[Smokn05]

I recently bought a new left-over 2017 TA 392 with A8 trans. I specifically wanted MDS as I do almost all highway driving and it will be my daily driver. I've seen several Youtubers saying the 6.4 MDS lifters wear and fail often. I've also had several people tell me in person that all manufacturers are having early failures on MDS engines, Chevy, Mopar etc. due to lifter problems. That kind of worries me and makes me think of several questions about it and if there is anything I can do to help prevent MDS causing engine failures.

1) Are all 6.4L engines going to have mechanical failure due to MDS, its just a matter of time?
2) To prevent MDS failures, is it as simple as driving in Sport Mode all the time so MDS isn't engaged? Or will the MDS lifters still fail whether being in MDS mode or not?
3) I don't plan on modifying the engine or racing the car or really beat on it any more than an occasional on-ramp pull. So my plan was to run factory Pennzoil full syth oil, SRT filter and change it every 6k. (I drive 100+ miles a day all highway and its mostly spent on cruise control) I installed a BT catch can and got maybe 1" worth of oil out of it in the first 7k miles. Is there anything wrong with just driving it like I do, change oil at 6K and don't worry about any MDS failures? I have full warranty for 75k miles so if something does fail I'd assume a full repair would be covered under warranty.
4) Or should I do 3K oil changes and take oil samples to watch for wear like some people I've read about?

One of the reasons I got this new car was to stop driving older highly modified muscle cars and sports cars as a daily driver and having to constantly do maintenance on them or watch for the next thing to break. I was hoping this car would fill the need for a powerful and fun to drive sports car yet still be new and reliable. Thank you for any input. And long live Mopar!

 

[mr.cheez]

I don't have a good answer for you, but I do have a suggestion. Ever thought of buying an extended warranty? Many people on here have had luck buying lifetime warranties. I assume that mds would be covered in those lifetime warranties.

Sent from my Nexus 5X using Tapatalk

 

[canative]

This is not a Challenger but my '06 Ram with the 5.7 has MDS and 80K miles with no ill effects as of yet. Although I did buy a Diablo Predator to specifically disable the MDS.

 

[Joe B]

No it will not fail. Millions of vehicles from many car brands use the same system with very little problems. Just follow the recommended oil change interval the owners manual states, and use the oil viscosity it tells you to use. That's the important part, careful about using the right oil weight.

 

[Rockster]

Have to wonder how much benefit you'll get from MDS given your usage.


With my 2018 HC if I have the HP "gauge" showing cruising at legal legal highway speed the engine is only being "asked" to put out around 45hp to 50hp. Gas mileage is in the mid 20mpg range.


With these cars one can do pretty darn good with a light foot and reasonable cruising speeds when on the highway in helping the car deliver good gas mileage. The car will never beat a Prius in this regard but for a big high performance car it can do very well.



My point is if MDS doesn't really buy you anything given your usage you might consider disabling it. Thus you do not have to worry -- that much -- about the MDS portion of the engine causing problems.


Whether you decide to leave the MDS active or disable it as others have advised and I have to second this is to be sure to follow Dodge's oil change interval schedule -- or be a bit more OCD and change the oil more often -- and use the recommended oil.


No promises but I have driven big miles -- 150K to 317K miles -- in various cars and have followed the auto maker's oil change interval schedule (although in one case I cut it from every 15K miles (!) to every 5K miles and in another case from every 10K miles to every 5K miles) and used the oil the auto maker said to use and in every case have never experienced any internal engine problems. Regular oil/filter services go a long long way to helping an engine deliver a long and trouble free service life.


Might mention one of my two previous cars came with a very sophisticated variable cam timing and variable lift system. At certain times, under certain operating conditions, the engine controller would switch the intake valve lifters from high lift to low lift and back again. The automaker claimed to have tested this feature in over 250,000 cycles. I don't know how many cycles my engine experienced over 13 years but I it had 161K miles on it when I sold the car and the engine was in very good shape essentially like "new".

