MDS question

[Brandon-w]

Actually...... Mds has been proven to fail time and time again with poor maintenance. Just do the research on mds lifter problems... I may not be an engineer but tell a guy who's built over 100 stationary engines and installed them and also had a mds lifter crap it's self. You can't tell me that the mds system is not the problem. Let's use Chevy for example considering they're now using an mds system. They're having lifters collapse on people, it hammers for a bit because people are not smart enough to know what it is. After some hammering it breaks the lifter retainer and twists in the bore grinding the cam to bits..... Chevy non mds engines = some of the stronger running engines around. So yeah tell everyone to use it but many failures can be linked to the mds system. There are also reasons that mds is disabled in tow mode and with tuners.... Just my two cents from a guy who just did one on his own. Beleive what you want though.

 

[Scottyshortbus]

Can someone tell me what cylinder #’s shut down while using mds? Mine is 2011 5.7L

 

[RVGuy]

Can someone tell me what cylinder #’s shut down while using mds? Mine is 2011 5.7L

1, 4, 6, and 7

 

[Scottyshortbus]

Thanks RVguy. Been wondering for a while but it’s easy to get lost in results when you search mds on here.

 

[boblonben]

Hey all,

I've had MDS turned off (manually by selecting gears) essentially since I bought my truck with 8 miles on the odometer. I had read somewhere that the MDS could cause damage to the truck, specifically the dreaded lifter failure.
That was almost 5 years ago and I've done quite a bit of reading (and driving, I'm at 158,500 miles now) since then and I'm not sure it's true. Is there any actual evidence that the MDS could be the cause of any long term damage to the engine? I mean the system has been out for, what, 14 years or so now? I'd think if it was some horrible thing there'd be huge uproar and widespread failures but I still see a lot of 3rd gens and pre-2013 1500s with the 5.7 rolling around here. Not to mention all the other vehicles with the MDS in them on the road.
I'm not trying to debate if the MDS really does anything for fuel economy. I've let mine run for a few tanks of gas here and there and for my driving style and commute is does actually make a worthwhile difference when I hand calculate my mileage. I'd like to just let the MDS run but I'm concerned about it doing harm to the truck. I want to milk as many miles out of this thing as possible before I buy another truck so to me longevity trumps fuel economy.

So, what's the verdict? Is MDS actually harmful to the hemi or is that an old wives tale made up because we just love to hear that V8 growl all the time?

the answer is NO , MDS causes NO problems with the engine and anyone who says so is full of crap. Actually the MD is beneficial - more than just mileage gain - as it allows the motor to perform less strained work overall, if it needs more work it then disengages itself. Of the cases I've heard and had actual hands on experience with MDS not working correctly is always the same thing - some idiot NOT using the correct weight motor oil, or letting the oil get so dirt does not allow the MDS function properly. Know one case where the MDS quit working, guy brought it in, claims to have been using the correct oil - yep he had the factory installed oil, at a mileage of use of 84556 miles !!!!!!!!!! No wonder it stopped working. He said the oil change digital gauge never indicated he needed to change it. Who knows about some folks. Have MDS engines in my cars and trucks(Charger R/T, Durango R/T, and RAM Sport 4X4), never had a problem with about 250K combined miles.

 

[boblonben]

And MDS always shuts down the same set of cylinder. Research show NO measurable difference between MDS cylinders and the non-MDS within the same engine Lots of research and testing here and a static set is easier to program than a variable set, less code to worry about messing up, and it does at times.

 

[Kukailimoku]

I'll always believe it's cheap bearings in the lifters.Companies taking bids on whoever will supply parts for the cheapest price is not always conducive to getting a quality part/product.

The old Army saying holds true here:
"Remember, your weapon was made by the lowest bidder"

(That's actually NOT 100% of the time; sometimes government can buy above lowest bid if they can prove better overall "value" over raw lowest cost)

 

[Kukailimoku]

I think it depends on the situation. On my current hemi which I still owe money on yeah Id definately trade if it gave me any more issues. On the other hand an older truck, that's paid off, dont owe me a thing and if the body is good I'd drop an engine in it knowing the money was well spent. It just makes sense, I'm not locked into $500+ a month payments for the next 5-8 yrs and I can throw cheap insurance on it and save money there aswell.

What's a new engine cost? 5 grand? 10 grand?

That still sounds like $500 bucks a month for many many months. Granted, not 7 years, but still, not chump change either. AND no warranty either.

(Honestly, I don't know what the new engine costs, I'm not being an asz)

 

[Bigskyroadglide]

My thoughts, MDS is an engineering marvel, one of those things designed, in theory, to help achieve an impact on the environment. However, it's impact, is truly unknown as the ability to turn it off and on again is available to everyone who has the desire to do so, and at will.

For it truly to be tested, the ability to turn it off must be addressed or it's just a gimmick.

If it's a gimmick, then there's little reason for it to exist except as a process to cause problems that requires service by the dealership or a reason to upgrade vehicles.

MDS or non MDS, I don't care, just build something that can run 150k miles, at minimum, and let me decide. Don't make it a crap shoot where the engine can fail at any time due to faulty parts and undetermined reason for failure.

My .02 cents.

