What is this intermittent booming noise coming from the back?

[Buz]

It occurs at lower speeds. (below 40mph)
It's a very noticeable intermittent 'booming' sound coming from what sounds like behind/under the rear seat and seems to be related to the rear suspension movement.

I have a 2020 Limited and have ruled out the following:
-ANC
-MDS
-Air suspension setting

Anyone else notice this booming?
Also, if you have noticed it, do you have the air suspension?

 

[RockYacht2020]

 

[Buz]

Not the answer I was hoping for, but thanks.

 

[RamCares]

It occurs at lower speeds. (below 40mph)
It's a very noticeable intermittent 'booming' sound coming from what sounds like behind/under the rear seat and seems to be related to the rear suspension movement.

I have a 2020 Limited and have ruled out the following:
-ANC
-MDS
-Air suspension setting

Anyone else notice this booming?
Also, if you have noticed it, do you have the air suspension?

We certainly understand why this would be concerning, @Buz. If you are not able to determine a solution based on suggestions from fellow forum members and you decide to address this with your Ram dealer, please be sure to follow up with us via private message. We would be more than willing to escalate your situation to a specialist who can work alongside you and your dealer while your truck is in service.

Kathryn
RamCares

 

[Neurobit]

It occurs at lower speeds. (below 40mph)
It's a very noticeable intermittent 'booming' sound coming from what sounds like behind/under the rear seat and seems to be related to the rear suspension movement.

I have a 2020 Limited and have ruled out the following:
-ANC
-MDS
-Air suspension setting

Anyone else notice this booming?
Also, if you have noticed it, do you have the air suspension?

You positive is not the ANC? Only thing I can think of.

 

[Aseras]

The only time I hear anything is if some mud comes off and hits under the back.

 

[Buz]

I unplugged ANC to test and the noise is still there.
Best I can describe it is when the rear suspension rolls over minor irregularities in the road there’s an accompanying drumming sound in the rear of the cabin. It doesn’t always do it and it’s usually at lower speeds under 40 mph.
i’ve never had a vehicle that’s done this.

 

[ldoh]

I would guess something is loose. Since it happens frequently and for known conditions, I'd see if I could mount a camera underneath to catch it.

 

[ccokeman]

The drone from eco mode at low speed can be pretty loud and booming. Especially if you are a rear seat passenger.

 

[Scram1500]

I unplugged ANC to test and the noise is still there.
Best I can describe it is when the rear suspension rolls over minor irregularities in the road there’s an accompanying drumming sound in the rear of the cabin. It doesn’t always do it and it’s usually at lower speeds under 40 mph.
i’ve never had a vehicle that’s done this.

I have been chasing the boom myself, almost sounds like a drum. It's one of two things in my opinion, or both are connected. I think it's related to the rear cab vents and the hilariously thin sheet metal on the front of the bed. The vents seem to pop or flap open, only noticeable a slower speeds (change in air pressure as opposed to highway speed?), and possibly causes a reverberation in the thin sheet metal. I don't hear it with the windows up and the fan on with outside air. I believe that forces the vents open and they can't flap open and closed.

 

[JGRaider]

I have the same issue occasionally, and it drives me nuts. Sounds like something is loose in the bed, but nothing is in the bed. Could it be something loose underneath the bed?

 

[Scram1500]

I checked all the bed bolts and they are tight. I also checked the body bolts, they were tight as well. However, body mounts/bushings can go bad and will make noise no matter how tight they are but that would be a popping noise as opposed to a boom.

I spent a lot of time under there and hit everything with a rubber mallet, there isn't much underneath the back to cause any noise. I also drove around without the spare or the tailgate with no luck. The closest I found to the noise was smacking the gas tank, but the straps and everything were snug. Maybe the simple answer is there needs to be more sound deadening added to the bed.

Another thought, rear fender liners?

 

[Buz]

I checked all the bed bolts and they are tight. I also checked the body bolts, they were tight as well. However, body mounts/bushings can go bad and will make noise no matter how tight they are but that would be a popping noise as opposed to a boom.

