Good Write up On 5.7 Hemi Issues

Status
Not open for further replies.
Joined
Feb 26, 2014
Messages
597
Location
Ontario, Canada
It seems that MDS is not so much the issue as manufacturer defect that they knew about, excerpting to much forces on parts, and lubrication issues were key, and using heavier weights only made it worse.

Dr. Andy Randolph, technical director at ECR Engines—a NASCAR engine developer based out of Welcome, North Carolina whose lab does lots of failure analyses—gave me his thoughts, too, positing that perhaps there was an issue with oil viscosity. The result would yield the excessive lash that the above R&D engineer told me about:

First, these lifters control lash hydraulically and are designed for 5W20 oil. If the owner uses a heavier oil (for instance a 10W30), this could impede the hydraulic action of the lifters and increase lash between the roller and cam lobe under some operating conditions. This increase in lash will generate impact loading when the lifter contacts the lobe and lead to premature failure of the needle bearings along with the ticking noise that some of the owners report.

Second, the needle bearings are fed oil continuously through the body of the lifter. Once again, if the owner uses a heavier oil then flow to the bearing will be reduced and failure could happen prematurely.

Though not familiar with the Hemi's MDS, Randolph says he doesn't think the cylinder deactivation system is playing a role based on what he's seeing here. In addition, both he and the R&D engineer don't think this failure should lead to bent pushrods, though Randolph did add that it could happen if "the lash increases sufficiently for the pushrod to be displaced from the cup in either the lifter or the rocker arm. Once displaced, the pushrod could easily become overloaded and bend." That's what I think happened, but that's just a guess..

In any case, it's pretty clear that a fault in the lifter's ability to control lash—possibly caused by debris or improper oil viscosity—could theoretically be the cause of these failures.

https://jalopnik.com/chrysler-built-hemi-engines-with-a-major-engineering-de-1842400890
 
Last edited:
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.



Not sure, not up to snuff on 6.4 to tell you truth, does 6.4 have MDS as well?
 
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.
 
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.



Not sure where he said 5 20 or else, as he said this is his theory.....which makes complete sense, he states 10 30 and probably means above that.

But what what a NASCAR engine developer know.
 
Last edited:
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.


And get a bag, or something that holds liquid, now cut a hole...now put thin liquid and push it through...then do same with thicker fluid, let me know the pressures required to get the thicker fluid through that hole. Like it's common sense and people want to create a argument. I will take his word over someone random on a forum who thinks it's not true because he doesn't believe it.
 
Seems as though the rollers in the lifters failed because of the high spring pressure & the under size required to fit the lifter bore.
Bad engineering?. Poor metallurgy?
 
Originally Posted by domer10
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.


And get a bag, or something that holds liquid, now cut a hole...now put thin liquid and push it through...then do same with thicker fluid, let me know the pressures required to get the thicker fluid through that hole. Like it's common sense and people want to create a argument. I will take his word over someone random on a forum who thinks it's not true because he doesn't believe it.


Okay, so what's supposed to happen when someone goes out and starts his pickup on a cold morning?
The 5W-20 is then thicker than a 10W-30 would be on a warmer morning.
This is the reason that I don't think this theory has any validity.
Viscosity is always and everywhere a function of temperature and it doesn't take any great reduction in starting temperature for a 5W to be thicker than a 10W.
Next up theory?
 
Originally Posted by domer10
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.


And get a bag, or something that holds liquid, now cut a hole...now put thin liquid and push it through...then do same with thicker fluid, let me know the pressures required to get the thicker fluid through that hole. Like it's common sense and people want to create a argument. I will take his word over someone random on a forum who thinks it's not true because he doesn't believe it.


Same lifter, same basic engine other than displacement, different recommended viscosity. If a higher viscosity causes failures, than surely there would be more dead 6.4L on the side of the road.
 
Originally Posted by domer10
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.



Not sure where he said 5 20 or else, as he said this is his theory.....which makes complete sense, he states 10 30 and probably means above that.

But what what a NASCAR engine developer know.


He already said he's not familiar with the design. We got into the design in a previous thread, IN DETAIL on here.

