For the guys who think deactivating the mds via a tune is a good idea

[La Ramie]

Watch Reignited's video,it explains it even better then MMX's article does Mike. Common sense would tell you,that shutting off oil flow to the lifter bores isn't doing the lifters any good.The little bit of oil that does make it past the lifter and it's bore,and hopefully onto the cam lobe is going to be diminished.Remember the engine is only designed to run long enough to make it past the warrenty,after that the manufacture doesn't really care about the consumer.You'll also notice they used to have 100,000 mile warrenty,now its down to a 60,000 mile warrenty on the trucks.So instead of fixing known issues,they decided to drop the warrenty milege,and pass the buck onto the consumer. I have no skin in this game,all i'm trying to do is point out the obvious to alot of guys who'd never considered how the mds affects the oil flow path inside the hemi. My truck has been properly deleted,but my 2 cars that still have their original cams/lifters,still employ mds,and i could easily deactivate it on on both if i wanted,but that's not going to happen as long as i own them,or they still have their stock cams. I don't leave it activated for milege,i leave it activated for oil flow to the outside of the lifter,as lifter bore scoring is not something i'm interested in dealing with,and the fact there is going to be more flow past the lifter is not a bad thing.I also don't subscribe to the theory mds causes more wear on the engine,as that ones a myth and nobody has ever proven there's any more wear on the cylinders or bearings with or with-out mds. If you prefer to defeat mds everytime you drive the truck,that's your call,but at least you'll have learned a bit more about how the oil path operates in a Hemi

But isn’t turning the MDS off via a tune is similar to having the engine not running in MDS whether it is a manual shift selection or speeding outside of the

 

[Wild one]

So tuning the MDS off with the MDS lifter is a recipe for failure .

I don't know if i'd say its a recipe for failure,as lots of guys do defeat it,and make lots of miles with it defeated,but it's definitely not the right way to delete it.
As evidenced by this thread,there are quite a few guys who are defeating it with the +/- buttons on the steering wheel,and haven't seen any issues.
I think a bigger recipe for failure is not staying on top of your oil change intervals,and using a good quality oil filter,and long idle times.
There is a caveat though,as i don't know of anybody who's deleted it via just a tune or using the steering wheel buttons,and made a 100,000+ miles,with-out a lifter failure.
I'm hoping somebody who has made it over a 100,000 miles with MDS deleted via a tune,and hasn't had a lifter failure,will post.
Im curious if anybody has turned it off via a tune at say 60 or 70,000 miles and then made it to 160,000+ miles with it just defeated via a tune

 

[duckman631]

Still trying to understand this better. So what I’m hearing is if you leave mds on, the 4 lifters get the lube that they need cause they are closed. If you turn it off they don’t. So are the 4 that stay open when mds is on not getting lubed ever? And if they are getting lubed, how come when the other 4 are open (mds off) they aren’t getting lubed?

 

[ramffml]

I don't know if i'd say its a recipe for failure,as lots of guys do defeat it,and make lots of miles with it defeated,but it's definitely not the right way to delete it.
As evidenced by this thread,there are quite a few guys who are defeating it with the +/- buttons on the steering wheel,and haven't seen any issues.
I think a bigger recipe for failure is not staying on top of your oil change intervals,and using a good quality oil filter,and long idle times.
There is a caveat though,as i don't know of anybody who's deleted it via just a tune or using the steering wheel buttons,and made a 100,000+ miles,with-out a lifter failure.
I'm hoping somebody who has made it over a 100,000 miles with MDS deleted via a tune,and hasn't had a lifter failure,will post.

My 5.7 knows that if it throws a lifter its getting kicked out and replaced with a 6.4 so no doubt that's helping me out here.

 

[G-Ride990]

Drove my truck to work this morning with MDS still active, first time since I can remember not turning it off with gear +/-.

To and from work is about 20 minutes each way.

HATED it! On the freeway wasn't bad unless I was coasting or decelerating but surface street speeds... Good lord I need a muffler now.

MDS delete/cam/converter may be on the list soon.

 

[Wild one]

My 5.7 knows that if it throws a lifter its getting kicked out and replaced with a 6.4 so no doubt that's helping me out here.

It'll never die if it knows you're gonna replace it with a 6.4,lol

 

[ramffml]

Still trying to understand this better. So what I’m hearing is if you leave mds on, the 4 lifters get the lube that they need cause they are closed. If you turn it off they don’t. So are the 4 that stay open when mds is on not getting lubed ever? And if they are getting lubed, how come when the other 4 are open (mds off) they aren’t getting lubed?

When MDS is enabled and active (so 4 cylinders running only), while in that mode all 16 lifters apparently are getting fed extra oil as the MDS uses oil pressure to collapse the lifters. When MDS is not running (or disabled), then those galleys are closed. So MDS active is also feeding the non MDS lifters when MDS is active.

If you disable MDS, or are constantly towing heavy preventing MDS from activating, then all 16 lifters are not being fed through those galleys.

 

[La Ramie]

…
I think a bigger recipe for failure is not staying on top of your oil change intervals,and using a good quality oil filter,and long idle times.
…

I think these are the main things with these engines.

 

[La Ramie]

When MDS is enabled and active (so 4 cylinders running only), while in that mode all 16 lifters apparently are getting fed extra oil as the MDS uses oil pressure to collapse the lifters. When MDS is not running (or disabled), then those galleys are closed. So MDS active is also feeding the non MDS lifters when MDS is active.

