Is it Enough to Disable MDS via Gear Limiter?

[stickabee]

I've never been a "car(truck!) guy", but a year ago my wife got a new Wrangler and I found myself interested in the various aftermarket parts and modifications, which led me down a rabbit-hole of understanding the various components of these automobiles. I've got a lot of years of know-how to catch up on, but I've got an engineer's need to understand how things work, so I'm committed...

I've always maintained, in conversations with my wife, that we need a truck on our little hobby farm and so, this month during the 0% APR incentives, I started looking hard at replacing the '14 F-150 with 3.5L EcoBoost that we had (her purchase decision, at the time). I was always concerned that the turbo was just a ticking time-bomb and I could never just be content to let that potential problem brew. I wanted as "simple" a powertrain as I could get in a truck buy because, despite wanting to get rid of a 2014, we're not usually compulsive car-replacers, and I intend for the truck to last long-term. I looked closely at the F-150 and the 1500 and found myself pulled more toward the 1500 for a couple reasons, so we pulled the trigger on that. Of course, after the fact (my fault entirely), I read that I may have replaced my concern about the EcoBoost turbo with a new concern about Hemi MDS...

So now I've been trying to educate myself about what it is, what are the possible causes, and the possible risk mitigation stuff. I always resent having to turn off the ridiculous automatic start-stop in my wife's Jeep every time I power it up, but now it looks like that may become a ritual in the 1500 with the gear limiter, but that makes me wonder about the MDS lifter failure itself. It seems to me, in my layman's analysis of the issue, that it's LIKELY to be related to a mechanical failure in that spring lifter plunger mechanism preventing it from preventing (phew!) the lifter from moving the rod. I guess, if that IS the failure mode, then disabling the MDS via the gear limiter should prevent the failure and subsequent damage. I'm willing to commit to doing this as a long-term experiment, but I'm wondering if there are other thoughts on the MDS failure that AREN'T likely to be affected by "disabling" MDS in this way. I guess if the issue is related to oil flow and viscosity, the disabling via the limiter isn't going to do anything, right?

I know a definitive answer is going to require a definitive answer on the failure, which isn't very likely...

I've been reading a lot about the MDS issues, and it's dulled my excitement for the Ram. Having said that, every time I fire up that Hemi I get a renewed enthusiasm for it, so there's that.

 

[jdefoe0424]

A lot of what I've read says it's related to lots of hot idling time. Which, to me, means it's an oiling issue and not an mds issue...if that's really true. Though I haven't done a ton of research on it myself.
So if that's the case it may be a better solution to figure out how to increase the idle speed or increase idle oil pressure if yours is low.

For me, I'm going to use high quality Amsoil and a wix or Amsoil filter and drive it and let the truck function how it was designed. Sure it's slightly noticeable/annoying when it kicks in and out but I'm used to it after 10k, and even though we didn't buy trucks for their gas mileage it does help the wallet a tiny bit.

Sent from my Moto Z (2) using Tapatalk

 

[User_3336]

My truck has NEVER seen MDS, and never will. Previously hated it in a previous model year, and still hate it.

Its not quite as bad as AFM on a GM V8.

When I'm up to speed on the road, I just hit (-) once, its already in 8th, and MDS never comes on.

 

[jkm312]

This is the second truck I've owned with MDS. The first being a 09 Silverado, 5.3 litre engine , the second my 19 Ram. In the GM I never knew when the MDS kicked in, never felt or heard a thing. I heard and felt several other issues with the GM, but never the MDS.

With the RAM it takes awhile to fully understand where all the adjustment choices are, at least for me it did. There is a lot of tech to digest and operate. If it wasn't for the green eco light on the dash I wouldn't know when it is on or off in this truck. I drive the same roads for the most part and my driving style has not changed much. Except once in awhile in the on ramps, I like to light the Hemi up just for the hell of it.

As with any machine you have to operate it within it's design capabilities, and . . . . . maintain it. MDS isn't anything new, been around for quite awhile. There will always be no matter what brand of truck you decide on, a very small percentage of lemons (09 Silverado for me). If you max the machine out all the time, you will find the weak spot, if it has one. If you baby it all the time, that's just worse in my mind.

I would encourage you to drive your truck reasonably, and pay attention to it. Use top shelf oil and filters, change it regularly. Buy decent gas. If it isn't broken don't fix it. If it does brake, fix it.