Cliff-notes:
- The SRT engines use the same MDS components and spec 0w-40. Their lifter failure rate appears to be lower.
- Oil viscosity is heavily temperature dependant. If the system was indeed this viscosity sensitive, they would fail far more frequently in northern climates, which is clearly not the case.
- When the lifter rollers seize up, this often goes unnoticed and can result in a dramatic amount of wear of both the cam lobe and the lifter, making the lifter shorter. This would allow the pushrod to dislodge and once the lifter is no longer locked in the retainer keeping it straight, it bouncing around could certainly result in a scenario where the pushrod gets bent.

The FCA MDS and the GM's AFM are essentially the same system and both experience the same lifter failure. The difference is that GM uses a billet camshaft core, whilst FCA opted for SADI, so on the FCA engines the cam always needs to be replaced, where this is not the case with the GM engines.

Lifter failure is also not isolated to the MDS lifters. In many cases, the lifter(s) that fail are the regular ones. On top of that, engines without MDS have also experienced the problem. I provided links to examples of this in the previous thread. At this point, both GM and FCA have gone through several part revisions and the issue is believed to have been fixed, though we'll see how that pans out.

Keep in mind, the vast majority of HEMI engines (and GM AFM ones) never experience the issue.
 
Originally Posted by CT8
Good Write up On 5.7 Hemi Issues What exactly is good about it?



Gets in depth to heart of issues, of course not good enough for you....but enlightened me as to much more going on than MDS.

Why exactly did it not cut the mustard for you?
 
Originally Posted by OVERKILL
Originally Posted by domer10
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.



Not sure where he said 5 20 or else, as he said this is his theory.....which makes complete sense, he states 10 30 and probably means above that.

But what what a NASCAR engine developer know.


He already said he's not familiar with the design. We got into the design in a previous thread, IN DETAIL on here.

Cliff-notes:
- The SRT engines use the same MDS components and spec 0w-40. Their lifter failure rate appears to be lower.
- Oil viscosity is heavily temperature dependant. If the system was indeed this viscosity sensitive, they would fail far more frequently in northern climates, which is clearly not the case.
- When the lifter rollers seize up, this often goes unnoticed and can result in a dramatic amount of wear of both the cam lobe and the lifter, making the lifter shorter. This would allow the pushrod to dislodge and once the lifter is no longer locked in the retainer keeping it straight, it bouncing around could certainly result in a scenario where the pushrod gets bent.

The FCA MDS and the GM's AFM are essentially the same system and both experience the same lifter failure. The difference is that GM uses a billet camshaft core, whilst FCA opted for SADI, so on the FCA engines the cam always needs to be replaced, where this is not the case with the GM engines.

Lifter failure is also not isolated to the MDS lifters. In many cases, the lifter(s) that fail are the regular ones. On top of that, engines without MDS have also experienced the problem. I provided links to examples of this in the previous thread. At this point, both GM and FCA have gone through several part revisions and the issue is believed to have been fixed, though we'll see how that pans out.

Keep in mind, the vast majority of HEMI engines (and GM AFM ones) never experience the issue.



Ok but this isn't about the 6.4, it's about the 5.7, and 0 40 can be thinner than a thicker 10 30. And there is a mast majority of 5.7 that experience the symptoms before it leads to catastrophic failure. I had a 2012 and within 45k the tick was getting bad, and I had always wondered about it and would read in here of same gen Hemi having failures.

Like I said I have no idea about the 6.4 and it seems from 14 on they started getting a handle on it somewhat.
 
Last edited:
Originally Posted by OVERKILL
Originally Posted by domer10
Originally Posted by Skippy722
Originally Posted by Sunnyinhollister
I thought the 6.4L Hemi uses the same lifters as the 5.7L, however the 6.4L specs a 0W-40 viscosity and the 5.7L calls for a 5W-20.


They do. The "5w20 or else!" thing is complete nonsense.



Not sure where he said 5 20 or else, as he said this is his theory.....which makes complete sense, he states 10 30 and probably means above that.

But what what a NASCAR engine developer know.


He already said he's not familiar with the design. We got into the design in a previous thread, IN DETAIL on here.

