Thoughts and or suggestions

[RJ1972]

2023 2500 6.4 Big Horn V8 Hemi just a little over 1500 miles. Attached is a video of my issue/question.
Out of all my Ram trucks I've never felt this before. Basically at 35 or 65mph just trying to hold it steady at that speed. Ever so slightly applying pressurer on the gas pedal. I get this (best way to describe it) like I'm riding over rumble strips. You can hear it right at the end of the video. As well as see my phone shaking. It's not as heavy and as distinct as if you really were riding over them.
If I let off or increase the gas pedal it goes away. I can maintain this annoyance for quite a while. Also, if I put it into tow/haul it goes away.
Anyone have any ideas or thoughts on this?
Appreciate your time and help.

Video file was to big. Here's a link:

 

[ClawSS]

Is the Eco light on when this occurs? Do you think it is going into MDS mode creating a bit of vibration when running on 4-cylinders? If you give it a bit of gas, does it also go away?

 

[Dave01]

Kind of hard to tell in the video. Like Claw suggested, I'm pretty sure you're feeling it go into eco mode with cylinder deactivation. Stepping on the gas would make it go away, tow/haul would make it go away, so your description seems to be a match for eco mode. Use your shift paddles to put it in 8th and I think you won't feel it during that time driving. It's a pain since every time you shift out of drive you have to again use the paddles, but a good way to make sure it's the cylinder deactivation you are feeling.

 

[RJ1972]

Kind of hard to tell in the video. Like Claw suggested, I'm pretty sure you're feeling it go into eco mode with cylinder deactivation. Stepping on the gas would make it go away, tow/haul would make it go away, so your description seems to be a match for eco mode. Use your shift paddles to put it in 8th and I think you won't feel it during that time driving. It's a pain since every time you shift out of drive you have to again use the paddles, but a good way to make sure it's the cylinder deactivation you are feeling.

That's kinda what I was thinking too. Never had this issue or feeling with my 16 PW or my 19 Rebel. Just really odd to me.
Don't believe I have shift paddles anywhere. It's a turn knob. Unless there is something I'm not aware of.
Appreciate the response.

 

[Jimmy07]

I think that’s what you are experiencing too- MDS.
Your description sounds like you’re coasting along in 4 cylinder mode, and when you apply throttle, you’re right in that area where it’s not enough to bring it back into 8 cylinder mode.
Tow/haul stops it from going into 4 cylinder mode.
If you have fuel saver display in cluster checked in the radio settings, the green “ECO” indicator will be on when MDS is active.

This feeling is mostly mitigated on the 2019+ rams with the active tuned mass modules on the frame behind the front wheels, but some trucks they were eliminated because of parts shortages.

 

[RJ1972]

Is the Eco light on when this occurs? Do you think it is going into MDS mode creating a bit of vibration when running on 4-cylinders? If you give it a bit of gas, does it also go away?

Yes, slightest change in gas goes away. Unsure on Eco. I apologize, i should have noted V8 hemi.
I'm thinking mds too. But my last 2 Rams never did this. Just hoping something isn't failing this quick. Had enough issues with my16 PW. Hated to let her go, but warranty was running out to keep her.

 

[RJ1972]

I think that’s what you are experiencing too- MDS.
Your description sounds like you’re coasting along in 4 cylinder mode, and when you apply throttle, you’re right in that area where it’s not enough to bring it back into 8 cylinder mode.
Tow/haul stops it from going into 4 cylinder mode.
If you have fuel saver display in cluster checked in the radio settings, the green “ECO” indicator will be on when MDS is active.

This feeling is mostly mitigated on the 2019+ rams with the active tuned mass modules on the frame behind the front wheels, but some trucks they were eliminated because of parts shortages.

Haven't noticed any Eco light. I'll definitely keep an eye on it on the way home tonight. I'll also check on fuel saver.

 

[Dave01]

I'm calling them paddles, but really they are + - buttons on the side of the steering wheel at about 4 o'clock. I believe every truck has them.

 

[RJ1972]

Appreciate it.

