Help me diagnose a squeak/creak coming seemingly from the rear of my car


#1

It happens most often when the going over bumps and uneven roads, I tend not to hear when going over potholes (probably because the sound of the crash over potholes tend to overpower the squeaks.) It sounds like it’s coming from the rear right-side.

So, it must be the suspension then right? You would think so, except:

  1. It sounds like it’s coming from inside the car rather than outside. Since I have the windows all rolled up, the squeaks would have to be pretty loud for me to hear it, if it’s coming from outside.

  2. Did the bounce test, pushed it with most of my weight to hear if it makes any sound. It doesn’t.

Any ideas?

Car: 2007 Corolla.


#2

Bushings. Or struts.
The most common squeakers are the bushings that hold the sway bar to the unibody. The bar twists in the bushing’s hole every time either or both wheels move up or down, which is all the time, and it wears the hole bigger. It can be diagnosed readily from under the car, but that’s the only way to find it. It might be able to be verified by liberally squirting silicone lubricant on the bushings and seeing if the squeak goes away.


#3

As usual, I agree with mountainbike. The reason it might seem louder than it should is that these tin can unibody cars transmit sounds pretty well.

Is there a spare tire well in the trunk? That is also worth a look to see if the hold down has come a little loose and letting the spare squeak around. And where ever the jack is stowed if it isn’t in the same compartment with the spare.


#4

I does sound like a rear suspension problem. But it might be worth it to remove everything from the back seat and trunk including the spare tire and jack, and see if it goes away first.


#5

Take it to a shop and ask how much they would charge to spray down the rear axle beam bushings with a silicone lubricant.

Tester


#6

Thanks for the suggestions. The first thing I did was to try to shake interior pieces, the seats, the… glove box… and, well there really isn’t that much that moves.

I’m going to do the easiest thing first and see if it could be the spare tire, or spare tire jack moving about.

Then, I’ll proceed to locating suspension bushings in the rear and front and then spray it to see if it does anything.


#7

You may even be able to shake the sway bar and find it loose within its hole. You cannot damage suspension components by shaking them by hand. Just be sure the car is securely elevated. We don’t want to lose any new friends.


#8

I will say that it is often difficult to replicate noises you get while driving by trying it my hand. I have one confirming story - I recently had a broken rear sway bar link that creaked sometimes while driving, but never while I bounced the car or pulled on anything. (It was the remainder of the link - the bushing that was left rusted onto the bolt). And I have one reverse story - the front sway bar bushings in my car will squeak by hand but not while driving.

In any case, I’m not telling you not to shake things about. Sometimes that works. But if you do start investigating things one by one eventually you will find it. Note that springs will creak when broken, but it can be hard to see the breaks. This car is probably too new for a broken spring, but you never know, especially if you’re in a wintry climate.


#9

Just to add on to what has been stated, what about shaking the exhaust pipe to see if the squeak appears? Maybe an exhaust hanger is acting up.


#10

Thanks for all the suggestions. I’m going to try all of them, then return to update this thread.


#11

Okay, Update:

With my order of Permatex silicone spray on the way and after ascertaining that WD-40 is safe on rubber, I sprayed some of that WD-40 all over the bushing that allows the rear torsion beam axle to pivot up and down. Then I drove immediately around town making sure to crash into small potholes and bumps. The creaks were still there.

However,

A few days after, I haven’t noticed the creaks at all. So, maybe the WD-40 took a few days to soak in and did its job (at least temporarily.)

Or, maybe the weather got warmer…

At the very least, I’m encouraged that I may have found the problem spot. Once my silicone spray comes in, I’m going to jack the car up and try to apply the lubricant properly.