What's the grumbling noise on deceleration?

[Prattguy1]

2019 new style 5.7L. Had it a month, and keep hearing that low-pitched grumbling noise when I decelerate. Just curious what it is - turbocharger or something? Almost seems like a jake brake.

 

[gofishn]

It's Your Hemi.
It's Grumbling because it's Mad, at you, for slowing down.
See Hemi's want to run. Preferable, Wide Open and against . . . well, any vehicle dumb enough to try and run with it.

so, let the Hemi run.
Once it has made a few Mustang owners Suicidal
Camaro owners insanely Jealous
and *** Fanboys hanging their heads in Shame and Regret,
most of the Grumbling will go away.
Not all though.

Kind of like a two year old, Hemi's never want to rest.

 

[crash68]

Do you have the e-Torque version? It could be the alternator regenerative braking that charges the battery pack. Another possibility is it could be something in the rear differential.
Keep in mind the transmission takes a while to learn your driving style. Frive the vehicle normally, don't baby it or beat on it and if the noise gets worse, bring it in.

 

[Octane]

I had a high pitched grumbling in my hemi Challenger but it turned out to be just the significant other skeered to death of my highly skilled high speed driving and stopping on a dime afterward...she made me stop tho. Lol

 

[RBinNC]

Does the Eco light come on? I've noticed this when MDS is engaging. Take it to the dealer to see. Could be something else

 

[atrupo]

Try giving the throttle a little "blip" next time you hear it. If it goes away, it is the MDS.

 

[BJSwizzle]

I bet that when I slow down and turn when I put my truck in 4wd lock, when I go to 2wd, it’s gone

 

[1morepart]

Mine makes a sound when decelerating. Not as loud as you describe. Essentially when slowing down, the transmission is down shifting(one noise) and at points may turn off 4 of your eight cylinders (another noise).

 

[RamCares]

Does the Eco light come on? I've noticed this when MDS is engaging. Take it to the dealer to see. Could be something else

Hello RBinNC,
Please keep us updated on your dealer visit. If you are in need of any additional assistance throughout this process, please do not hesitate to reach out to us privately.
Laura
RamCares

 

[Musky Mike]

https://www.ramforum.com/threads/drone-sound-coming-from-the-engine.141658/#post-2015318

https://www.ramforum.com/threads/drone.131498/


https://www.ramforum.com/threads/active-noise-cancellation-anc-bypass.148763/#post-2104598

 

[RBinNC]

Hello RBinNC,
Please keep us updated on your dealer visit. If you are in need of any additional assistance throughout this process, please do not hesitate to reach out to us privately.
Laura
RamCares

Hi Laura. The dealer replaced the active noise cancellation dampeners and it still vibrates the same. Has to be under light load, 1900 rpm in eco mode.

 

[RBinNC]

https://www.ramforum.com/threads/drone-sound-coming-from-the-engine.141658/#post-2015318

https://www.ramforum.com/threads/drone.131498/


https://www.ramforum.com/threads/active-noise-cancellation-anc-bypass.148763/#post-2104598

Thanks for those links Mike. I don't believe my issue is a drone per se. It's not related to any specific gear or speed. This is a vibration at very specifically 1900 rpm in eco mode under load. I can feel it in the gas pedal, my seat, the cab. I know it's Eco mode because the second I hit the gas or gear selector to disengage Eco mode it stops.

 

[RamCares]

Hi Laura. The dealer replaced the active noise cancellation dampeners and it still vibrates the same. Has to be under light load, 1900 rpm in eco mode.

Hello RBinNC,
We are certainly sorry to hear about your ongoing concern. If you are interested in getting connected with a Case Specialist that can work with your dealer to help find a potential solution to this, please reach out to us privately with your VIN and we can get started on that process.
Laura
RamCares

 

[TestPilot57]

When I am under engine braking I EXPECT to hear some (what some might call) grumbling. Pop that exhaust, baby! I love it! And wouldn't mind in the least if it were as aggressive as the Porsches we rented last summer in Germany

 

[Musky Mike]

Thanks for those links Mike. I don't believe my issue is a drone per se. It's not related to any specific gear or speed. This is a vibration at very specifically 1900 rpm in eco mode under load. I can feel it in the gas pedal, my seat, the cab. I know it's Eco mode because the second I hit the gas or gear selector to disengage Eco mode it stops.

That's what mine was doing, it's an ANC problem. It is ANC feedback through the speakers in your radio. Put your hand on the lower door panel next time and you will feel the vibration coming out of the speakers (like how too much bass will make things vibrate). It's most likely a glitch in the software. That's why a lot of owners have given up and pulled the wires to the ANC mic feeds to the amp or installed the ANC mic bypass harness.

 

[RBinNC]

That's what mine was doing, it's an ANC problem. It is ANC feedback through the speakers in your radio. Put your hand on the lower door panel next time and you will feel the vibration coming out of the speakers (like how too much bass will make things vibrate). It's most likely a glitch in the software. That's why a lot of owners have given up and pulled the wires to the ANC mic feeds to the amp or installed the ANC mic bypass harness.

The tech replaced my dampeners and said the software is all up to date. That didn't help. I can feel it in the steering wheel and gas pedal. I believe it's more than that but I'll feel the door panel like you say to see if it's worse.

 

[RBinNC]

Hello RBinNC,
We are certainly sorry to hear about your ongoing concern. If you are interested in getting connected with a Case Specialist that can work with your dealer to help find a potential solution to this, please reach out to us privately with your VIN and we can get started on that process.
Laura
RamCares

Laura that would be fine with me, however, the lead tech at the dealership told me he's done everything possible for a fix. I want Chrysler engineers to take note and work on a fix. I'm not the only person experiencing this.

I personally don't think it will ever be fixed as it's a design flaw in the balancing of the engine in MDS mode. But, maybe I will be proven wrong.

 

[JoeCo]

Laura that would be fine with me, however, the lead tech at the dealership told me he's done everything possible for a fix. I want Chrysler engineers to take note and work on a fix. I'm not the only person experiencing this.

I personally don't think it will ever be fixed as it's a design flaw in the balancing of the engine in MDS mode. But, maybe I will be proven wrong.

If it's mds related it's not likely as people have been barking up that tree for the last 10+ years. Also, ramcares is excellent at setting up appointments, beyond that I wouldn't count on them too much. It's a nice sounding name though.

Otherwise you may just want to join those of us who go into manual mode each time we drive to eliminate the mds, a little bit inconvenient to do it every time you put the truck in gear but it's worth it to keep in v8 mode.

 

[Musky Mike]

The tech replaced my dampeners and said the software is all up to date. That didn't help. I can feel it in the steering wheel and gas pedal. I believe it's more than that but I'll feel the door panel like you say to see if it's worse.

If the vibration is very repeatable, you could ask the tech to reload the software (from the sounds of it, he just checked to make sure the software was current) and then drive it and see. Could be the software load shows it's good, but it didn't load right. You could also try one fill up with premium gas (assuming your are using 87 octane now), maybe during MDS the engine is pinging and the ANC mics are picking it up and trying to counter act it. It's a long shot, but easy to try.

 

[RBinNC]

If the vibration is very repeatable, you could ask the tech to reload the software (from the sounds of it, he just checked to make sure the software was current) and then drive it and see. Could be the software load shows it's good, but it didn't load right. You could also try one fill up with premium gas (assuming your are using 87 octane now), maybe during MDS the engine is pinging and the ANC mics are picking it up and trying to counter act it. It's a long shot, but easy to try.

I got high test from the dealer when I first got it. Same issue. Going back to swap the chrome grill, had a defect in it that won't buff out