 

[BenchMarkVII]

i used to think "No MDS is a tried and trusted system" but since my failure 2 months ago, and research associated with it I have come to think that it is indeed an issue, not just for Chrysler but across each platform that uses a similar method of oil restriction/lifter deactivation.

Mine is a 126000 mile 2011 SRT8 Challenger that had a catastrophic failure on an MDS lifter, wiping out not only the lifter but the cam. Upon tear down (all done by myself) it was evident that the lifter/roller had experienced restricted oil flow leading to roller failure...scoring of roller and cam which wore away the hardened surfaces and destroyed both.

Upon inspection and tear down I started talking to local Dodge techs, as well as some online and even as far as discussing it with some builders at petty enterprises. From there I talked to a local shop who builds LS engines for the Chevy guys...and guess what....the GM DOD system...fails exactly the same way.

My conclusion: They will eventually fail, whether it is at 10K or 200K eventually something breaks down...whether the oil restriction....blockages...surface wear, who knows. I chose to eliminate it all together, no more solenoids, no more restrictors, eliminated it with a tuner, put in some non MDS lifters and heavy duty pushrods.

The dealer techs say that the cop cars fail from idling constantly...followed by the SRT cars...but much less on the 6.4s than 5.7 failures.

the concept is sound...but anytime you have rotation and metal on metal....limiting oil flow is not the answer.

that is my 2 cents, I am in the process of mounting my wiped cam and lifter on a plaque to remind me of this...for my office.

Luckly I was able to do all this work myself jsut having to pay for parts, I feel for the guys out there who woudl have to out of pocket this...or worse yet keep driving it until it gets enough trash it wipes out the engine all together.

PS: all oil changes pre-me were dealer at scheduled intervals, mine are all by me with Liquimoly 0W40 at slightly less mileage than scheduled, with one oil analysis per year.

 

[Ronmc1]

i used to think "No MDS is a tried and trusted system" but since my failure 2 months ago, and research associated with it I have come to think that it is indeed an issue, not just for Chrysler but across each platform that uses a similar method of oil restriction/lifter deactivation.

Mine is a 126000 mile 2011 SRT8 Challenger that had a catastrophic failure on an MDS lifter, wiping out not only the lifter but the cam. Upon tear down (all done by myself) it was evident that the lifter/roller had experienced restricted oil flow leading to roller failure...scoring of roller and cam which wore away the hardened surfaces and destroyed both.

Upon inspection and tear down I started talking to local Dodge techs, as well as some online and even as far as discussing it with some builders at petty enterprises. From there I talked to a local shop who builds LS engines for the Chevy guys...and guess what....the GM DOD system...fails exactly the same way.

My conclusion: They will eventually fail, whether it is at 10K or 200K eventually something breaks down...whether the oil restriction....blockages...surface wear, who knows. I chose to eliminate it all together, no more solenoids, no more restrictors, eliminated it with a tuner, put in some non MDS lifters and heavy duty pushrods.

The dealer techs say that the cop cars fail from idling constantly...followed by the SRT cars...but much less on the 6.4s than 5.7 failures.

the concept is sound...but anytime you have rotation and metal on metal....limiting oil flow is not the answer.

that is my 2 cents, I am in the process of mounting my wiped cam and lifter on a plaque to remind me of this...for my office.

Luckly I was able to do all this work myself jsut having to pay for parts, I feel for the guys out there who woudl have to out of pocket this...or worse yet keep driving it until it gets enough trash it wipes out the engine all together.

PS: all oil changes pre-me were dealer at scheduled intervals, mine are all by me with Liquimoly 0W40 at slightly less mileage than scheduled, with one oil analysis per year.

With 126,000 miles a failure in the MSD system is not surprising. I will remove my MSD system when I reach that level of mileage if something else doesn't go first. I don't think a lot of owners are driving this type of car around on 4 cylinders willingly?

 

[Smokn05]

Great info, thanks. I wonder if MDS failures are related to the amount of time spent driving with MDS active or if the MDS lifters will fail even if they don't spend a lot of time collapsed for MDS mode. Kinda makes me want to drive in Sport mode and not even use MDS anymore. I'll certainly do factory oil changes or maybe slightly sooner.

