Is MDS Damaging Your HEMI? The Answer May Surprise You! 

Let me know if you like this sort of video, and what system would you like to see me cover next? Thank you for watching!

As a recently converted Chevy guy I'll tell you that your videos are fantastic and I've referenced them many times while repairing my 300C with a 5.7 after it dropped 2 valve seats. You're great at breaking down the system and explaining what's going with the system and why something like MDS is even there to begin with and the thinking behind the whole design. So yeah you're the best on RU-vid with these modern factory Hemi engines so keep the information coming bro and thanks for the help.

Loving these deep dives. There is a ton of misinformation out there about hemis and we don't really have many ways to prove or disprove a lot of the claims. Mad respect for you taking the time to explain all of this.

Being a 2015 Ram 5.7 owner, I appreciate every video you do on these engines!

Learned a lot from this channel. Keep all videos coming. Appreciate your time. Definitely gonna get some merch

Very excited to see your visual oil pressure system!!

this is so awesome! cant wait to see the visual oil flow system u make

Love this entire series on the dreaded hemi lifter monster! I worked at a 5 star Chrysler dealership back in 05 when they reintroduced the charger with a hemi. I saw this on so many engines during my time there and we never really got any support from dodge on it. I have a 2019 R/T with the 5.7 so I've been eager for your content regarding this. Your research has been amazing and really appreciated! Keep up the good work!

Great video, lots of info on the MDS packed into this one.

Great job explaining. I love learning the how and why about how things work. I feel like there's so much speculation in regards to the mds system and lifter failure. It's invaluable to get insight from people like you with repeated first-hand experience. Great video, love the content. Can't wait to see the oil pressure demonstration.

Brother, I think your channel is pretty good and I'm glad that there are channels like yours, I've learned a lot from your videos and I've also put into practice many of the things you've explained and taught...! good job and may you be very successful

I experienced the cam//lifter failure in my 2010 Ram 1500 in November and did the repair myself. Mine was the #5 intake that failed, which is a non-MDS lifter, so correct, the failure occurs with both MDS and Non-MDS lifters.

Yes I am a student so this format appeals to me you are clear & to the point with important information.

Great insight Sky! Lots of good information

By far the clearest and best explanation of hemi mds. Thanks for explaining it.

it was cool to see the oil gallerys thru the lifter bores. its good to get this kind of detail so i know what to expect when i build a 5.7 . Your oil testing tool will be a cool video. cant wait to see it. take it easy sir.

Another excellent educational video. Great explanation of how MDS works 👍

GREAT video thank you for explaining how this system works!! I really enjoy these videos explaining how the Hemi works keep them coming. Could you potentially do an entire oiling system review on the Hemi motor? I would love to see the entire oil path...

So far it works great in our 2019 Dodge charger. Great video with a lot of very interesting information.

I like these type of videos bro. Very informative. I talk to the homies about Hemi engines sounding like an expert. Thanks 😎

This video is a keeper! I have a 2011 RAM with the 5.7 Hemi, automatic transmission, 2WD. I really like the truck, and I am obsessed with maintenance and reliability. This information has helped me understand the MDS system and strengthens my resolve to change the oil and filter every 3K using full synthetic oil and top-tier filters. I look forward to seeing your next video. Thanks sincerely.

Awesome, I've been waiting for this one. TY!

I have always enjoyed the content that you put out, Thank you sir and I have learned so much from you. Thank you.

Thank you for pointing out the "galley/gallery" difference. I was guilty of being ignorant to this fact for many years, also. Excellent video/insight!

What an awesome explanation 👍🏻 great video bro 😎

Nice clear explanation of how the mds works, I never even thought about the need for positive cylinder pressure so the deactivated cylinders wouldn’t be trying to scavenge oil from the crankcase 🤔 Pretty cool!

I really enjoy these kinds of videos, I appreciate your time, effort and expertise that you share with us, thank you Sir 😁👍

Excellent tutorial

I love these style videos. Learning as much as I can about the engine in my truck. I went through a lifter failure recently, now I have a new engine. I don't want that happening again, and I wanna get another 200k miles outta my girl. These videos are incredibly helpful!

Brilliant video, I’ve always wondered how this system works and if it a good thing to have. You explained it very clearly. The only thing I didn’t hear you mention is how critical is it to use the correct oil for this system to work properly. Thank you for a great video. I drive a 05 Jeep Grand Cherokee with the 5.7 and love this Jeep.

