MDS Growl

[Mojo88]

They use a viscous/oil filled motor mount to dampen engine vibrations

Ahhh, another great tidbit of info from the Forum Master, had to correct the spelling though, haha................

 

[Wild one]

Ahhh, another great tidbit of info from the Forum Master, had to correct the spelling though, haha................

Spelling was never my speciality

 

[dieselscout80]

Do Rams have Active Motor Mounts to hide the vibrations during MDS? Some manufacturers use motor mounts that electronically produce vibrations to cancel the MDS vibrations. One of these mounts can be perfect mechanically, but allow MDS vibrations.

The 2019 and above HDs have active cab mounts.

 

[Lysergic]

When the MDS on my new-to-me 2012 5.7L kicks in, I can attest to the "old farm tractor" sound. I've been turning it off using the gear limiter method. Mileage suffers, but the truck drives (and sounds) better.

If I was planning on keeping the truck long-term, MDS would be going bye-bye permanently.

 

[Mike Wenrich]

Been working all weekend so late with this reply. Musky Mike nailed it. I turned the radio volume down and the noise went away. I can still feel a slight vibration when the MDS kicks in but otherwise no noise. So the harness will be on order soon. Thanks to all who replied. Good to know I'm not looking at another visit to the dealer.

 

[Tazwatson]

OK, just want to add a bit to this conversation and it may shed some light on the original posting where he had 4000 miles before hearing the growl. I have 26000 miles on my 2023 Laramie and noticed the Growl less than a month after I picked it up. Mine hade been in the shop for a recall so I was in a loaner for 5000 miles (long story). So this has been my troubleshooting to date. This seems to happen when the outside air temp is above 80 deg F. the hotter it is outside the louder and more pronounced the growl is. I do not here it in the winter or it has not been loud enough to notice for me. The noise is only present for me at ~1250 RPM. You can here it come in and get louder as you near that RPM and in ECO. as the RPM's drop below it goes away by 1100. It will also goes away as soon a ESR used to disable ECO. The growl is very load at 1250 and ECO if the air temp outside is 90 or above. Drove me crazy the first vacation I went on and was driving stop and go where I would get to speed and then let off as soon as ECO would come on and I was at that RPM it sounded like a Bass Strum from the SuB Woofer. Tried to get the dealer to look at it late last year but they could not reproduce the noise. Made me mad but It was getting had for me to get it to do it as well because the temps outside were dropping for fall and winter. I did not figure it all out till this year and by now the days are iffy for hot temps. Thats just what I have found. It is odd that it only happens at a certain RPM and in hot outside air temps. I hope there is a RAM rep out there that can take this information and run with it. I would have thought by now there would be a TSB or something. My be that most RAM owners Drive it like they Stole it (me to) and never have an issue. Or at least notice the issue. RAM, please look into this. It is bad when we have to do our own troubleshooting and still can't get anyone at the dealer to understand. There are some good troubleshooters out there, but you never know where to find them. Hope this helps. BJ

 

[Marshall]

could it be something to do with E- torque? I have never had that problem on my older ones, I can only hear it switch if the radio is down and the window down, diddling around town, we have a long hill I drive up going home and I can hear it switch back to 8 cyl. I am at 50km/30mph +/- On the hi way all I can tell is the light is on ,or off.

My old ears are poor, so that could have something to do with how quite my truck is.
The Honda has a lot more road noise , but the front tires are almost in the cabin on those older CRV's

I just noticed that someone talked about the noise canceling and wondered about that.
I have the radio on most of the time when in the truck.

 

[joesstripclub]

Its funny this topic came up and when I was heading back home from camping last weekend, sure enough heard a weird growl during one MDS engagement but didnt hear it again. I know I wasn't crazy because my wife had the same "what was that" look at the same time I did. Forgot about turning the radio down/off at the time, but it didnt last long with the camper in tow and never did it again.

 

[Docwagon1776]

Rams also have frame dampers to combat vibration. Some have active dampers and some passive.

This shows the active:

RAMs Vibrate To Stay Smooth While Saving Fuel. Here’s Why - AEC

Did you know that our RAM 1500 DT models use small modules that send vibrations into their frame to make it quieter? Why you ask? To save fuel! Okay, that sounds very complicated, but it’s actually pretty clever – let’s explain. With a growing niche in the European market and the all-time...

www.aecsolutions.com

My truck has the passive, which are just bits of weight on a little arm. I *think* only pre-COVID trucks got the active ones, but maybe they went back to them eventually?