Does MDS/Eco cause a small jolt?

[Vapor567]

I thought I read MDS and the little green ECO light are separate instances. However, when I accelerate slow it seems I feel a little jolt, almost like a very hard shift. Is this normal?

 

[Squatch]

Yeah, you can definitely feel the transition in and out of it, I don’t notice it on the highway, but around town it just feels a bit clunky coming in and out of MDS.

 

[Deleted member 80]

For sure, on my '15 it did.

 

[RainDesert]

When my 2019 came in and out you could tell around town. Coming out sometimes felt like a shift.

 

[MikeXM]

I read some turn it off because it is annoying.

 

[Vapor567]

Thanks guys, guess a clunk is the best description. I only feel it going in the eco mode around town, I've yet noticed it on highway or when it turns off.

 

[JinwA]

Just a clunk sometimes right after I first start driving the truck. Comes from the area where the frame noise canceller is located. It’s like it is out of synch or something. A couple of bumps then nothing after that. I don’t notice anything like a shift.

 

[Ruffone]

You guys must be real sensitive, I have yet to feel mine going in or out of MDS mode. My truck shifts smooth to the point that most of the time I don’t feel the tranny shifting at all, now when I get on the accelerator real hard that’s a different story.

 

[Squatch]

Yeah, I cry a lot... I’m not even sure why.

 

[JinwA]

The clunks I referred to was when I got in fired it up and left. Accelerated around a corner and clunk, clunk, clunk. It has only happened 3 times. I could wait about 30 seconds and do the same thing and no clunks. Again you can feel it as well as hear it. I had a friend wack the frame with a rubber hammer with the engine off next to the canceller and that is where the sound/vibration was coming from. Just give the system time to initialize.
And as to crying....The things that made it past QC at the factory and at the dealer really ticked me off. It should, the price wasn’t cheap.

 

[Gondul]

A slight 'shudder' from time to time, but certainly not a 'jolt' or 'clunk'...

 

[JinwA]

My 2007 Ram STD had a 5.7L first year of MDS. It had an annoying 1-2 sec delay if you accelerated as the other 4 cylinders came back online. You also had to be In OD and steady state for around a minute. Really woke me up the first time I went to pass on a narrow 2 lane and no instant power.
Not the case with my 2019. It is very smooth, no delay and goes into eco more often and stays in longer.

 

[Kimo7]

Yeah, you can definitely feel the transition in and out of it, I don’t notice it on the highway, but around town it just feels a bit clunky coming in and out of MDS.

+1 - it’s subtle but I also feel sometimes, it’s random, a little more pronounced at times than others in both feel and sound. And that’s pretty dang funny... I cry a lot and don’t know why...

 

[Distillusion]

I would never call mine a clunk or even a shudder. Just a very minor vibration and a slightly audible change in the pitch of the exhaust as it kicks in. When it kicks off, I feel a very slight delay in spool-up when I'm accelerating hard. But in normal driving, the delay is not noticeable. The delay is not really due to mechanicals in the MDS, but to the air intake. When it kicks off, it does it in less than a single engine revolution. It starts allowing air/fuel into the cylinders in a few milliseconds. That means the engine starts sucking double the air mass than it had been, and that has to be pulled through the air filter. It's not much difference, just a few more milliseconds, but it's just enough to feel sometimes.

 

[JinwA]

The noise canceling is part of the MDS system. The clunks were always associated with that part of the system. Out of synch initialization best I can tell. Never repeated during the same trip. Just at the very beginning.