 

[Firebird]

Back and forth from MDS mode

 

[RJ1972]

Haven't noticed any Eco light. I'll definitely keep an eye on it on the way home tonight. I'll also check on fuel saver.

Ok, @Jimmy07 I found the Eco light to turn on. Worst mistake on my part. Yes if that light comes on and I hold steady pressure on the gas pedal (almost like an eighth inch down). I notice it and time it switches. 65 is really annoying with that cavitating feeling. This can't be normal. Like I stated I can hold it there and it doesn't stop.

 

[RJ1972]

I'd just like to say thank you to everyone. I did a little more research on. Yes, MDS. So, Now when I get in the truck. I have to put it to Drive, hit Gear Limit - then just hit the gear limit + till I get to 8.
Feels a lot better now.
Appreciate you all!!

 

[Dave01]

I use the gear limit maybe 70% of the time. After first starting in the cold I figure I don't want MDS activating, so do it then, or on trips where I just don't want it activating and deactivating over and over. But other times I just let it do it's thing, doesn't bother me. What I can't get straight in my mind is whether, for the least MDS caused potential problems, it's better to never let it activate, or is it better to allow it to activate some of the time so it's "exercised" on a regular basis. I don't expect anyone to have the answer to that one, but interesting to think about.

 

[Jimmy07]

I use the gear limit maybe 70% of the time. After first starting in the cold I figure I don't want MDS activating, so do it then, or on trips where I just don't want it activating and deactivating over and over. But other times I just let it do it's thing, doesn't bother me. What I can't get straight in my mind is whether, for the least MDS caused potential problems, it's better to never let it activate, or is it better to allow it to activate some of the time so it's "exercised" on a regular basis. I don't expect anyone to have the answer to that one, but interesting to think about.

There is someone that addresses exactly what you’re wondering. He shows and explains why it actually is the worst thing you can do is to disable MDS all the time (and that disabling it on a cold engine doesn’t matter because the engine needs to be warmed up as one of the requirements for MDS to activate).

 

[Dave01]

Thanks, Jimmy, I'll watch that a bit later. I know what you're saying about the parameters on a cold engine, but on mornings where I've remote started, then a couple of minutes later got in and drove away while it's still warming up, I've felt it activate (plus the eco light) before it's IMO fully warmed up.

 

[pizzatots]

Ok, @Jimmy07 I found the Eco light to turn on. Worst mistake on my part. Yes if that light comes on and I hold steady pressure on the gas pedal (almost like an eighth inch down). I notice it and time it switches. 65 is really annoying with that cavitating feeling. This can't be normal. Like I stated I can hold it there and it doesn't stop.

65 MPH is when it is the worst is my truck as well. 3.73 gears.

 

[RJ1972]

65 MPH is when it is the worst is my truck as well. 3.73 gears.

Ya, I just learned if I'm on a highway staying around that speed. I reach over a hit the tow/haul. It's just to annoying not to.

 

[pizzatots]

Ya, I just learned if I'm on a highway staying around that speed. I reach over a hit the tow/haul. It's just to annoying not to.

Mine sounds like it’s coming out of the passenger side more than anything else. I wonder if the tuned force dampers aren’t performing correctly

 

[pizzatots]

Researching this when I received the truck, almost a year ago, I came across: https://static.nhtsa.gov/odi/tsbs/2022/MC-10221444-9999.pdf

This calls out "With wiTECH navigate to AVC Misc Function and perform the “AVC Transfer Function Routine” with doors closed, Key On Engine Off. Please give 15 to 20 seconds of time after the dampers stop vibrating."

I havent taken it in to the dealer.

 

[RJ1972]

Researching this when I received the truck, almost a year ago, I came across: https://static.nhtsa.gov/odi/tsbs/2022/MC-10221444-9999.pdf

This calls out "With wiTECH navigate to AVC Misc Function and perform the “AVC Transfer Function Routine” with doors closed, Key On Engine Off. Please give 15 to 20 seconds of time after the dampers stop vibrating."

I havent taken it in to the dealer.

Please let me know what happens. Appreciate it.