5.7 HEMI Lifter/cam failure cause

[carviewsonic]

Originally Posted by OVERKILL
Originally Posted by carviewsonic
Excellent video, clearest explanation I've seen so far.
My company 2018 Hemi Ram 1500 sometimes ticks noticeably on cold starts. At work a few of the Hemi pick-ups that went to auction had the 'Hemi tick' at idle, but they have all had approx. 300k kms or higher. Haven't had any lower mileage cam failures that I'm aware of.


All our work trucks developed a cold start tick, and all of them were rectified with an exhaust stud change and re-seal of the manifolds. Seems to be the most common cause.


Our mechanic has done a few of these also.

 

[clinebarger]

What he states is not 100% correct, There are Lifter Bore Lube galleys that run under the lifter bores, The Pre MDS Hemi's have 2 galleys that are fed full oil pressure & the MDS Hemi's have 4 that are fed reduced oil pressure during 8 cylinder mode & Higher oil pressure during 4 cylinder mode. Non MDS with MDS Block Hemi's are fed full oil pressure.

 

[Chris142]

Originally Posted by clinebarger
What he states is not 100% correct, There are Lifter Bore Lube galleys that run under the lifter bores, The Pre MDS Hemi's have 2 galleys that are fed full oil pressure & the MDS Hemi's have 4 that are fed reduced oil pressure during 8 cylinder mode & Higher oil pressure during 4 cylinder mode. Non MDS with MDS Block Hemi's are fed full oil pressure.

But do any of them drop oil where it needs to be?

 

[WyrTwister]

My guess the failures are due to bad metallurgy ?

 

[OVERKILL]

Originally Posted by Chris142
But do any of them drop oil where it needs to be?


The lifter bores are all pressure lubricated, so him going on about scuffing and deposits? The bores are NOT splash lubricated, they sit in a pressurized state where side leakage, both up and down, keeps them lubricated. There's an orifice in the side of the non-MDS lifters that lets oil into the lifter where it goes up the pushrod and then down the adjacent pushrod into the MDS lifter, which are internally lubricated "backwards".

As I stated in the other thread, I believe the expectation is that there is sufficient side-leakage in the lifter bore/body interface that oil makes its way down to the roller/lobe interface (there's a hole in the bottom of the MDS lifters, some non-MDS lifters seem to show a slot, other pictures don't, so we are unclear on that bit). I posted an MDS lifter breakdown in the other thread as well, earlier on.

 

[JTK]

There's about 8 of us with later model Ram 1500 hemis at work (that I can think of ATM), ranging from 2013 to 2020. Some have miles in the low 100K range. I know most of them don't even know their engines have MDS, let alone how it works. Some follow the OLM right down to zero % or very low %. One guy with a 2014 on my shift lives close to the plant and has very low mileage at around 45K on his truck, but he does 10K mile or 1yr oil changes with M1 5w20.

My point is none of them tick or have had any engine issues. This is obviously a tiny sample, but there are SO many Ram hemis out there these days it's difficult to call this a 'definitely is going to happen to you' problem.

I rarely keep my vehicles past ~70K miles, so I'll be a lousy representative as well.

I always say, subsequent owners of my vehicles better appreciate my efforts. LOL

 

[Danno]

Found this video, and a Hemi engineer comments on why these failures may be happening.
He thinks its improper heat treatment of the cam lobes. Look for Clifford Grupke comments

 

[doublebase]

There's about 8 of us with later model Ram 1500 hemis at work (that I can think of ATM), ranging from 2013 to 2020. Some have miles in the low 100K range. I know most of them don't even know their engines have MDS, let alone how it works. Some follow the OLM right down to zero % or very low %. One guy with a 2014 on my shift lives close to the plant and has very low mileage at around 45K on his truck, but he does 10K mile or 1yr oil changes with M1 5w20.

My point is none of them tick or have had any engine issues. This is obviously a tiny sample, but there are SO many Ram hemis out there these days it's difficult to call this a 'definitely is going to happen to you' problem.

I rarely keep my vehicles past ~70K miles, so I'll be a lousy representative as well.

I always say, subsequent owners of my vehicles better appreciate my efforts. LOL

I know two guys that work for Dodge dealers, I’ve asked them both about this issue...they both say it’s not something they see often. One did say, yeah sometimes we see cams ground down, but it’s pretty rare/earlier models.

I owned a 2018 Silverado and the collapsed lifters were a big story with those trucks on their active fuel management cylinder shut off systems, but again, guys at the dealer say it’s not something they see all that often. It’s overblown on the internet, like everything else. And I too had 5-6 friends at work that owned the same Silverado - none of them knew they even had active fuel management and potential problems awaiting - and all of these guys drove those trucks into the ground. Not one of them/us had a single issue with lifters. Now AC condenser, starters and frame rust? All of us. Four of us had our starters fail within three months of each other. I ended up selling mine because I thought my tranny was going to grenade right after my power train warranty, but the engine was the least of my worries.

 

[4WD]

Originally Posted by farrarfan1
If he's right about it being caused by a design flaw then it doesn't seem like we, as owners of HEMI equipped vehicles, can do much about it is there? If oil isn't reaching the cam then how can using a different viscosity than what's recommended by FCA going to help?


It wouldn't, as you astutely determined. Also, in the plenty of HEMI lifters that Iv'e seen pictures of, I've not, from failed examples, seen ones with the deposits and scuffs that his had. The bores are pressure lubed, not splash, it's the cam/roller interface that's primarily lubed via splash and it's certainly possible that extensive idling with low levels of oil sling could contribute to roller failure if insufficient oil is leaking past the lifter body and onto the lobe.

If oil flows via the push rod … how much fluid area are we talking ?

 

[OVERKILL]

If oil flows via the push rod … how much fluid area are we talking ?

Don't know, but oil delivered via the pushrod is pretty standard for OHV pushrod engines.

 

[JTK]

If oil flows via the push rod … how much fluid area are we talking ?

Apparently it's enough to lubricate the rocker arms and everything under the valve covers because you don't hear of many issues with that on hemis that I'm aware.