Don't let some of these forum posts take you down the dark side chasing ghosts that are not in your truck. That doesn't mean everyone of these trucks are perfect, because a few are definitely not. It's frustrating if you have one of those trucks (09 Silverado).

I've had some minor issues that were resolved. Tailgate straps different lengths, AC evacuated and recharged full, AC software reflashed late last summer, driver's outside mirror replaced because it was loose. AC is still working as it should. I didn't know what to expect at the start of the AC season this year, but it's a non issue for me. The engine and drive train, the heart of the truck, is rock solid.

For my part, this DT is the most comfortable and fun to drive truck I've owned. NO regrets about buying one. I let the truck do truck stuff, and I do the driver stuff. It flat out works.

Hope your experience is as good or better than mine. Enjoy the truck.

 

[User_3336]

Tailgate straps different lengths, Check, mine too. and I have squeaking noise right about my tailgate release.

driver's outside mirror replaced because it was loose. CHECK, passenger side....

 

[stickabee]

Don't let some of these forum posts take you down the dark side chasing ghosts that are not in your truck.

I appreciate that sentiment. I think it spoiled the F-150 for me, which was a decent truck, otherwise. Having said that, I'm pretty darn happy with the Ram; it's certainly world's more enjoyable to drive for me, at 37, than my Scion and I can't get over how much more contemporary the styling, interior, and ride-quality are than the Ford.

A lot of what I've read says it's related to lots of hot idling time. Which, to me, means it's an oiling issue and not an mds issue...if that's really true.

Yeah. The real bugger of the issue is that there's not a clear and definitive answer on what the actual failure mode is, so I guess we're taking stabs at it, in the dark. I'm an engineer, so I'm inclined to trust engineers and specs and such, which leads me to want to follow the manual guidance, but then, I've never been in a position where I had to worry about balancing fuel economy, part lifespan, and marketing buzz. It seems like a perfect storm of conflicting interests that leads to everyone compromising and no one being able to speak the absolute truth of the matter. I'm not saying there's a Ram-conspiracy to hide the truth from us, but I could see how we wouldn't be able to get too close to the thing.

My truck has NEVER seen MDS, and never will. Previously hated it in a previous model year, and still hate it.

I'm likely to go this route, myself, so it'll be interesting to see if the cam wear happens or not.

Thanks all. Looking forward to being an active member of the discussions here on the forums!

 

[Neurobit]

Welcome to the forum and congratulations on your new RAM! Glad to have you here.

Pls add your truck's vitals to your signature when you have a moment.
This makes it easier for other folks to help in case you have questions or concerns about your vehicle.

 

[Orion10182011]

Except for the eco light that I had to enable I can't tell when MDS is on or off. I doubt using gears to disable it actually accomplished anything.

 

[Neurobit]

Except for the eco light that I had to enable I can't tell when MDS is on or off. I doubt using gears to disable it actually accomplished anything.

Eco light signals MDS on or off. If you see it, it's engaged, if you don't, it's not. Note that in the previous gen RAMs it was a separate thing, but on the 5th Gens, that's what it is.
Yes, using the gear limiter will disable MDS (and therefore, the eco light).

Cheers,

 

[HydroRebel]

Here's a pic I took from my 2014 1500 Sport the day I traded it in. I don't know how accurate this is, but out of 2154 total engine hours, my truck spent 648 hours just idling which works out to 30%. I never had any issues with the truck during my 6 years of ownership. No tick, no strange noise, no riding rough and no failures. Not to mention where I work it seems like every 2nd person has some variation of a Ram 1500 and I haven't heard of anyone locally with cam/lifter failures. A large portion of my daily commute to work is highway driving, so MDS was engaged a lot. I don't doubt there's people out there who have issues, not at all, and it would suck if it's you, but based on my experience so far I have no problem recommending a Hemi engine. I read a lot of info throughout various forums, YouTube videos (especially Scotty Kilmer) and I say take it with a grain of salt. All auto makers have issues pop up. Such is life.

 

[Genxeration]

Except for the eco light that I had to enable I can't tell when MDS is on or off. I doubt using gears to disable it actually accomplished anything.

I guess it’s just a habit for me now but when I get in my truck I press the Tow/Haul switch. No MDS and I think my trucks shifts better that way. Probably hurts my fuel economy but with the Mopar lift and 35s I guess I’ve already killed my fuel economy