I'm always looking for more useful info. Great explanation

Thanks for the video!

2017 1500 Big Horn owner. Thank you so much for explaining this. I've been manually disabling this system by using the manual gear button on the steering column every drive. Going to start letting it do its thing now. I've heard so many rumors of lifter failure due to this system, however, I am a strong believer that changing your oil on time, every time is the biggest help for any vehicle. Thanks!

Another great video!

I've seen a bunch of videos on this topic, and I will say that I truly got a better understanding of this system from this video. Thanks 👍! With that being said, I currently own a 5th Gen hemi 1500 Crew cab bighorn. This is my 3rd hemi truck. I'm not a fan of waiting 7,500 miles between oil change, so I do mine at 4,000 miles, religiously and have had no issues. 2019 currently with 57k miles. Oil change is critical for any engine to run well.

Love these walk through videos. Actually seeing the parts and how they work in detail helps tremendously because I know nothing about this stuff. I am a little confused though on one thing - if MDS is off, is there any oil making it to the lifters? A lesser amount of oil? In either case, isn’t that a bad thing? I don’t know anything about engines but you’d think less oil is bad (even if the oil pump is pumping the max amount).

I skimmed through the comments but didn't see anything related to the exhaust manifolds leaking. It is pretty coincidental that the exhaust bolts started breaking in the 4th Gen Rams when MDS was introduced. Then Ram beefed up the bolts for the 5th Gen Hemi Rams, which then only moved the problem to the manifolds cracking, which are now the week point. Many suspect that the MDS causes the exhaust temperatures from the "disabled cylinders" to be cooler than the exhaust from the "active cylinders", which causes uneven heating of the manifolds. These exhaust leaks started when MDS was introduced.

Really good video,thank you, you make a very good teacher

Awsome video my guy. 👍

In my 2022 Challenger R/T, to avoid the lifter/cam issue, I now try to keep an eye on when the engine goes below 1000 rpm. I avoid unnecessary idling (e.g., going through a drive-thru, or sitting parked with it idling to stay cool/warm). If I'm stuck in crawling traffic (which is rare), every minute or so, I rev it up to 1200-1500 and hold it there for a few seconds to "feed the lifters" the oil they need. Eventually, I'll swap out to the new higher flow Melling pump so I don't have to worry about it.

Great explanation of the system. I am one of the people who have seen 23 - 24 mpg in my 08 Charger with the cruise set at 80mph on the interstate between Idaho Falls and Boise on more than one trip. We could see 16 - 17 mpg around town if we keep the road rage under control. In my RAM, especially the 10 model, it didn't do much once you get above 50 - 55. Throttle position is one of the factors for activation, and the trucks are heavy and requires more throttle at higher speed to maintain which puts it out of range. Love your videos, keep up the great informative content!

👍 very helpful. Thanks for sharing.

That was very informative, thank you once again, your videos are awesome 👍😎.

Great Video !

This was a fantastic video. I am new Ram 1500 owner. 2016

Thanks for another amazing video! These deep dives into how the various systems work are fantastic. I have a '17 Cahallenger Scat 6.4 manual, and just bought a '23 Ram 5.7 (gets delivered tomorrow, pretty pumped, first NEW truck) anyway, saw a video on another channel about the tick and oil viscosity. Poster claimed dodge changed the recommended oil at some point to a lower viscosity, and that going back to 5w30 from (i think) he said 0w20, fixed his tick. Did dodge change viscosity recomendations at some point? And whats your take on this? Thanks, and keep it up!

Great info Thanks!

Very good explanation of mds system. I hope you can show a video of using a tuner to deactivate the mds.

Great advice by not idling. I'd take it a step further and run 5w30 synthetic preferably redline or PUP

Sky, can you cover the 8HP70 transmissions, in particular the difference when running in Sport Mode via button, versus the ‘S’ position on the shifter knob? Seen many of your MDS videos, and by far appreciated explaining how not all HEMI’s come with it. Thank you!

Great video... info.

Very interesting, thank you

Great work man, keep it up! Can you do a video on replacing the power steering pump on a 06-10 Charger? Or if you've done one already link it for me!?

