MDS question

[scott lass 18]

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.

me too amsiol baby mine 59000 i do oil 2,000 or 2600 miles hoping to get 200,000 off truck ! been working on cars 70 s building race type for street as a kid ! camry 1888 mile on it mobile one no engine problem just spark plugs ! I feel like many sure bad lifters but turning a motor off and on even only 4 would cause problems and other like chevy mds ya burning up now ! thing is mine going in a lifter I bet conpression low so we will see ! I could cry work so hard to keep truck like new !

 

[Harley Harrold]

I purchased my 07' Quad Cab 1500, rwd, 5.7L Hemi in Dec. 2013 with less than 58K miles on the odometer. In 2014 I loaded a performance tune on my truck that I made adjustments to the tune including turning off the MDS. I didn't see much in fuel mileage changes so I left it off. I now have over 89K miles on my truck. When I get ready to install a performance cam I will also replace all of the lifters and install a MDS delete engine kit.

 

[Floyd1979]

My 2009 Dodge Ram crewcab Rambox hemi MDS failed around 325,000
While repairing that, they noticed cam and lifters worn on certain cylinders. they replaced the cam and lifters under the lifetime power train warranty.

Always did oil changes , right motor oil .

 

[boblonben]

14 and up, run with no MDS. If and when you rebuild the engine, remove it entirely and go with better lifters.
Been reading this stuff for last 5 years, had lifter failure and cam replaced under warranty, always ran PUP regular oil change ntervals and still had the issue, truck hardly ever idles and I drive 189 miles to work so short drives are not an issue.

DIsengaging MDS IS the only thing I did not practice.,
I Do now.

why?? disengaging does you NO good in the long run. But am sure you have 'better' ideas. Yepper...

 

[boblonben]

I purchased my 07' Quad Cab 1500, rwd, 5.7L Hemi in Dec. 2013 with less than 58K miles on the odometer. In 2014 I loaded a performance tune on my truck that I made adjustments to the tune including turning off the MDS. I didn't see much in fuel mileage changes so I left it off. I now have over 89K miles on my truck. When I get ready to install a performance cam I will also replace all of the lifters and install a MDS delete engine kit.

if you saw no mileage difference then you run it so hard it does not engage, so wouldn't make a difference for you anyway, just ruin the engine earlier.

 

[boblonben]

I would always run with it off. If you want to prevent something from wearing out and causing issues don't use it. Not saying it won't go bad anyways but it's more prevention than running it. Just my 2 cents tho. I had mine off with the tuner and the lifter still failed so its basically roulette. I'm also a spaz about maintenance so it's not from lack of in my case.

all you are doing is wearing the MDS valve train the same, since they are NOT engaged. with MDS they would be doing NOTHING to wear on. But hey suit yourself.

 

[OCDTech]

^^^^^Troll Alert^^^^^

 

[boblonben]

these threads always amaze me as to the false info so many people lay out there, and often contradict themselves while doing so. This anti-MDS just shows one how unknowledgeable le people can make such incorrect assumptions on things and then pretend to be some kind of authority on the subject. Glad they do not drive our tanks, launch our missiles, fly our planes, or g anything important for this nation and its people.

 

[Brandon-w]

these threads always amaze me as to the false info so many people lay out there, and often contradict themselves while doing so. This anti-MDS just shows one how unknowledgeable le people can make such incorrect assumptions on things and then pretend to be some kind of authority on the subject. Glad they do not drive our tanks, launch our missiles, fly our planes, or g anything important for this nation and its people.

Please enlighten us to exactly how YOU think it works because as of now you are just full of comments not information so if we're all misinforming everyone set us straight as per this moment you got nothin....

 

[OCDTech]

 

[scott lass 18]

6 speed, dropped the pan and did fluid and filters at 120k (I'm following the service manual to the letter to see what happens). Fluid was still red, nothing weird to report. Refilled, nothing changed still shifts like the day it rolled off the lot.
Did the transfer case at the same time, fluid looked like the new fluid.
I've done both diffs 3 times, rear looked new every time. First change on the rear I pulled the cover to look for flakes and there weren't any. Front was a little darker than new on first change.
Oil has always been conventional, changed every 5k, always comes out looking the same as the new. No oil consumption at all.
Flushed coolant at 150k.

Literally the only problem I have other than the manifold bolt being broken is my AC doesn't work. I have a leak somewhere and the refrigerant is dealer only, was quoted some crazy high number like $2k to fix it. So I just bought window vent guards and leave my windows cracked all summer. Oh and I've done 3 CV axles in the past 3 years.

for your A.C. get a glow pin at auto zone did mine at night and saw some glow in back of pump but not at connection to it every two years do a little charge ! dealer says it runs normal ya right not ! added almost a can in it still leaking some were don't know ? but this way u can fine cheap shop to fixt and know what it it !

 

[scott lass 18]

Hey Scott. Is it ticking? Mine would tick slightly at start and then once warm 1/2 hr worth of running you could hear it clacking lightly. Then I got the dreaded misfire code and I knew. I'd start with a compression test. It's cheap and really shows you the condition of your engine determining weather you go foreward looking or just straight up replace/rebuild. Then I'd check plugs and maybe try replacing the coil. Cheapest things first. Replace the two plugs on #1 cylinder where u getting misfire and maybe try swapping coils and see if the misfire moves and go from there.

so replace new plugs now code goes off each morning did coil no luck so have shop do compression test so if presser doesn't go high this be like a lifter next right ! engine like new 59,000 so pressure should be around 140 ? or would presser go higher ?

