[Garagetinker]

Has anyone noticed any suspension noise in their back end? When I go over bumps slow (1-10 mph) I hear a little thump in the rear. In checking it out i noticed if i wiggle in the driver's seat I hear the same thumping or clunking in the back (car off).

 

[campb292]

I have this noise. I don't think it is suspension related. If I bounce the trunk a bit I don't hear anything. If I wiggle in the driver's seat I hear that thumpy knock from the back. Would be nice if others could "wiggle" in their driver's seat (or back seat) with car off in a closed garage and report if the noise is heard. It may be normal but i have never heard anything like it in a car, especially a new one. Seems like something loose and thumps against the frame or base.

 

[miweber929]

I seem to have a thump or clunk at times from the headrests, especially the passenger one. May want to check there.

 

[campb292]

I seem to have a thump or clunk at times from the headrests, especially the passenger one. May want to check there.

Thanks for the suggestion! Any are appreciated. Unfortunately, this had no correlation with the noise in mine. My noise is lower in the rear and manipulating headrests had no effect.

 

[Slickweaz]

Don't know if it's the suspension, but there is a definite thump when I shift from reverse to drive right when I start to move forward. And I did come to a complete stop fyi. Also when I brake on the heavier side.

 

[campb292]

Don't know if it's the suspension, but there is a definite thump when I shift from reverse to drive right when I start to move forward. And I did come to a complete stop fyi. Also when I brake on the heavier side.

Shifting between R and D or accelerating right after R then into D does not induce on mine. Mine is only induced by getting in and out of the car, wiggling in the seats, or going over bumps and cracks at low speed.

 

[Garagetinker]

My little thump has also grown into a creak at low speeds. If I roll slowly even on smooth new road I hear a creaking noise from the rear.

 

[9thGenPrincess]

Don't know if it's the suspension, but there is a definite thump when I shift from reverse to drive right when I start to move forward. And I did come to a complete stop fyi. Also when I brake on the heavier side.

So did you get this resolved? I have the exact same issue. Car seems to make a popping noise in the rear end when the weight settles in the rear. Noticeable right before coming to a full stop and when taking off from a full stop. I can also hear it as I exit the vehicle sometimes.
Definitely coming from the rear of the cab. Not as noticeable over bumps unless I'm going slower than 3-4mph.

Anyone had any luck?

 

[campb292]

Can't speak for the user you quoted. The noise remains in my LT... Still only makes it moving in and out of the car, wiggling in and seat, or going slow over slight bumps. I have mentioned it twice to the dealer and they claim it is normal. The last time I was in they had me drive a Premier demo. It had like 300 miles and made the exact same noise. Since then I have been in a LS that didn't make the noise at all. I have learned to live with it, don't really notice it much anymore.

I still don't think it is suspension related. Most recently I have been wondering if a rear door knocks a bit? I also think the secondary battery is in the trunk... Maybe it wiggles in a harness or something?

 

[Dave AC]

Thanks for the suggestion! Any are appreciated. Unfortunately, this had no correlation with the noise in mine. My noise is lower in the rear and manipulating headrests had no effect.

Might be a bushing making the noise,

 

[The RealSlickWilly]

I just started noticing this noise in my 16 LS, I'm going to go with its a normal noise after reading this thread. Most notable taking off from a dead stop, have noticed it getting out of the car as well, was worried something might break but it sounds like a normal noise for this car.

 

[DrivenDaily]

In at least one other thread, there's a post that suggests a huge improvement by placing some kind of isolator between the spring and spring hat, or somewhere like that where there are two pieces of metal touching each other.

 

[campb292]

The noise mine made was fixed a long time ago. It was fixed at the same time they replaced the fuel tank. It has been totally quiet and normal when I wiggle in the seat or roll over little bumps. There is also a bulletin should your noise resemble 2x4s slappin'.

#18-NA-136 - Loose Lumber Type Noise Heard From the Rear of the Vehicle Over Bump (May 31 2018)

 

[The RealSlickWilly]

Yea, I was thinking it might be somehow coming from the gas tank as well from the hollow kind of noise I get, Not the end of the world as long as its not something major going wrong.

