Knocking in Rear

[Jacoburn1304]

What better mechanic than one who tries to diagnose things with no quality information to share?

About a month ago I started noticing a faint but distinguishable knocking coming from the rear of my car. It was not particular to bumps, or in a rhythm, just intermittent and on and off. Worried, I started driving less and when I did drive, it seemed to be gone. I just got back from a 10-day hiatus of not driving it, and now the knocking is completely gone. I'm sure its going to come back.

The knocking is faint, but as I said, you can definitely hear it. Seems like its coming from either the trunk or possibly the rear passenger side, but that could just be from the drivers seat. When I've had friends drive it, no knocking. There's nothing rolling around in my trunk or anything that simple. My boot lid stays shut, so its not that. Definitely thinking suspension, or bearings, or...I have no good guesses as I'm less than an average mechanic when it comes to diagnosing.

Anyone have a guess? Somewhere I should start looking for faults in order to know what to do. I am in the middle of replacing a turbo on my other car so really don't need a shop visit unless I run out of options.

So let's have some fun and make some random (but helpful) guesses!

[dtla1]

In the style of click and clack from car talk, we need some more descriptors about this noise.

High pitch or low pitch? When you do hear it, is there any rhythm or repetition? Does it sound like anything recognizable (a loud bang, or two pans clanking together, or maybe a loud version of two rubber mallets slamming together, etc).

[chris_flies]

Shock mounts aren't exactly strong points on these cars, I'd take a good look and make sure the nuts are tight.

[ShocknAwe]

Shock mounts, sunroof, rear seat latches, trunk latch, something in battery compartment, brake pads, wheel bearing, differential, axle CVs.

[Gangplank]

Exhaust might be off the connection points? Might explain the come again, go nature of it?

[Tenspeed]

This may not fit your case, but i had an issue with a noise that suddenly appeared when I hit any sharp bump.

After the dealer dropped my DCT, they didn't torque the bolt on the v-bracket that ties the bottom of the differential to either side of the chassis and it would make a noise on a sharp bump.

I tightened it and it has been quiet ever since.

[Jacoburn1304]

Well its going to have to likely go to a shop as I'm not seeing anything specific. Going to put it on its jacks this weekend and have a look around.

To describe the noise in more detail, it reminds me of hearing some construction worker hammering in the distance. Its not loud by any mean, and I definitely have a feeling now that its from the rear right. Suspension or wheel bearing if I had to just take a stab at what it might be...no clue yet though.

We'll see. Thanks for the tips and I'll try to post what I find when I find out what it is!

[dtla1]

Originally Posted by Jacoburn1304

Well its going to have to likely go to a shop as I'm not seeing anything specific. Going to put it on its jacks this weekend and have a look around.

To describe the noise in more detail, it reminds me of hearing some construction worker hammering in the distance. Its not loud by any mean, and I definitely have a feeling now that its from the rear right. Suspension or wheel bearing if I had to just take a stab at what it might be...no clue yet though.

We'll see. Thanks for the tips and I'll try to post what I find when I find out what it is!

Do you have any suspension Mods?

[Jacoburn1304]

Stock. Not sure if it was replaced before I bought it, but its up to 136k now.

[SolidWater]

OP any luck finding the sound?
Does it sound like the video I linked in this thread?
https://www.1addicts.com/forums/show....php?t=1643887

Your description is kinda similar. Reverberating plastic/rubber/metal clack on sharp bumps only in the rear (mostly driver side for me). Though it's always there, no matter temperature or how long I leave the car to sit. Nothing new done to the car aside from rear driver tire plugged and replaced...