Horrible creaking sound
Thread Starter
Pro
Joined: Apr 2016
Posts: 512
Likes: 62
Horrible creaking sound
I just got my first C4 the other day, an '85. I got a real good deal on it which is why I bought it. It had some minor mechanical issues which I fixed, it runs and drives good now. However, it has a horrible creaking sound when I hit bumps, its right behind my head on both the driver and passenger sides. Thinking it might be from the targa top or maybe from the plastic trim that goes up and over my head I removed the top and the trim but the creaking is still there. I even sprayed some silicone on the seal for the rear hatch glass and even tried driving it with the rear hatch open to see if the noise was coming from there to no avail. I can't pinpoint exactly where the creaking noise is coming from but it's right behind my head and behind the passengers head in the pillar that goes up and over the car. I'm sure this isn't the only C4 with that issue, does anybody know what's causing it and how to fix it? Any help is greatly appreciated.
Thread Starter
Pro
Joined: Apr 2016
Posts: 512
Likes: 62
No, when she's in the car there's a horrible squeaking sound on the right side of my head, not a horrible creaking sound coming from behind my head...
But seriously, I really need some help on this, I need to know what's causing the creaking sound and how to fix it.
But seriously, I really need some help on this, I need to know what's causing the creaking sound and how to fix it.
Thread Starter
Pro
Joined: Apr 2016
Posts: 512
Likes: 62
Update:
I just found the source of the creaking sound, it's from my rear control arm bushings! I've only had the car a few days and have only jacked up the front of the car to work underneath it. I decided to jack up the rear of the car a little bit ago today after I made this thread and as it was going up the rear control arm bushings started to make that horrible creaking sound. I sprayed them with some silicone spray and they stopped creaking and when I took it for a test drive lo and behold, the horrible creaking sound is gone thank God. The noise must have been being transmitted up through the frame and sounding like it was coming from right behind my head. If your C4 is making a horrible creaking sound in the interior that sounds like it's coming from right behind your head check your rear control arm bushings, chances are the noise is coming from there.
I just found the source of the creaking sound, it's from my rear control arm bushings! I've only had the car a few days and have only jacked up the front of the car to work underneath it. I decided to jack up the rear of the car a little bit ago today after I made this thread and as it was going up the rear control arm bushings started to make that horrible creaking sound. I sprayed them with some silicone spray and they stopped creaking and when I took it for a test drive lo and behold, the horrible creaking sound is gone thank God. The noise must have been being transmitted up through the frame and sounding like it was coming from right behind my head. If your C4 is making a horrible creaking sound in the interior that sounds like it's coming from right behind your head check your rear control arm bushings, chances are the noise is coming from there.
Last edited by TheGreek!; Mar 19, 2018 at 12:00 AM.
Safety Car
Joined: Aug 2013
Posts: 4,430
Likes: 609
From: Minneapolis Mn
I'm assuming what you're calling control arms are the trailing arms on the rear end. Prothane and Energy both sell poly bushing replacement kits for C4's.
Additionally there are places that sell rebuilt trailing arms like this: https://corvetteparts.com/c4/catalog...rms-components
IMO if you want the ultimate upgrade check out the Banski rear suspension package. It replaces the trailing arms, camber rods & toe rods with replacements that have heim joints on them. Because of the way they can articulate, I'm fairly sure they can't bind in virtually any position. I put the Banski packages on my 86 and I'm very pleased with the results.
If you're doing something with the bushings, it would be a good time to go ahead and replace the U-Joints while you have things taken apart. Another is to check the condition of your brakes and hubs right away.
Additionally there are places that sell rebuilt trailing arms like this: https://corvetteparts.com/c4/catalog...rms-components
IMO if you want the ultimate upgrade check out the Banski rear suspension package. It replaces the trailing arms, camber rods & toe rods with replacements that have heim joints on them. Because of the way they can articulate, I'm fairly sure they can't bind in virtually any position. I put the Banski packages on my 86 and I'm very pleased with the results.
If you're doing something with the bushings, it would be a good time to go ahead and replace the U-Joints while you have things taken apart. Another is to check the condition of your brakes and hubs right away.
Le Mans Master
Joined: Feb 2005
Posts: 6,485
Likes: 566
From: Clearwater Florida
..... My guess is that the PO installed poly bushings ... Polyurethane bushings require a very liberal slathering of silicone based grease at time of assembly or they will squeak ... all of the kits contain a small tube of this grease but its hardly enough to cover all of the bits that need it ... you might need to disassemble the bushings and re-apply grease to the through bolts and the steel bolt spacer for a more permanent solution ... I have used NAPA Sil-Glide grease with success .....
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Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
..... My guess is that the PO installed poly bushings ... Polyurethane bushings require a very liberal slathering of silicone based grease at time of assembly or they will squeak ... all of the kits contain a small tube of this grease but its hardly enough to cover all of the bits that need it ... you might need to disassemble the bushings and re-apply grease to the through bolts and the steel bolt spacer for a more permanent solution ... I have used NAPA Sil-Glide grease with success .....
Also check the rear spring bushings.
Last edited by ghoastrider1; Mar 19, 2018 at 10:18 AM.
