6.4l Hemi MDS Vibration

[keeperofthecode]

The vibration when MDS kicked in on my truck had gotten very bad. A buddy rode with me was wondering if my truck was fixing to break down so I figured it was time to get it checked out. Three trips to dealership later I'm pretty sure they just turned MDS off after swearing to me that they did not. They kept tuck for a week each time and put hundreds of miles on truck and each time said a computer update fixed it. MDS cannot be noticed at all now, magically better than when truck was brand new. Gas mileage is down about 1.5 mpg on average. Is there any way for me to tell if the MDS has been disabled? I'm really frustrated with dodge dealership and feeling like they are being dishonest.

2014 Dodge 2500 6.4l Hemi

 

[Iron Outlaw]

I wish they'd turn mine off.

 

[mtofell]

I've had my truck for nearly 3 years and am pretty in tune with what my vehicle is doing. I've never had any idea how to tell if/when the MDS is on or off. My wife's Honda Odyssey has a light on the dash. I'm not sure how you'd ever know on the Ram.

 

[keeperofthecode]

Before they possibly turned MDS off you could tell by everything in the truck rattling when it shuts off four cylinders. Literally change in the center console is jingling.

 

[DILLIGAF]

On the 1500s there's an eco light that comes on in the cluster

the eco light on the 1500 has nothing to do with MDS

 

[Tach_tech]

First off there is no way to disable MDS with a factory scan tool. Second there is a flash update for the 6.4 trucks that adjusts MDS operation to help reduce the drone/vibration.

As for the ECO light, that does not mean MDS is operating.

 

[RamInfo]

I always know when my MDS is engaged, due to the distinctive droning noise and the flat response to a slight increase in throttle. A touch of hemi foot fixes both...

 

[reek]

if you're still convinced it was turned off, an easy but expensive way to tell would be to remove your muffler and put an after market can on, like the mufflex. you can definitely hear the MDS fart noises more distinctly. or maybe try driving around with the resonator off? not sure if that would be enough to amplify the sound.

 

[smurfs_of_war]

No matter how smooth the transition is, you should still be able to feel and hear (if you have good ears) when MDS kicks in. The Eco light isn't indicative but usually will come on with MDS.

That said, the sound is unmistakable and the feel is too. You can feel the slight change in the truck, and when it fires the other 4 cylinders up, you should feel that. If you don't, something is weird. NEVER had one (of the 3 I have had with MDS) go in and out without being able to notice it. I kind of suspect that it has just smoothed it out enough that you are not really noticing it now since your senses to it were dulled so much by the previous vibrations?

I think if they did disable it on you they would have done it with an aftermarket tuner. If they did, they are shady as ****. I really don't think they'd put themselves in that kind of situation though.

 

[Hootbro]

Pretty sure there is a TSB out on 6.4 MDS and excessive vibration. IIRC, the fix was a new motor mount.

I am at work but I will check when I get home later tonight as I think I saved a copy of the TSB on my home computer.

 

[keeperofthecode]

One other thing is I could usually tell by watching the instant MPG maxing out as to when the MDS engaged. I no longer can see it having a major jump as it did before. I know the dealership has a way of turnign off MDS because it was the first solution they offered me once they proved the MDS was the cause of the vibration.

 

[Rzrman328]

That said, the sound is unmistakable and the feel is too. You can feel the slight change in the truck, and when it fires the other 4 cylinders up, you should feel that. If you don't, something is weird. NEVER had one (of the 3 I have had with MDS) go in and out without being able to notice it.

THIS.

I don't see how one couldn't notice it. Mine definitely vibrates more when it goes into fart mode.

 

[RamCares]

The vibration when MDS kicked in on my truck had gotten very bad. A buddy rode with me was wondering if my truck was fixing to break down so I figured it was time to get it checked out. Three trips to dealership later I'm pretty sure they just turned MDS off after swearing to me that they did not. They kept tuck for a week each time and put hundreds of miles on truck and each time said a computer update fixed it. MDS cannot be noticed at all now, magically better than when truck was brand new. Gas mileage is down about 1.5 mpg on average. Is there any way for me to tell if the MDS has been disabled? I'm really frustrated with dodge dealership and feeling like they are being dishonest.