If you disable MDS, or are constantly towing heavy preventing MDS from activating, then all 16 lifters are not being fed through those galleys.

If you are saying shifting out of the MDS will cause oil not to be fed to the lifters, then this design is asking for a failure by not lubricating the moving parts.

 

[Wild one]

If you are saying shifting out of the MDS will cause oil not to be fed to the lifters, then this design is asking for a failure by not lubricating the moving parts.

I'm guessing you haven't watched the video yet,lol. It does a pretty decent job of explaining how the system works,it's worth spending the 16 minutes it takes to watch it.

 

[Wild one]

Reignited does push the high volumn pumps,but from everything i've seen the high volumn pumps don't really create any more flow or pressure at the stock 580/600 rpm as the stock pump creates if the idle is upped to 750+rpm,plus you'll get more oil flung off the crank onto the lobes at 750 rpm,then you will with an idle speed of 600 or less.

 

[Wild one]

About the 14 minute mark on this video,if you look close you can see scoring on the side of the lifter,which might be an issue related to lack of oil flow to the lifter bores.

5.7 HEMI Lifter Failure Could this FIX the lifter issue FOREVER?

Hey guys, revisiting the 5.7 HEMI lifter failure video I made a couple months ago. I wanted to address many off the comments that I got from the last video, ...

www.youtube.com

 

[JHoward]

Lol, this thread has given me an headache.

 

[crackerjack1957]

I'm a little confused also if this info is correct from Summit Racing.

1. The computer shuts off fuel to the MDS controlled cylinder.
2. Then the computer opens the MDS solenoid which supplies oil pressure to the lifter deactivation ports.
3. This oil pressure passes through the hole in the side of the lifter and decouples the inner plunger from the lifter body. This “deactivates” the lifter.

So MDS solenoids are open when MDS is activated allowing oil pressure to decouple lifters.
MDS solenoids are closed when all lifters/valves are working on all 8 cylinders.
So how can this be bad on stock engines?

I can see how plugs could help flow on non-MSD cams/lifters by not flowing around/thru solenoids.
But cutting MDS off should not harm valvetrain by the above info if it is indeed correct.
I've been wrong before so someone show me otherwise.......LoL

Hemi Engine Tech - Multi Displacement System (MDS) · Help Center

 

[Wild one]

I'm a little confused also if this info is correct from Summit Racing.



So MDS solenoids are open when MDS is activated allowing oil pressure to decouple lifters.
MDS solenoids are closed when all lifters/valves are working on all 8 cylinders.
So how can this be bad on stock engines?

I can see how plugs could help flow on non-MSD cams/lifters by not flowing around/thru solenoids.
But cutting MDS off should not harm valvetrain by the above info if it is indeed correct.
I've been wrong before so someone show me otherwise.......LoL

Hemi Engine Tech - Multi Displacement System (MDS) · Help Center

The solenoids cut off oil flow to the lifter gallery that surrounds the lifter. That reduces the pressurized oil that is fed to the lifter bores,so basically you end up with a lifter that is running with minimial pressurized oil to the external sides of the lifter and it's bore.Some of that pressurized oil still leaks past the lifter and it's bore,and hopefully drips onto the cam lobe and roller wheel.Reducing the oil pressure to the lifter bore,also leads to lifter scoring

 

[crackerjack1957]

The solenoids cut off oil flow to the lifter gallery that surrounds the lifter. That reduces the pressurized oil that is fed to the lifter bores,so basically you end up with a lifter that is running with minimial pressurized oil to the external sides of the lifter and it's bore.Some of that pressurized oil still leaks past the lifter and it's bore,and hopefully drips onto the cam lobe and roller wheel.Reducing the oil pressure to the lifter bore,also leads to lifter scoring

Ok, just seen the end of that video you linked.
I see how MDS on creates more flow to those areas.

How about about writing me a tune to keep my MDS solenoids on to help lubricate my non-MDS cam/lifters without a cell........LoL

 

[JHoward]

Ok ... so, now it is correct to not manually disable MDS ...?

... because, and yes I've viewed the video.

 

[JHoward]

... I've a family that has an 2012 5.7 HEMI RAM with just a little over 60,000 miles ... he has never turned off MDS, and wouldn't even know how, and has a slight lifter tick that he can't even hear, drives it like "paw paw skibblebanks" and thinks everything I've informed him about the Gen 3 HEMI isn't a concern and that I read to much, lol ... so, that's one HEMI that "rattles" and has never had MDS manually turned off ...

 

[Wild one]

... I've a family that has an 2012 5.7 HEMI RAM with just a little over 60,000 miles ... he has never turned off MDS, and wouldn't even know how, and has a slight lifter tick that he can't even hear, drives it like "paw paw skibblebanks" and thinks everything I've informed him about the Gen 3 HEMI isn't a concern and that I read to much, lol ... so, that's one HEMI that "rattles" and has never had MDS manually turned off ...

I'd lay odds if he's driving it like Grandma,that's probably got more to do with it,then turning the mds off,lol.The Hemi's not an engine that takes kindly to being babied,they'd rather you drive them like you stole it,lol. Running around town just above idle means the mds system never activates

 

[Wild one]

Ok, just seen the end of that video you linked.
I see how MDS on creates more flow to those areas.

How about about writing me a tune to keep my MDS solenoids on to help lubricate my non-MDS cam/lifters without a cell........LoL

That's not a bad idea CJ,be easier then swapping out the solenoids for the plugs,although i'm not sure if that would trip a code or not,but i'd think it shouldn't