Cliff-notes:
- The SRT engines use the same MDS components and spec 0w-40. Their lifter failure rate appears to be lower.
- Oil viscosity is heavily temperature dependant. If the system was indeed this viscosity sensitive, they would fail far more frequently in northern climates, which is clearly not the case.
- When the lifter rollers seize up, this often goes unnoticed and can result in a dramatic amount of wear of both the cam lobe and the lifter, making the lifter shorter. This would allow the pushrod to dislodge and once the lifter is no longer locked in the retainer keeping it straight, it bouncing around could certainly result in a scenario where the pushrod gets bent.

The FCA MDS and the GM's AFM are essentially the same system and both experience the same lifter failure. The difference is that GM uses a billet camshaft core, whilst FCA opted for SADI, so on the FCA engines the cam always needs to be replaced, where this is not the case with the GM engines.

Lifter failure is also not isolated to the MDS lifters. In many cases, the lifter(s) that fail are the regular ones. On top of that, engines without MDS have also experienced the problem. I provided links to examples of this in the previous thread. At this point, both GM and FCA have gone through several part revisions and the issue is believed to have been fixed, though we'll see how that pans out.

Keep in mind, the vast majority of HEMI engines (and GM AFM ones) never experience the issue.


And thanks for the info on the 6.4.
 
Originally Posted by domer10
[Ok but this isn't about the 6.4, it's about the 5.7,

But they use the exact same MDS parts.

Originally Posted by domer10
[and 0 40 can be thinner than a thicker 10 30.

At lower temperatures. At above 0, the 0w-40 is thicker. Most PCMO 10w-30 are a fair bit thinner than a >3.5 HTHS 0w-40.

Originally Posted by domer10
[And there is a mast majority of 5.7 that experience the symptoms before it leads to catastrophic failure.

And most owners don't act on them, which is why the damage tends to get so extensive.

Originally Posted by domer10
[I had a 2012 and within 45k the tick was getting bad, and I had always wondered about it and would read in here of same gen Hemi having failures.

Like I said I have no idea about the 6.4 and it seems from 14 on they started getting a handle on it somewhat.


Yes, they updated the lifters sometime ~2014, which is when most think it got fixed.
 
Originally Posted by domer10
And thanks for the info on the 6.4.


No problem! If this topic interests you, you'd probably REALLY enjoy the other thread.
 
Originally Posted by OVERKILL
Originally Posted by domer10
[Ok but this isn't about the 6.4, it's about the 5.7,

But they use the exact same MDS parts.

Originally Posted by domer10
[and 0 40 can be thinner than a thicker 10 30.

At lower temperatures. At above 0, the 0w-40 is thicker. Most PCMO 10w-30 are a fair bit thinner than a >3.5 HTHS 0w-40.

Originally Posted by domer10
[And there is a mast majority of 5.7 that experience the symptoms before it leads to catastrophic failure.

And most owners don't act on them, which is why the damage tends to get so extensive.

Originally Posted by domer10
[I had a 2012 and within 45k the tick was getting bad, and I had always wondered about it and would read in here of same gen Hemi having failures.

Like I said I have no idea about the 6.4 and it seems from 14 on they started getting a handle on it somewhat.


Yes, they updated the lifters sometime ~2014, which is when most think it got fixed.


Even without catastrophic failure you have to admit that replacing the parts that will lead to failure is still no easy feat. And that Chrysler knew that this was a issue, not just in that story but multiple fourms where people's bit the dust at below 100 even below 80 k.
 
Originally Posted by domer10
Even without catastrophic failure you have to admit that replacing the parts that will lead to failure is still no easy feat. And that Chrysler knew that this was a issue, not just in that story but multiple fourms where people's bit the dust at below 100 even below 80 k.


Yes, as clinebarger's recent thread details, changing the cam and lifters is a huge PITA. And yes, both Chrysler and GM knew about the issue, which I assume is supplier related, and them using the same supplier. I can't believe it took as long as it did to get sorted.
 
Originally Posted by OVERKILL
Originally Posted by domer10
And thanks for the info on the 6.4.


No problem! If this topic interests you, you'd probably REALLY enjoy the other thread.



It does! could you please send link? Or is it already in previous post?
 
Originally Posted by domer10
Originally Posted by OVERKILL
Originally Posted by domer10
And thanks for the info on the 6.4.


No problem! If this topic interests you, you'd probably REALLY enjoy the other thread.



It does! could you please send link? Or is it already in previous post?


It's not, let me dig it up, give me a few.
 
Status
Not open for further replies.
Back
Top