J30 Rattle?!

[carlos_knology]

Hey guys, Carlos here. '95 J30 w/75K miles.

Lately when I ride over a bumpy surface, I hear what sounds like a metallic rattle coming from the rear of the car.

It sounds as if the sound is coming from the rear speaker shelf but everything I've checked in that area seems fine.

I've checked the trunk (it's empty). Checked the car jack to make sure that's not it. It's tight in there.

I'm wondering if it could be something in the space between the back seat and the trunk (gas tank area).

Carlos

[robmcole]

You might want to check the nuts at the top of the suspension tower. My friends 92 Camry had this problem and the nut was loose. Made a metal to metal sound over bumps. It had about 1/8 inch play in it.

-Rob 93 J30

[Q451990]

I echo what Rob said. A loose center nut can also cause this sound - I describe it as a receiver trailer hitch sound. Very worn bump stops, bushings, and rear shocks can also create some play there and create this noise.

Heath

[J-Owner]

Hey Carlos,

Another thing you might check is that back seat belt anchor up by the headliner on the drivers side. I had the same kind of noise coming from what sounded like the speaker shelf but it turned out to be the metal seat belt anchor inside that panel rattling against the car frame.

This may or may not be it but that is what mine was. Hope that helps.

[carlos_knology]

Thanks for all the replies guys. I'll have to check out all your suggestions. I'll let you know how it goes.

Carlos

[carlos_knology]

Well, I couldn't stand it and had to go in the garage to mess with the car and check out your suggestions.

I checked the suspension tower nuts and they are TIGHT... could not get them to tighten any more.

Checked both seat belt anchors in the back seat and although both of them do rattle when i tap them with my finger, the nut that's there cannot be tightened any more. It looks like the anchor is meant to be somewhat loose by design but I'm now wondering if that's what's causing my noise.

Ended up pulling the trunk trim and checking EVERYTHING back there but nothing seems loose. Will keep looking...

Carlos

[j30t]

turn the music up!

[J-Owner]

Hey Carlos,

Try shoving something between that seat belt anchor and see if that fixes it. I had to fold up a piece of cardboard and stick between the anchor and the car. I know that is ghetto but hey it worked. I agree that the nut cannot be tightened anymore so that is why you have to stick something between it.

That solved my problem. I still don't know how it started or why but it was a quick easy fix and with that panel on there no one would ever know you had to ghetto fix it. See if that works, if not then I tried.

Good luck.

[Eswift]

sometimes the heat shield on the cats gets loose, and it doesnt always sound like its coming from below you.

[carlos_knology]

This weekend while giving the J30 the Zaino treatment. I actually found the source of the rattle.

As I put my orbital buffer on the roof of the car (driver side, just behind the sunroof) I heard the evil rattle loud and clear. If I tap on the roof above on that area, I hear the metallic rattle.

I thought maybe I left something loose when I did my sunroof repair but that's not it at all. It looks like there is a metal support beam that goes from back door to back door along the roof line.

Between this beam and the roof metal are what look like round adhesive disks (about the size of a dime). I'm assuming that these disks are supposed to somehow insulate vibrations but it's not working for whatever reason.

I took off the dome light and the driver-side rear sissy-bar. This allowed me enough slack to pull that corner of the headliner down to peek in there with my flashlight. If I reach in there and stick my finger in the holes that are on the beam, I can actually move the beam up and down.

The question now is.... how do I fix it! Space is tight and the sunroof door slides past this area when opening so I can't obstruct its path.

Here are some pics..

Picture one gives you an idea of where I was looking (driver side, rear door opening.... pulling down on headliner).

Picture two was taken by sliding my dig. camera between under the headliner while I illuminated the area in question with a flashlight.

Let me hear it gurus!!

Carlos

Here's picture # 1.

[carlos_knology]

Here's picture two...

[VimyJ]

Great work tracking that rattle down. Epoxy? A shim?

[Q451990]

I'd try to get some caulking in there. Silicone RTV would probably do the trick, or even non-silicone bathroom caulk. Just let it dry good before you put the headliner back against it - you don't want to glue the headliner in!

Heath

[carlos_knology]

I'll give the caulk a shot. It's just REALLY tight in there. Took me a while to just get the picture.

The good news is that the beam does not touch anything. The sunroof mechanism sits between that beam and the headliner.

Thanks again,

Carlos

[carlos_knology]

Ok, it's fixed! Rattle is gone!

Here's what I did.

1- Took off both sissy bars by the rear seat.

2- Pulled off the trim that surrounds the rear seat belts (both sides). That trim is held in place by clips so you just pull on it. I did not remove the trim, just got it loose.

3- Removed dome light.

4- With everything out of the way, I pulled the headliner down and held it down with some bungee cords. That gave me about a foot gap to work with. It was very tight but the only other alternative was to completely remove the headliner.

5- Reached under there and slid about 4-5 wooden craft sticks (like popsicle sticks) between the roof and the loose beam. i slid them perpendicular to the beam. This greatly reduced the rattle but not all.

6- If you look at the previous picture, you'll notice the the loose beam has holes in it. Well, I took a can of Great Stuff (spray-can insulating foam - the expanding type) and sprayed it in all the holes until the stuff was visible from the adjacent hole. Did this all the way down the beam. BTW - I did not remove the wooden sticks, I left those in there.

7- I let the foam sit for about 45 minutes to let it expand. After it expanded, I cut off the excess that expanded out of the beam holes since the sunroof slides back into this area.

8- Put everything back together.

Now when I tap the roof over the beam, all I hear is a nice thud. :-)

Carlos