I have to say the 6.4l HEMI has been very good for our company and we work the dog shit out of them hauling 400 gallons of water in the bed driving all over the place on Oil Lease roads 12-14 hour days 5 days a week with lots of idling time. I stayed with 0W-40W Mobile 1 and currently sitting at 175k miles on a 2018 only problems we had were a fuel pump failure at 68k and a Radiator failure at 167k miles. I still do not hear any sounds of the Lifter roller failure yet. Out of our fleet of trucks we have lost 2 engines one to the lifter cam failure, but that truck was not serviced as it should have been and failed at 150k miles. To me the the 150k mile mark has been worth the engine performance we have gotten out of it. Had it been properly serviced like I have done to mine I believe they would make 200k. I am fixing to move into my new 2024 with a 6.4l work truck and will update it through its life time. I have learned a few things since that time from this channel that I will be doing with my new truck. Through its flaws I still think the 6.4l Hemi has been a damn good engine.

One of the best vids I've seen about the cam issue. I have a 6.4 scat and it had the cam problem. I will agree the car is not made to idle. It's a design flaw in the block. If you commute in a car like this sitting in rush hour traffic then you will have the cam problem. You say the MDS is well thought out. I don't agree. It's an inefficient add on because of cafe standards. With my car MDS is off in sport mode and I purchased a tuner to turn off MDS in regular drive mode. It's been 4 years since the cam was replaced and it runs like a top. The MDS would come on in 3rd gear, the motor/exhaust had a weird drone and you have to punch the gas pedal to get out of it. I get 1 to 2 mpg better on highway without MDS. It cost 6 grand to replace the cam then. I can only image what it costs today.

Great content thanks

Awesome video

Great Video

Thank you!!

When we first bought ours I hit 30 mpg at highway speed (cruise set at 65). Sweet!

Awesome awesome awesome video!

I've had my 2015 5.7 Ram since new and continue to have zero of the problems people warn about on these engines. MDS is a great way to maintain dynamic compression under light throttle without EGR & with a single camshaft. The dudes who always complain about MDS are like the old guys 40 years ago who didn't want to let go of carburetors and distributors.

Thank you

WELL DONE. Thank you 🇺🇸🇺🇸🇺🇸🇺🇸

Cooling system upgrades. 180 degree thermostat, larger radiator. Transmission cooler. Things to keep the engi e cooler and in the performance band in the South during summer. We don't really have a winter.

Thanks. Having some relation to ECM tuning, I can't even count how many times I've been hearing that sad-sad story about the MDS killing the engine. No, sir, It's absolutely not you using cheap engine oil and extending the oil change intervals, it's the dumb MDS. But here finally is a video that I can share, just to explain the whole thing. Thanks again! My 2c - I personally think that what could really improve MDS operation is increasing the torque output of the engine. We're talking about N/A street daily driver engines, so no forced induction here - but a good AFR in all modes and some nice and smooth spark maps with more advance definitely help. Factory Ram tune is quite conservative to make it operable on low-octane fuel, but if the owner is ready to forget about the low-octane forever - then we can get more torque and efficiency out of the engine without sacrificing the mileage or the lifetime. And it would work for both V8 and V4 modes. Sadly, the well-known calibration editor for Dodge kind of lacks in terms of accesible MDS-related parameters. I've seen and experienced the same effect on GM trucks, 3rd gen Tahoes and Escalades mostly. Proper tune for a stock engine is a world of difference, and the AFM/DoD, which is GM's name for variable displacement system, really helps save some fuel on the long highway trips and moderate throttle city drives. Anyway, this has been a great video and definitely looking forward to the actual work demonstration that you've mentioned. Keep up this awesome channel!

@ReignitedAuto Always enjoy your tech talks. Look forward to an instrumented oil system test - would be VERY interested to know where the pressure drops (restrictions) are within the oil system of an Eagle engine. Also curious, just to cover the upgraded oil pump - what is the pressure rating of a factory oil filter (very thin, stamped and rolled 28ga? sheet metal)?

Very good video. Thanks so much for the educational content. Could you do a video on why you think the 5.7 and 6.2 Hemi’s seem to be prone to dropping valve seats? GM also has an issue with that on their 6.2 V8’s. I would love to hear your take on that issue.

Great video as always and thanks for the in depth information. But - wen you say that a person gets in their car and turns the MDS off, is that meaning using the +/- switch on the shift lever (if they still have one)? Which causes the ECO to stop displaying, and the current highest gear to be displayed. Also, I notice that the ECO (MDS?) does not come on when in Tow/Haul mode. Does this mean when in Tow/Haul mode that the MDS lifters are not getting the oil that they should either?

