

[meltbox]

Originally Posted by jwiez

I had creaking issues, and the dealer corrected under CPO service. It was related to the sunroof.

The cause was '5413507, adjusting rear cover of slide/tit'

It drive me crazy

Oh yea the black plastic bar. I have had the sunroof seal but not that yet. I'm getting some creaking way in the back right now. May just be because I took almost every trim panel off at some point. My own fault heh. I've been trying to stuff thinsulate under everything to make it quieter. It may have had some unintended consequences in some places I fear.

[Billfitz]

Thinsulate? Trying to make the car warmer? If you're going to do anything add vinyl mastic to the inside of the trim panels. I use this:
https://www.amazon.com/dp/B01KZ5X7KO..._t3_B01BKKZ1AM

I lined my hatch trim with it when I pulled it to tint the rear window.

[meltbox]

Originally Posted by Billfitz

Thinsulate? Trying to make the car warmer? If you're going to do anything add vinyl mastic to the inside of the trim panels. I use this:
https://www.amazon.com/dp/B01KZ5X7KO..._t3_B01BKKZ1AM

I lined my hatch trim with it when I pulled it to tint the rear window.

Mastic will help with panel resonance but I found that all but the quarter panels and doors are already pretty damn well damped. I did some of the roof, rear quarters and I plan to do the doors and front quarters. Thinsulate SM600L is automotive insulation but really only good at blocking noise 1000hz+ or so. The rear wheel wells don't have much room for sound blocking material so that will be a challenge but the fronts have plenty for thinsulate+mlv.

I'll see... for now I have to finish getting all my pillar trim back on and my new front+rear dashcam installed lol.
EDIT:
https://www.amazon.com/Thinsulate-Ac...omotive&sr=1-2

EDIT2: Thinsulate in my headliner. FYI SM600L is too thick to fit up there. I had to trim it to make it fit haha.

[Billfitz]

I'm hip to what Thinsulate does. I use similar materials for everything from damping the inside of loudspeaker enclosures to curing sound intelligibility issues in churches, which have, if you'll excuse the pun, God awful acoustics.
Between the carpet and upholstery high frequency reflections don't exist in cars, other than off the glass, and high frequencies can't pass through panels either. I haven't bothered to look at my rear wheel wells, but if I ever have a reason to pull the inside panels back there I'm sure I'll line either the panels or the sheet metal under them with mastic. I've got a pile of it, so whenever something new gets pulled it gets lined.