 

[Static1120]

I may be ahead of many of you all in miles, I'm at the 73,000 mile mark and mine also started as a thump, it gets worse to the point it sounds like a pop sort of like a bushing popping or the frame popping in the trunk area, especially around the 1-10mph speeds, can be recreated the most while backing up and turning in either direction, it sounds like when the tires are getting filled with air and make that popping sound when they are adjusting to the rim... I can notice it also when getting out of the car it makes the popping sound, we got it up on a lift and everything suspension wise underneath seems fine, you can park the car and push the body around from the back end and push down and sometimes if your lucky it will make the popping sound, so I believe it has to do something with the suspension or frame since the sound can also be recreated with the car off in park and not moving at all, the sound has gotten very very loud now

 

[9thGenPrincess]

I may be ahead of many of you all in miles, I'm at the 73,000 mile mark and mine also started as a thump, it gets worse to the point it sounds like a pop sort of like a bushing popping or the frame popping in the trunk area, especially around the 1-10mph speeds, can be recreated the most while backing up and turning in either direction, it sounds like when the tires are getting filled with air and make that popping sound when they are adjusting to the rim... I can notice it also when getting out of the car it makes the popping sound, we got it up on a lift and everything suspension wise underneath seems fine, you can park the car and push the body around from the back end and push down and sometimes if your lucky it will make the popping sound, so I believe it has to do something with the suspension or frame since the sound can also be recreated with the car off in park and not moving at all, the sound has gotten very very loud now

For me it’s never gotten resolved either, even after making a case with GM regarding this pop/thump noise in my 2016 Malibu. Definitely getting worse every 10k mi. The pop sound has been present since 1700mi. Now I’m at 52k and it’s just obnoxious. Of course the dealer says they can’t replicate the noise in shop. But at rolling speeds, especially when the weight of he vehicle shifts to prepare for a stop or for acceleration, I get one or two pops that are really metallic coming from the rear. It used to only be something I could hear, now I can hear it and feel it. Something is wearing. I wish the stealership would just take my money and fix the issue instead of dancing around it.

 

[tnmats]

The noise mine made was fixed a long time ago. It was fixed at the same time they replaced the fuel tank. It has been totally quiet and normal when I wiggle in the seat or roll over little bumps. There is also a bulletin should your noise resemble 2x4s slappin'.

#18-NA-136 - Loose Lumber Type Noise Heard From the Rear of the Vehicle Over Bump (May 31 2018)

So what exactly did they repair? I found a listing for the bulletin you mention but it required a subscription to view it.

I couldn't find it on the revbase web site (I find that sight fantastic but it is hit or miss on finding bulletins), any idea what their fix is? The only one that showed up was 18-NA-181 om revbase, it's about rattles overhead and in the sunroof.

http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=205369

 

[campb292]

@tnmats In mine it wasn't that bulletin - I just added that as it was new. Mine was fixed one of the times they replaced my fuel tank trying to figure out the inconsistent fill. No idea what they fixed. It was there, then it was gone. It was probably a loose shield they took off to drop the tank. Or a tank strap. Or the filler tube.

A frequent cause/fix for a rear thumping/knocking/popping noise is outlined in bulletin #18-NA-136. It adds a thick washer between the shock and the shock mount rubber to each side. If it fixes it you are done. If not, they move to replacing the knuckle. Under warranty, great, but if out of warranty, decent size job and moderately expensive. It focuses the area of housing contact so the washer makes contact with the mount not the housing of the shock. The "loose lumber" must be the housing of the shock thunking. I have heard this sound in many Malibus, mine even sounded similar.

 

[tnmats]

@tnmats In mine it wasn't that bulletin - I just added that as it was new. Mine was fixed one of the times they replaced my fuel tank trying to figure out the inconsistent fill. No idea what they fixed. It was there, then it was gone. It was probably a loose shield they took off to drop the tank. Or a tank strap. Or the filler tube.

That #18-NA-136 bulletin adds a thick washer between the shock and the shock mount rubber to each side. It focuses the area of housing contact so the washer makes contact with the mount not the housing of the shock. The "loose lumber" must be the housing of the shock thunking. I have heard this sound in many Malibus, mine even sounded similar.

Haven't heard it in my car, at least not yet. What would trigger the sound, something like going over speed bumps?

 

[campb292]

Haven't heard it in my car, at least not yet. What would trigger the sound, something like going over speed bumps?

According to the bulletin it is just an intermittent noise that sounds like hollow lumber when travelling slowly over sharp bumps. Something that would cause a quick jolt rather than a smooth rolling bounce. Mine was obviously something loose but for those that may have some noise perhaps that bulletin can help?