Great video, do you think the changes in 2022 Ram made to a thinner oil is to help prevent the lifter failure? Or is it just to chase better mpg?

I turned off the MDS in our '14 300C 5.7 hemi about 4 years ago, using my tuner tool along with loading a hotter tune in the ECM, car returns 21-24 mpg with all 8 cylinders firing while driving at highway speeds. Works for me, have the option to turn it back on if I sell the car in the future. Mileage with MDS on was about the same, but the noise from it operating was enough to drive a person nuts, thus, good reason to turn it off IMHO. I also run a factory stock exhaust off my 6-speed Challenger, so resonance will be different in that exhaust, and it has 2.5" tubing as opposed to 2.25" stock system. I keep oil & filter changed with good synthetic oil at or around 4K miles, no crud or sludge deposits inside this engine at all. Great tutorial on this system, thanks Skye!

Great video. What do you think about people switching the engine oil weight to 5w30 ? Thanks.

2015 Ram short box/ reg cab. Hemi with no issues at 195,000 kms. Do my own synthetic oil changes. Best highway run last summer pulled 25 mpg, pretty good. Truck has catch can and muffler delete, MDS not a problem or issue for me.

Good morning, first I love your videos and thank you for educating me. I am no technician, however, your videos has given me the courage to perform tasks on my 2019 dodge charger. One question, can the cam be damaged and the lifters are not? I am getting misfiring in 3 and 5. Dodge techs could not find out what the problem is. Everything is new to the pistons. Please help. Thnx!

Your the hemi goat

Man I really liked your videos early on. You were doing mods and swaps and kept every step clearly laid out and in reach for us weekend mechanics . Now anytime I try to get any random help with my ram all I see is your latest “hemi tic” video or some other version of another video you’ve already made a year or 4 back that obviously did well for you. So well that it seems you’ve chosen your audience based on the views. Add dramatic title to already dramatic situation and that equals views from those desperate individuals with hemi tic issues or MDS concerns. I don’t blame you if it’s paying the bills. Hot issues like that have that potential. I’m just saying I enjoyed your c10 content and the different hemi builds. And personally I can’t get far enough away from this hemi tic bs. It’s old news. Id think by now we know the cause, repair, and preventative fix. And in my case thanks to you for much of that. I feel your initial work on these old topics years back were plenty informative and are still available. Take care

It's wild to see how complex these systems are. It boggles my mind how the engineers over decades could figure this out.

💢 Plastic Lifter Trays, allowing lifter rollers to rotate few degrees off axis to cam? Creates a skid effect over time. Then eats needle bearings, then wipes cam. 2017 & Up size of the needle bearings was increased in the lifter rollers.

Hello i would like more information on the impact of the hv melling pump on the low end of the variable cam time. Like does it make it only benefit the high end? Thanks for all your in depth information. I think you and vertical visions are doing gods work for the rams. Also I have a 2016 ram I get 16 city and 21 highway on the 5.7

2007 309C 5.7l. I go 65 to 80 on highway and I average 20-24 mpg. As long as I'm steady going and not in stop in go traffic.

It’d be awesome if you explained this system for the 4.7L v8 lineup chrysler had. Owning a ram 4.7 saw I had the “eco” mode too

Id love to also see videos on crysler transmissions that are put on 5.7 hemis

Awesome

I just bought a used 2016 Ram with 113k miles runs great it's in excellent condition i knew nothing about this mds or cam issue first time owning a Dodge always been a Ford owner. I noticed it has the cold start tick and goes away after about 30 seconds warming up. I ran it with the mds off for about 500 highway miles and noticed that it had a much weaker start like it wouldn't fire up as strong so then i watched this video thinking maybe not running the mds the way it's intended is not a good idea you explained that very well i appreciate it. I was getting about 17mpg with mds off and now 18 with mds eco mode active. It starts up much stronger too the way it should.

Before watching I will say “No” MDS does not damage your engine! Looking forward to seeing what you have to say on it though

So as a “poor man’s” mds delete, is it bad for the engine/lifters if we just drive exclusively with manual mode on the auto-stick? I’m not a fan of the factory shift logic and prefer shifting myself anyway. I am wondering if this is somehow bad for the lifters never collapsing for 4 cylinder mode? Any thoughts, please? Thanks for the amazing content!