Maybe I'll see if I can make it to 75k miles using good oil and changing it often and then once I'm out of warranty change the cam/lifters to eliminate MDS. I sure like the sound of a 274 cam at idle anyway so that would make a good excuse to swap cams. lol

 

[Smokn05]

With 126,000 miles a failure in the MSD system is not surprising. I will remove my MSD system when I reach that level of mileage if something else doesn't go first. I don't think a lot of owners are driving this type of car around on 4 cylinders willingly?

Lol, I'm one of those owners. :grin2: I drive 100+ miles a day for work and take road trips a lot. I put 7,000 miles on my car in the first 35 days. So unless I am purposely trying to use that sweet Mopar power for enjoyment, I do try to get the best mileage I can on the highway. The way I look at it is, I could drive my wife's Dart and get 45mpg and save a lot of money on fuel but where's the fun in that? I want to enjoy my commute so by having lots of power available, I can use it as needed to put a smile on my face yet still get the best economy I can for the vehicle.

Some days I smile more than others. Those days are expensive. :grin2:

 

[Ronmc1]

Lol, I'm one of those owners. :grin2: I drive 100+ miles a day for work and take road trips a lot. I put 7,000 miles on my car in the first 35 days. So unless I am purposely trying to use that sweet Mopar power for enjoyment, I do try to get the best mileage I can on the highway. The way I look at it is, I could drive my wife's Dart and get 45mpg and save a lot of money on fuel but where's the fun in that? I want to enjoy my commute so by having lots of power available, I can use it as needed to put a smile on my face yet still get the best economy I can for the vehicle.

Some days I smile more than others. Those days are expensive. :grin2:

With that kind of mileage you are really enjoying your car. I have a 2015 dart for a everyday driver it keeps me out of trouble. I don't have the self control to drive the challenger everyday. I would be out of tires and a license quick if I was using it for the work commute.

 

[BenchMarkVII]

126K is not a lot of miles in this day and age, i woudl expect an engine to go well over 200k without a failure of this magnitude. My last car was a 250K subaru WRX that was still on it's stock engine, before that a 200K crown vic, all sold without ever haveing had heads off (I will admit valve covers 2x on the WRX and a intake manifold on the Ford)

but a lifter and cam failure at 126K after a life of synthetic oil and regular changes, with to my knowledge never having had a track day?

Co-workers wife's G8...DOD failure at 49,000 took out cam...

 

[sctm81]

i used to think "No MDS is a tried and trusted system" but since my failure 2 months ago, and research associated with it I have come to think that it is indeed an issue, not just for Chrysler but across each platform that uses a similar method of oil restriction/lifter deactivation.

Mine is a 126000 mile 2011 SRT8 Challenger that had a catastrophic failure on an MDS lifter, wiping out not only the lifter but the cam. Upon tear down (all done by myself) it was evident that the lifter/roller had experienced restricted oil flow leading to roller failure...scoring of roller and cam which wore away the hardened surfaces and destroyed both.

Upon inspection and tear down I started talking to local Dodge techs, as well as some online and even as far as discussing it with some builders at petty enterprises. From there I talked to a local shop who builds LS engines for the Chevy guys...and guess what....the GM DOD system...fails exactly the same way.

My conclusion: They will eventually fail, whether it is at 10K or 200K eventually something breaks down...whether the oil restriction....blockages...surface wear, who knows. I chose to eliminate it all together, no more solenoids, no more restrictors, eliminated it with a tuner, put in some non MDS lifters and heavy duty pushrods.

The dealer techs say that the cop cars fail from idling constantly...followed by the SRT cars...but much less on the 6.4s than 5.7 failures.

the concept is sound...but anytime you have rotation and metal on metal....limiting oil flow is not the answer.

that is my 2 cents, I am in the process of mounting my wiped cam and lifter on a plaque to remind me of this...for my office.

Luckly I was able to do all this work myself jsut having to pay for parts, I feel for the guys out there who woudl have to out of pocket this...or worse yet keep driving it until it gets enough trash it wipes out the engine all together.

