View Full Version : Found the source of underdash rattle/vibration! Dont try this at home.

04-25-12, 08:02 PM
I wouldnt recommend my technique for finding this rattle source. I had been been bothered for weeks with an intermittent vibration/rattle seemingly under the left dash which occurred only at smooth highway speed. One day while driving on the interstate, I decided to see if perhaps the parking brake was rattling. Maybe if I gently applied the brake to the first notch it would stop. Drat. Didnt effect it. So I reached down to release the parking brake, and accidently pulled the hood release! Crap! Well at least the safety worked. While finding a safe place to pull over, I noticed the rattle was gone!!! WTF? Turns out the drivers side hood hinge was loose at the joint. After I stopped, I grabbed the hood while open and moved it laterally back and forth and reproduced the noise. The dealer was sceptical but finally agreed with the diagnosis and replaced the hinge under warranty. No more rattle! Anyone else had this problem??

04-25-12, 08:59 PM
I have not had the rattle, but I have pulled the hood release while underway and trying to confirm that I had remembered to release the parking brake.

04-25-12, 09:34 PM
I had that same rattle when I first got my car, it was my first warranty item. I think they replaced both the hinges for me but I don't recall exactly. I remember it being quite annoying and it only seemed to come up at highway speeds

04-26-12, 02:00 AM
nope, have not had the issue of accidently pulling my hood release while driving:thumbsup:

04-26-12, 09:08 AM
I have a rattle under my dash but I'm pretty sure it's caused by my big cammed engine and CS motor mounts. I can push on the dash (or torque the steering wheel to the side) and the vibration/rattle will go away. Mine doesn't rattle at highway speeds though - just when idling at a stop light.

Cadillac Cust Svc
04-26-12, 11:39 AM
Glad you're alright, aantalis! Thank you for sharing, and I hope you're enjoying your rattle-less V.


Cadillac Customer Service

04-26-12, 06:33 PM
yes my hood hinges have the same rattle

04-26-12, 10:12 PM
Same here.

04-27-12, 03:26 AM
i have a non sequential rattle/clicking coming from the left side of the dash as well. sounds like it is inside the dash, to the left of the steering column and i will confirm that the clicking sounds get more pronounced at highway speeds. it is very very annoying and would be costly to diag considering no more warranty. if anyone could help diag this or any suggestions/comments would be a great help. have video taken from iphone 4. will be up shortly.



04-27-12, 06:05 AM
It's the hood hinge. This is a design defect on all 1st generation CTS and CTS-Vs. In order to fix it, you either need to get it replaced by a GM dealership (which they typically refuse to do) or go to Home Depot and pick up a couple of rubber/poly washers. You might want to do both sides while you're at it because the passenger side will eventually go too. Fortunately, the washer fix works--my hood started rattling at 7,000 miles and 20,000 miles after the mod, it's still silent.

Sorry that I can't be more specific regarding which nut needs a washer--I'd have to go out and look. If that's important to you, let me know. I do recall that you can manually tweak the hinge (up down left right) and reproduce the same clicking with the hood open.

04-27-12, 10:43 PM
gotta be that hinge. Open the hood and move it laterally back and forth. You should hear a creaking sound.

04-28-12, 06:47 AM
gotta be that hinge. Open the hood and move it laterally back and forth. You should hear a creaking sound.

For me, it was a clicking sound.

04-28-12, 07:09 AM
A stack of small hard foam rubber pads next to the hinge fixed mine years ago.

04-28-12, 07:41 AM
No rattle here, but I do have a whine. :devil:

11-14-13, 12:24 PM
Dealing with the hood hinge rattle here as well. Here is a short video I took of the rattle to show anyone dealing with the issue what it sounds like.


I went to Home Depot to pick up a few nylon washers to tighten the bolt. Looking at the bolt before I took it out it looked like I needed a small washer. Once I took out the bolt I saw that there is actually a wide part of the bolt that sits inside the hood hinge. Here is a pic of the bolt.


I bought a few washers from Home Depot but the largest one I bought was 3/8" ID. It was just too small to fit over the wide part. Going to try 7/16" tonight.

For those who have done this already, Is there any trick to removing the bolts without damaging the paint on the bolts? I tried to be careful but the socket took off some paint. At least it is hidden by a little rubber boot but would prefer not ruining the paint.

Also is the bolt the part that is out of spec or is it the hinge itself that is bad. In other words can I simply order a new bolt?

02-24-14, 12:15 PM
Finally got around to adding a nylon washer to the hood hinge bolt. Wish I would have done it months ago. Took 5 minutes and what a difference to drive without the annoying rattle.

I figured I would take a pic of the washer that I used to save you some time looking for it. I picked it up at Home Depot.

The inner diameter of the washer is just a bit too small so I opened it up a little with a 3/8" drill bit and then it slipped on nicely.

The damaged paint on the bolts are from the first time a open the bolt (10mm). This time around I wrapped it with some Teflon tape to protect it.

Luckily it is behind a little rubber boot so no big deal but what do you guys usually do when opening a painted bolt?

02-24-14, 07:38 PM
Thanks for the pic.

11-11-14, 11:42 PM
After reading about the hinges, i was able to duplicate my rattle and so i thought that was likely the cause - i didn't want to remove the bolts so i just cut the washers and loosened the bolts and pushed them in and tightened them down - but the rattle was still there - i removed the hood prop piston cuz it made that sound too, but no luck - after 2 days i did find my rattle though and it was the wheel well liner on the driver side front. i put in new push-anchors or whatever they are called and shimmed the plastic as well - it seemed to be banging against the metal under it - you could duplicate the noise before hand by just jiggling the liner - you can grab it just behind the wheel well at the low point near the ground, but it might make the actual noise higher up. I was greatly relieved to be rid of that irritating noise - i don't even want to listen to the radio now - i'd rather just revel in that hard-earned silence.