I spent a lot of time under there and hit everything with a rubber mallet, there isn't much underneath the back to cause any noise. I also drove around without the spare or the tailgate with no luck. The closest I found to the noise was smacking the gas tank, but the straps and everything were snug. Maybe the simple answer is there needs to be more sound deadening added to the bed.

Another thought, rear fender liners?

Thank you for posting. As the OP I was starting to think I had the only truck that did this.
This is the only issue I'm having that makes me think I won't keep the truck as long as I usually do.
Do you have air suspension? I'm trying to rule that out. I do have it.
I think you may be on to something with the vents. How to test though?
Oh, and i have the rear fender liners too, so yes it could be those.

 

[Scram1500]

I'm on coils. I might have become used to the noise as I don't think I hear it anymore or it's been reduced somehow, old age maybe. Could be a coincidence, but the last thing I did was put Bilstein 4600 shocks in the rear and after that it seemed more quiet

A quick check of the vents with the truck off is look between the bed and the cab while moderately slamming the passenger rear door closed. You may need a flash light to see but you'll hear them flap open and closed. If you crank the fan with recirc off and look they are wide open. To fully test the cab vents will require removing the back seat and body panel behind the seat. Then drive around hitting bumps with a window open, then closed with recirc on and recirc off. The intermittent nature of the noise makes it difficult to nail down

 

[Buz]

I checked all the bed bolts and they are tight. I also checked the body bolts, they were tight as well. However, body mounts/bushings can go bad and will make noise no matter how tight they are but that would be a popping noise as opposed to a boom.

I spent a lot of time under there and hit everything with a rubber mallet, there isn't much underneath the back to cause any noise. I also drove around without the spare or the tailgate with no luck. The closest I found to the noise was smacking the gas tank, but the straps and everything were snug. Maybe the simple answer is there needs to be more sound deadening added to the bed.

Another thought, rear fender liners?

I removed my rear wheel well liners yesterday and the booming noise is still loud and clear. So to save everyone some time It is NOT the rear wheel well liners.
Has anyone else been able to determine the source? Could it be the sub attached to the back wall? I unplugged my sub last month and I still hear the booming noise. Perhaps it's the sub in its passive state connected to the thin back wall?

 

[du4life25]

I thought I was going nuts but I guess I'm not the only one. I've had my truck for three weeks now and I noticed the noise immediately. I figured it had something to do with my lift but evidently not if other people are having the same issue. Like someone else mentioned, I only notice it when I'm driving at slower speeds and hitting irregularities in the road. Someone had mentioned that it may be because of a stiffer suspension and it needs to be worked in a little bit? Not sure I believe that though. My truck will be going to the shop shortly to see if they can figure out what the issue is.

 

[Buz]

I thought I was going nuts but I guess I'm not the only one. I've had my truck for three weeks now and I noticed the noise immediately. I figured it had something to do with my lift but evidently not if other people are having the same issue. Like someone else mentioned, I only notice it when I'm driving at slower speeds and hitting irregularities in the road. Someone had mentioned that it may be because of a stiffer suspension and it needs to be worked in a little bit? Not sure I believe that though. My truck will be going to the shop shortly to see if they can figure out what the issue is.

Do you have the HK sound system, or more importantly, do you have a subwoofer mounted to the back cab wall?
I'd like to eliminate the subwoofer (in it's passive, off state) as a culprit.

 

[Aseras]

Did you check the spare?

I've seen some lifts done ( by dealers ) where the links are not done right and shear off as they are not long enough. They look like they are in place but bang around and when you put the truck up on the lift you see it hanging. Bolt sheared off.

 

[Buz]

Did you check the spare?

I've seen some lifts done ( by dealers ) where the links are not done right and shear off as they are not long enough. They look like they are in place but bang around and when you put the truck up on the lift you see it hanging. Bolt sheared off.

Bone stock Limited. No lift.
I'll check to make sure the spare is cinched down hard enough. Honestly don't think it's the spare though but I'll check.

 

[du4life25]

Do you have the HK sound system, or more importantly, do you have a subwoofer mounted to the back cab wall?
I'd like to eliminate the subwoofer (in it's passive, off state) as a culprit.

I do have the HK system but to me it almost sounds like the noise comes from different corners of the truck at different times which would tell me it has something to do with the suspension.