PS: all oil changes pre-me were dealer at scheduled intervals, mine are all by me with Liquimoly 0W40 at slightly less mileage than scheduled, with one oil analysis per year.

If you do even more research you'll also find out that a lot people who experienced the lifter/cam failure on HEMIs had them failing on non-MDS lifters just as much, so it might very well be related to the quality/design of the lifters and not the MDS specifically.

It's a real shame that you can spend easily $50k on this car and after only 60k miles the manufacturer can't guarantee this thing to work flawlessly if properly maintained and won't take responsibility for anything.

From what people say this is a 5-7k repair bill. Heartbreaking.

Here is a really long thread from the RAM forums that deals with this issue.

https://www.ram******.com/archive/index.php/t-188978-p-3.html

 

[BenchMarkVII]

From the guys I spoke to, it was mostly MDS engines that had the lifter failure. When I was looking at the cars/failures it was always the MDS lifters, not the non MDS ones that was directly next to it.


I will say, any manufacturer can and does have failures, I have had Ford intake manifolds fail, Subaru fuel lines fail, Toyota crack main bearings.

to repair it just in parts was close to 2k if not a tad more when taking into account fluids, and filters and such
the hassle was more in diagnosis, and teardown that was required to see what it was going to take to actually properly repair the issue.

 

[deano379]

The MDS on my 2011 SRT does not engage at highway speeds, only in the 40/55 MPH range. Lower MPH if under light throttle, like going downhill.

So, don't expect better highway mileage, at least not if you drive at 65 or higher.

I deactivated MDS and don't miss it.

 

[sctm81]

From the guys I spoke to, it was mostly MDS engines that had the lifter failure. When I was looking at the cars/failures it was always the MDS lifters, not the non MDS ones that was directly next to it.


I will say, any manufacturer can and does have failures, I have had Ford intake manifolds fail, Subaru fuel lines fail, Toyota crack main bearings.

to repair it just in parts was close to 2k if not a tad more when taking into account fluids, and filters and such
the hassle was more in diagnosis, and teardown that was required to see what it was going to take to actually properly repair the issue.

The RAM thread I linked shows plenty of non MDS lifter failures. Overall there are more MDS engines than non out there (automatic vs manuals. More Chrysler 300s, Chargers, Durangos, Jeeps, RAMs,etc compared to manual Challengers) so statistically you should see more MDS engines fail. But that does not necessarily make it the cause of the problem.

 

[GreeninTN]

it blows my mind that a modern roller cam motor would even eat a lifter but they do.

Alot of those FB threads I ask about MDS usage/ oil type etc but you never get a straight answer so no way to get any kind of data.

The ones that I see where the lifter is side ways I suspect is over rev bent push rod but again when I ask if the rev limit is messed with there a rant about how bad FCAU cars are etc. People dont own up to anything these days.

When I was younger I could tear a car up easy in less than a year now my last Honda as 335k miles all on 10w40 oil and 150 or more runs on the Dragon with no windage tray and redline everytime I drive it. My 77 Chrysler is pushing 140k. Flat tappet cam and again modern 10w40 oil that your not supposed to use.

I just dont jump on a car until its warmed up and I always let a car run 2-3 mins to get the oil moving.

 

[Profd2]

Had MDS lifter failure on 2013 Challenger R/T 5.7. 50,000 miles at time of failure. Oil changed regularly at the dealership. Often I changed the oil at 1500 miles because of winter storage... just wanted fresh oil in the spring. Car is at dealership waiting on back ordered lifters now, it is under extended warranty. The sound of a failed MDS lifter is very annoying. Noise is very noticeable at low speeds while decelerating. Sounds like a playing card in a bycical spoke. If you here this switch to paddle shifting... if the noise stops, you have a lifter failure. I'm glad I got the extended warranty but with no parts to fix it I'm afraid her driving days will be over until next spring. I hope this helps answer any questions people might have.

 

[Solidman]

Slack in metal is not good for the long run especially in a vertical motion. I always run mine in Sport mode, and I change mine at 5k or sometimes earlier since I am retired. Highway miles are the best miles in terms of wear and oil cleanliness.....so 3K oil changes are not needed. Staying with the Factory oil is the perfect choice for the 392.