 

[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.

so is it mds on 5.7 chevy truck 2017 ? brothers truck ? doesnt take care like me does 5ooo oil change I bet !

 

[Brandon-w]

so replace new plugs now code goes off each morning did coil no luck so have shop do compression test so if presser doesn't go high this be like a lifter next right ! engine like new 59,000 so pressure should be around 140 ? or would presser go higher ?

Make sure they do a dry compression test and a wet one (oil added to cylinder) and see what the difference. If both are low it could be bad compression. If pressure is low I'd take the valve cover off and make sure there are no bent puahrods or broken valvesprings.
My truck came in at 180-185 psi across the board I only did the dry test as it was high enough. It may be a bit confusing but if it's close across the board and one is low it's likely a lifter. A good mechanic should be able to tell once into it Alittle more.

 

[Brandon-w]

so is it mds on 5.7 chevy truck 2017 ? brothers truck ? doesnt take care like me does 5ooo oil change I bet !

I Beleive mds is available on all Chevy trucks. Don't hold me to this tho been out of the Chev game for a few years now. They stopped making the 5.7 years ago though. Now it's just 4.8l 5.3l 6.0l and 6.2l v8s I Beleive. They make a 7.0 and Beleive the 8.0 is still on production too but not seen as often.

 

[RVGuy]

I Beleive mds is available on all Chevy trucks. Don't hold me to this tho been out of the Chev game for a few years now. They stopped making the 5.7 years ago though. Now it's just 4.8l 5.3l 6.0l and 6.2l v8s I Beleive. They make a 7.0 and Beleive the 8.0 is still on production too but not seen as often.

Chevy's is called AFM in the old trucks and DOD on the new ones. The old AFM was partly similar in that it shut down the same 4 cylinders each time but they engineered it into the engine different than Ram. DOD can shut off any cylinder(s) in any order, it could run on 1 cylinder if it saw fit. Chevy's AFM was prone to consuming oil for whatever reason, they had way more problems with it than with our MDS, haven't heard anything from the DOD ones yet but it's still brand new.
Chevy puts the AFM on everything. V8s, V6s, I think possibly some V4s. Their new turbo on the trucks has AFM with the turbo! They're heavy into it, turns me right off of them as you can't turn it off like ours by manually selecting the top gear. You have to select the 2nd to top gear, so 5th on the 6 speed or 7th on the 8.

I've read WAY more failures on the Chevy forums with their lifters and cams than here. I've seen people posting where they wiped out a lifter at 40 miles on the way home from buying it at dealer.

 

[Brandon-w]

Chevy's is called AFM in the old trucks and DOD on the new ones. The old AFM was partly similar in that it shut down the same 4 cylinders each time but they engineered it into the engine different than Ram. DOD can shut off any cylinder(s) in any order, it could run on 1 cylinder if it saw fit. Chevy's AFM was prone to consuming oil for whatever reason, they had way more problems with it than with our MDS, haven't heard anything from the DOD ones yet but it's still brand new.
Chevy puts the AFM on everything. V8s, V6s, I think possibly some V4s. Their new turbo on the trucks has AFM with the turbo! They're heavy into it, turns me right off of them as you can't turn it off like ours by manually selecting the top gear. You have to select the 2nd to top gear, so 5th on the 6 speed or 7th on the 8.

I've read WAY more failures on the Chevy forums with their lifters and cams than here. I've seen people posting where they wiped out a lifter at 40 miles on the way home from buying it at dealer.

Ouchie. Still proves the system is flawed no matter the application. Wonder why boat engines woyh the hemis in them don't have mds. [emoji48][emoji48] I just can't stop poking the bear. I'd be very mad if I bought a truck and it did that tho. That's some good info though thank you. [emoji106][emoji846]

 

[RVGuy]

Ouchie. Still proves the system is flawed no matter the application. Wonder why boat engines woyh the hemis in them don't have mds. [emoji48][emoji48] I just can't stop poking the bear. I'd be very mad if I bought a truck and it did that tho. That's some good info though thank you. [emoji106][emoji846]

No worries, I do a lot of reading in my spare time. The dealership I work at is closed for two weeks right now so lots of spare time!
I'm not sure if it's actually the MDS/AFM system itself that is doing things in or just the fact that they incorporate a weaker hydraulic lifter in order to use the system. Even then it's weird though because if you read through the Charger forums they have lifter failures on the non-mds cylinders.
Interestingly enough if you go back on any of the forums the problems really started the year they added VVT to the engines.

 

[Brandon-w]

No worries, I do a lot of reading in my spare time. The dealership I work at is closed for two weeks right now so lots of spare time!
I'm not sure if it's actually the MDS/AFM system itself that is doing things in or just the fact that they incorporate a weaker hydraulic lifter in order to use the system. Even then it's weird though because if you read through the Charger forums they have lifter failures on the non-mds cylinders.
Interestingly enough if you go back on any of the forums the problems really started the year they added VVT to the engines.

Something does seem off that way hey. Who do you work for? Gm dodge Ford?

 

[RVGuy]

Something does seem off that way hey. Who do you work for? Gm dodge Ford?

I'm an RV tech, so at an RV dealer.
We're a chain of dealers though in BC/Alberta so there's also a Dodge, Ford, and Subaru dealership in the company.