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2020 Ram 1500 DT 5.7 MDS

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Hello all,

i was curious if i should get a MDS disconnect for my ram... It currently has 47,*** on the clock and I'm not sure if it has ever had it disconnected as i bought it used. Would it be wise to disconnect it now or leave it as it may have already done the damage and now its just the waiting game? If so, Please point me in the direction of what y'all use for that (whats best). I know you can get them built in to EDGE tuners, however i'm not sure if i want to go that route yet... Unless I should?

Note: truck is currently stock but will soon be getting aFe manifold just for peace of mind sake, stock manifold is currently fine.

Thanks 🤙
 

mikeru82

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Most of us just disable it with the "shift buttons" on the steering wheel. Requires you to do that every time you shift into D, but after a while it becomes muscle memory. Like putting on the seat belt.

I'm curious to know what damage you're referring to. Lots of people have claimed the MDS system causes damage, but I have yet to see creditable proof of it. I disable it because it's noticeable to me, especially with an aftermarket exhaust.
 

CHeYeNNe71

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There has been guys that have shut off MDS since new and still ate a motor. I shut if off because it's irritating and I change the exhaust and don't want to listen to it.
 
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Most of us just disable it with the "shift buttons" on the steering wheel. Requires you to do that every time you shift into D, but after a while it becomes muscle memory. Like putting on the seat belt.

I'm curious to know what damage you're referring to. Lots of people have claimed the MDS system causes damage, but I have yet to see creditable proof of it. I disable it because it's noticeable to me, especially with an aftermarket exhaust.
I have just read about lifter damage but im also going to be doing a exhaust on the truck and would rather not listen to that 4 cylinder tone lol How do you disable it with the shifter? Thats something i haven't read about.
 

mikeru82

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If it's MDS that causes the lifter issues, why do those issues happen on non-MDS cylinders and non-MDS Hemi engines? It seems to me that if MDS caused cam/lifter issues it would only affect the cylinders which are deactived by MDS.

There are a couple of ways to temporarily disable MDS. Putting the truck in tow/haul mode will disable MDS on 5th gens. This also changes shift points so your fuel economy can be negatively affected. The other way is to shift into D, then press the minus shift limit button on the steering wheel, then press the plus button until the gauge cluster shows 8 for the max gear it will shift into. Aternately, you can wait until you get up to speed and the transmission is in 8th gear, then press the minus button. There are tons of videos and explanations online for how to disable MDS if that's not clear enough for you to follow.
 

Darksteel165

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You can unlock the PCM and tune MDS off, but you still have MDS lifters so still a higher chance of failure unless you replace it all.
There is no such thing as a "disconnect".

Look up MDS delete kits and you can look around for pricing.
 

mikeru82

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You can unlock the PCM and tune MDS off, but you still have MDS lifters so still a PERCEIVED higher chance of failure unless you replace it all.
There is no such thing as a "disconnect".

Look up MDS delete kits and you can look around for pricing.
Fixed it for you.
 

bigdodge

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I have just read about lifter damage but im also going to be doing a exhaust on the truck and would rather not listen to that 4 cylinder tone lol How do you disable it with the shifter? Thats something i haven't read about.
The only way to "disable" MDS without aftermarket means is to select "8" on the gear limit (buttons in the lower right of the steering wheel) or select Tow/Haul
 

Belvedere

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I seem to be hearing more about lower oil pressure at idle keeping oil from the upper end. Thus many guys say to change oil often and don't idle extended periods, but still no definitive cause.

Unfortunately, I'm still running stock exhaust, so I just let it go into 4 banger mode.
 

Darksteel165

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Fixed it for you.
Right.
All those busted mds lifters and several companies recalling trucks that have mds sometimes while they sit on dealer lots unsold is all fairy dust. MDS is a perfect system that saves 99.9 mpg and makes the truck last longer with no downsides whatsoever.
 

Belvedere

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I seem to be hearing more about lower oil pressure at idle keeping oil from the upper end. Thus many guys say to change oil often and don't idle extended periods, but still no definitive cause.

Unfortunately, I'm still running stock exhaust, so I just let it go into 4 banger mode.
I should also say that after nearly destroying her Honda 3.5L based on their bad design, my wife keeps telling me to disable multi-displacement on all our vehicles.
 

mikeru82

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Right.
All those busted mds lifters and several companies recalling trucks that have mds sometimes while they sit on dealer lots unsold is all fairy dust. MDS is a perfect system that saves 99.9 mpg and makes the truck last longer with no downsides whatsoever.
Thanks for putting words in my mouth. In case you missed it I disable MDS every time I drive the truck. I am not a fan of it, nor have I seen any fuel savings with it when I used to let it do its thing. But the lifter/cam issues people have has not been proven to be caused by MDS. There have been plenty of failures on non-MDS lifters too. Or have you just decided to ignore those because they don't fit your narrative?
 

6of36

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From what I have seen, it's the normal lifters that go, not the MDS lifters. It's the needle bearings that go, then it wipes out the cam. Keep clean oil, and avoid excessive idle times.
 

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