 

[Hal H]

the 5.7 and 6.4 engines utilize the same lifters whether its the

M6 application (no MDS)
A5 / A8 application (w/ MDS)

for the respective part # called for

its the roller needle bearings that simply wear out. Considering how small they are and the millions of revolutions those bearings go through in 150 - 200k, they're going to wear.

Like @Profd2 mentioned, if there's an unusual noise - be proactive and investigate!
-its cheaper to tear down, remove heads and replace the lifters & cam before it gets worse.

Ignoring something to see if it goes away is only going to become a more costly repair or a catastrophic repair.

There's millions of 5.7s rolling around with MDS since it appeared on MY 2006.

The police cars are probably more severe examples - as it may have so many miles on the ODO, but there's thousands of hours of idling time which some formulas say take engine hours x 60 = miles equivalent.

I'd suspect most departments run conventional oil in their 5.7s (that's what's called for) and whether they're buying bulk oil at lowest bid prices vs. premium brands or full synthetic. Its all about fleet operating costs - fuel, tires and overall maintenance factor into how its approached.

Most departments probably retire patrol cars at set intervals or scrap them if involved in collisions - its another piece of equipment that gets replaced...

I see some small towns around where I live and some departments still have Crown Vics rolling around, despite the MY 2011 was final year, so the newest ones would be coming up on ten years old now - but don't get the high miles due to patrolling a smaller area vs. a larger city.

 

[Rockster]

the 5.7 and 6.4 engines utilize the same lifters whether its the



for the respective part # called for

its the roller needle bearings that simply wear out. Considering how small they are and the millions of revolutions those bearings go through in 150 - 200k, they're going to wear.

Like @Profd2 mentioned, if there's an unusual noise - be proactive and investigate!
-its cheaper to tear down, remove heads and replace the lifters & cam before it gets worse.

Ignoring something to see if it goes away is only going to become a more costly repair or a catastrophic repair.

There's millions of 5.7s rolling around with MDS since it appeared on MY 2006.

The police cars are probably more severe examples - as it may have so many miles on the ODO, but there's thousands of hours of idling time which some formulas say take engine hours x 60 = miles equivalent.

I'd suspect most departments run conventional oil in their 5.7s (that's what's called for) and whether they're buying bulk oil at lowest bid prices vs. premium brands or full synthetic. Its all about fleet operating costs - fuel, tires and overall maintenance factor into how its approached.

Most departments probably retire patrol cars at set intervals or scrap them if involved in collisions - its another piece of equipment that gets replaced...

I see some small towns around where I live and some departments still have Crown Vics rolling around, despite the MY 2011 was final year, so the newest ones would be coming up on ten years old now - but don't get the high miles due to patrolling a smaller area vs. a larger city.

Some years ago I was involved in a vehicle trip recorder/data logger product and one targeted specifically for fleet operators. Tech support got more than a few calls regarding "idle time" which the device recorded. The operators were quite surprised by the big idle time numbers believing the numbers to be wrong. They weren't. Fleet vehicles spend an inordinate amount of time idling. Even privately owned passenger cars idle more than one might think.

Years ago when Porsche moved from mechanical lash hardware to hydraulic lash hardware (aka hydraulic lifters) it was concerned about particulate matter small enough to pass through the regular oil filter but large enough to cause problems with the hydraulic zero lash hardware. This mechanism relied up extremely tight sliding fits to work. Among other things the tight fit to help act as a "seal" to keep the oil under pressure from bleeding out of the adjuster as the cam lobe pressed down on the lifter as it opened the valve.

Porsche fitted a bypass filter with a much finer filtering medium. As a bypass filter it didn't get all oil routed to it -- unlike the regular filter -- but just some. The idea was this bypass filter would remove the finer particles and prevent any issues with the new hydraulic lifters. But over not much time Porsche found the bypass filter unnecessary and eliminated it.

But I wonder if perhaps a bypass filter might be called for with engines with roller lifters with the very small and heavily loaded needle bearings?