PS. I'm non MDS, via a tuner, at 138k and have been non MDS since 82k when I started driving the truck. Never seen a measurable difference in fuel economy.

 

[Brandon-w]

What's a new engine cost? 5 grand? 10 grand?

That still sounds like $500 bucks a month for many many months. Granted, not 7 years, but still, not chump change either. AND no warranty either.

(Honestly, I don't know what the new engine costs, I'm not being an asz)

You being an ass? I couldn't tell. Lol[emoji13]

 

[Iiplus]

the answer is NO , MDS causes NO problems with the engine and anyone who says so is full of crap. Actually the MD is beneficial - more than just mileage gain - as it allows the motor to perform less strained work overall, if it needs more work it then disengages itself. Of the cases I've heard and had actual hands on experience with MDS not working correctly is always the same thing - some idiot NOT using the correct weight motor oil, or letting the oil get so dirt does not allow the MDS function properly. Know one case where the MDS quit working, guy brought it in, claims to have been using the correct oil - yep he had the factory installed oil, at a mileage of use of 84556 miles !!!!!!!!!! No wonder it stopped working. He said the oil change digital gauge never indicated he needed to change it. Who knows about some folks. Have MDS engines in my cars and trucks(Charger R/T, Durango R/T, and RAM Sport 4X4), never had a problem with about 250K combined miles.

 

[Iiplus]

In my case poor maintenance not the culprit. I changed with correct weight pup oil every 3500 miles all my maintenance on every vehicle I’ve owned performed well before recommended schedule. I am a 50 year automotive engineer. At 138K experienced cam lobes flat spotting. My 40+ mechanic said my engine the cleanest he had every seen. I’m **** so I replaced lifters, cam, push rods, timing assembly, machined heads, upgraded valve seats and springs.

 

[Brandon-w]

In my case poor maintenance not the culprit. I changed with correct weight pup oil every 3500 miles all my maintenance on every vehicle I’ve owned performed well before recommended schedule. I am a 50 year automotive engineer. At 138K experienced cam lobes flat spotting. My 40+ mechanic said my engine the cleanest he had every seen. I’m **** so I replaced lifters, cam, push rods, timing assembly, machined heads, upgraded valve seats and springs.

So that makes two of us for sure who have had failures and not due to lack of maintenance.... Anyone else I'd love to have a forum wide poll to see who else has had these failures that were not from lack of maintenance.

 

[scott lass 18]

Yeah compression test and try coil then. I'm so happy im in Canada. I deleted my emissions crap on my dodge. And refuse to do any recalls like the shift knob lol

thanks duaaaa dint think of that well coil here but problem s still there and every start so well see if I can do that find out right away I bet sooooo sucks engine light for years come on 15 mouths now no warranty left ! ochhhh 1 HEARING ITS 90 PERCENT A LIFTER AWWWW SUCKS

 

[RVGuy]

.If it's a gimmick, then there's little reason for it to exist except as a process to cause problems that requires service by the dealership or a reason to upgrade vehicles.

They get CAFE credits for having a cylinder shutoff system so in that sense it serves a purpose whether it works/can be shut off or not.

 

[OCDTech]

They get CAFE credits for having a cylinder shutoff system so in that sense it serves a purpose whether it works/can be shut off or not.

Same with start/stop, which is more bovine manure.


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[Bigskyroadglide]

They get CAFE credits for having a cylinder shutoff system so in that sense it serves a purpose whether it works/can be shut off or not.

Thanks for the clarification.

Then it is a gimmick and EPA work around without regard to long term engine viability.

Makes more sense to me now.

Appreciate the insight

 

[OCDTech]

Complexity is the enemy of reliability. Always


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[scott lass 18]

Actually...... Mds has been proven to fail time and time again with poor maintenance. Just do the research on mds lifter problems... I may not be an engineer but tell a guy who's built over 100 stationary engines and installed them and also had a mds lifter crap it's self. You can't tell me that the mds system is not the problem. Let's use Chevy for example considering they're now using an mds system. They're having lifters collapse on people, it hammers for a bit because people are not smart enough to know what it is. After some hammering it breaks the lifter retainer and twists in the bore grinding the cam to bits..... Chevy non mds engines = some of the stronger running engines around. So yeah tell everyone to use it but many failures can be linked to the mds system. There are also reasons that mds is disabled in tow mode and with tuners.... Just my two cents from a guy who just did one on his own. Beleive what you want though.

well work on a lot of things u r right ! i new it in the 60 s people playing with this and blowing up lifters all the time ! mine babyed amsoil tune and better then sooo many over ten year s mds off and guss what the sad po301 59,000 on it so did new plugs new coil sadly pops up 301 still so off to dealer soon ! was told my power train warranty well cover engine ! i had cover s it just did my last day 10 year warranty so ferecky sad sems a lifter ! wish my luck next year !

 

[Brandon-w]

well work on a lot of things u r right ! i new it in the 60 s people playing with this and blowing up lifters all the time ! mine babyed amsoil tune and better then sooo many over ten year s mds off and guss what the sad po301 59,000 on it so did new plugs new coil sadly pops up 301 still so off to dealer soon ! was told my power train warranty well cover engine ! i had cover s it just did my last day 10 year warranty so ferecky sad sems a lifter ! wish my luck next year !

Hopefully they get you figured out.