2014 Dodge 2500 6.4l Hemi

Hi keeperofthecode,

There is a TSB that includes a Flash update (computer update) which might be what your dealership performed to fix your vibration concerns:

"NUMBER: 18-096-16
GROUP: Vehicle Performance
DATE: August 19, 2016

SUBJECT:
Flash: 6.4L Diagnostic And System Improvements

SYMPTOM/CONDITION:
NOTE: **This bulletin contains optional software update that should only be used in situations where the customer is specifically complaining of a Drone Noise, Shudder, Pulsation, or Vibration under light throttle applications while vehicle is operating in MDS/ECO mode.

A small number of customers may experience a surge, shudder or pulsation type sensation when driving on smooth road surfaces at highway speeds of 64-129 km/h (40-80mph).**"

If you are still experiencing concerns with your vehicle I would recommend visiting your dealership for further diagnosis. Please let me know if you have any additional questions!

Andrea
Ram Social Care Specialist

 

[Hootbro]

Here is the TSB for the motor mount.

 

[keeperofthecode]

Thanks for all the good info. If I take my truck to a non factory shop with a snap on scanner for instance would they be able to tell if the MDS has been disabled? As I suspect it has I will make the dealer turn it back on then show them this bulletin. A complaint to dodge will probably accompany all this.

 

[keeperofthecode]

Took my truck to a different shop today and they gladly hooked the truck to their scanner and went for a test drive with me. The MDS is in fact still working. They just have it set so that it almost never engages. Before in flats and even slight uphills at slows speeds the mds would engage. Now the only time it goes to MDS is when going down hills and all acceleration has stopped for the most part which is why I never hear or feel it engaging anymore. It is not as bad as I thought which was that they just turned it off but I'm still not happy with the results. I bought the truck with expectation of getting a certain MPG, MPG that is gone now with this new program. Am I being unrealistic in my expectations that RAM should fix this without me having to sacrifice MPG?

 

[smurfs_of_war]

I guess I'd have to wonder where the bar for acceptible fuel economy is in a 7000lbs truck with a 6.4L? I am not being snarky, I am being serious. The HDs are not rated by the EPA for a reason. Sound like your MDS is acting exactly like mine now. Rarely on unless it's highway. I stopped tracking and quit with fuelly.

I don't think it's unreasonable if there's an actual problem but it really doesn't sound like there is now.

Sent from my SM-G925W8 using Tapatalk

 

[keeperofthecode]

It's easy to dismiss 1.5 MPG I guess but if you think about it that is a 10% reduction in fuel economy compared to what I'm used to. Fuel isn't so bad right now but think about over the last ten years how much you spent on fuel and add 10% to that number.

Or lets go one step further. I drive the hell out of my trucks. The last one I drove to 300,000 miles. Thats 270,000 miles away and fuel is running about $2 a gallon right now.
270,000 miles / 14mpg = 19,285 Gallons of fuel x $2 a gallon = $38570
270,000 miles / 15.5mpg = 17,419 Gallons of fuel x $2 a gallon = $34838

That little change in the programming will cost me over $3700 and just imagine if fuel goes back up to $4 a gallon.

 

[smurfs_of_war]

I get where you're going, but I am not trying to dismiss it. I am genuinely curious where the bar is set. I average about 21l/100km- 11.2mpg for those south of the border. That is pretty much all stop and go city driving. When I hit the highway I average 13l/100km (unless I am pulling or bucking a wind). Is that good? I don't know because the only thing I can compare it to is my half tons and that's not even a comparison and there is no EPA rating to tell me if it's **** or not.

So, if there's a problem- yes. Ram should fix it. But if all systems check out then what's to fix?

I am sympathetic to your cause. When a CEL disabled my MDS for a few weeks I sure as hell noticed.

Sent from my SM-G925W8 using Tapatalk

 

[keeperofthecode]

No worries. Sounds like your getting around 18mpg on highway which is where I used to be.

That's Ok though Dodge, I'll just make one of my kids pay their own way through college. Problem solved. Now I just have to figure out which one is getting the bad news.