Great video, clear explanation, you know your stuff. I have the MDS on my 2015 300C and I love it. I am a conservative driver and when I take my car on the road I can get between 27 and 30 mpg. You said you have not seen numbers like 24 mpg before. Am I not to believe my trip summary?

I am curious that if the MDS system improves lubrication and good that it remain on, why does the Tow/Haul setting prevent MDS operation? You would think that at a time when the engine needs the most lubrication, that it should remain functioning? Many times when steady cruising on the highway that MDS can turn on while towing but won't due to being in Tow/Haul mode.

Hi great explanation, I’ve got a question i have a 14 charger 392 fully build engine high compression N/A and now my main problem is will the 5 speed transmission could handle the power that is producing or I’m going to face a slip in it and I thought of lot of modifications on it like upgrading the valve body and the converter but I’m worried that it won’t help Specially that the car is producing more over 600 whp I’ll be glad to hear a solution from you.

Do you have a video on installing the high volume oil pump for the Hemi?

in my case, it was a non-MDS lifter that failed, on cylinder number 5. Mine was due to previous owners who should have earned the car a salvage title who never ever did maintenance work on the car. When I changed the oil filter, it was 2 years old.

Hello, how are you? Excellent video, I want to ask you, I have a Dodge Ram 1500... year 2014, 5.7 hemi engine, it has bad lifters and apparently also the camshaft, what replacement brand can I buy other than Mopar? Is it true that if you don't put Mopar it will sound the same?

Thanks for your videos , i recently purchased a 16 Scatpack 392 and only run the car in Sport or track mode to avoid Eco mode so i guess i am possibly doing more harm than good ?? What oil pump upgrade would you reccomend? Thanks again

just wondering if you could cover the alternator and charging system .is it true that in the case of an alternator failure do you have to replace the alternator,battery and ecu ? and is there anything that can be done to avoid the alternator failure ?

I left MDS solenoids installed and plugged in with Big Cam/heads/VVT limited and non-MDS lifters. Not necessary to remove and plug, in fact it’ll limit corrosion on the receptacles. 😊 obviously the tune is the dictator

Hello Sky! Since I start watching RU-vid, try to find information who fits my problem on, 2014, Ram 1500 5.7 Hemi! Lifter failure, and cam! Maybe this cause of forget to shut off my engine for several hours! Anyhow, rebuilt my engine. this time decide to cancel MDS. and Parts has been purchased from Comp Cams performance, and MMX Modern Muscle Xtreme. here are the upgrade parts: (-NSR Stage 1 HRT 216/222 Hydraulic Roller Cam for Dodge 5.7L HEMI w/ VVT 2009+ Part# 201-300-17 -Chrysler HEMI Phaser Limiter Kit Part# 5761CPG -Evolution OE-Style No Link Bar Hydraulic Roller Lifters w/Yokes for Dodge Gen III HEMI 5.7L/6.1L/6.2L/6.4L Engins- Set of 16 Part# 85601Y-16 system. MPVI2 HEMI Engine Tuner by HP Tuners with 2 points - NEW Hellcat Oil Pump (Fits all VVT engines) Using HP tuner tool. Driving the brand new engine follow the breaking step. since everything runs fine (accumulating around 500 miles so far) except one think check engine light still coming back. Giving me this code. P000B SES, Pending, Current, Permanent Exhaust (B) Camshaft Position Slow Response Bank1. This Pinpointing the VVT technology system and my case: Phaser Limiter Kit I use to change the angle. So question? I don’t know how to rewrite my ECM to be able to turn that check engine light off? Help! I appreciate and enjoying your hard work you put in and everything you do to Mopar Chrysler owners my appreciation, Daniel.

How about those of us that want to keep the MDS working, but still want a bit more cam for some power gains? Any options there, or are we basically stuck in an "either/or" type situation.

Also could you use a hellcat piston in a truck 6.4 engine for boosted applications

I've got a 2017 Ram 1500 std cab 4x4 with the 5.7 hemi I get 22-23MPG's on the hwy if I set the cruise at or around 65. 70+ it drops to 20-21.

Hi, this video is very helpful thanks. I have a 2006 Magnum 5.7l and turned off mds without installing hardware, my block now has a hole in it LOL. I have a brand new engine being put in this week, can I get away with just non MDS lifters and the solenoid plugs, or do I need to add a camshaft to the build as well? Thanks in advance.