Gen 3 Hemi Cam Shaft Issues?

Fratzog

Old Man with a Hat
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I came across this and it peaked my interest because I have a 5.7 in the Ram. I'd particularly be interested in hearing from anyone who routinely services these engines and if they can verify what Tony is saying.
 
Cam and lifter issues, it seems, were also on some model years of the Chrysler 3.6L, too. We hired a younger guy for our heavy line shop. He was doing one and I asked about it. He said that apparently they tried to "cheap-out" on the supplier, for a few model years or something.

Apparently, there were some issues with the GM 6.0L pickup truck motors. We had a company box van that would need a new cam (and a few lifters with their plastic retainers) every 70K miles, as long as we had it from new. We had the cam retainer trays in stock! So obviously not a really isolated instance? One lifter would rotate a bit, causing a slight/different "tick", but it also lost a bit of power on the hills. ONE of a long line of GM cam/lifter issues over the past 20 years!

Thanks for the link!
CBODY67
 
Cam and lifter issues, it seems, were also on some model years of the Chrysler 3.6L, too. We hired a younger guy for our heavy line shop. He was doing one and I asked about it. He said that apparently they tried to "cheap-out" on the supplier, for a few model years or something.

Apparently, there were some issues with the GM 6.0L pickup truck motors. We had a company box van that would need a new cam (and a few lifters with their plastic retainers) every 70K miles, as long as we had it from new. We had the cam retainer trays in stock! So obviously not a really isolated instance? One lifter would rotate a bit, causing a slight/different "tick", but it also lost a bit of power on the hills. ONE of a long line of GM cam/lifter issues over the past 20 years!

Thanks for the link!
CBODY67

Longer than that 350cid Chev motors were running the cams flat back in the 1970's.

Dave
 
There is a ton of speculation out there. This actually makes the most sense and completely explains why a 250k highway engine outlast a 75k regular sit in traffic everyday commuter, along with police car 100k failures. So if you have one best not to sit in traffic for hours and you need to stand on it whenever possible.
Worst problem with the Chrysler engines are the $1600 set of lifters with zero aftermarket support.
 

After reading through that forum link and comments, it seems that the GF-5 and SN oils were at issue, which seems to be about the same time that the low speed pre-ignition issues later surfaced? Which resulted in piston failures in the ring package area.

The alleged "cure" was the later SN-PLUS oils. In watching the virgin oil analysis postings at www.bobistheoilguy.com, the SN+ oils had reduced calcium, but raised zddp to 800ppm, or about the levels from the prior SM oils. I was curious about that increased zddp, but from the postings in the link, it appears it might have also played into the camshaft issues?

When Chrysler changed from Mobil 1 to the Pennzoil SRT oil, I noticed that one difference in the postings of oil analysis, between the two, was about 1/2 the level of phosphorus from the levels in the prior-recommended M 1 oil. At the time, I suspected that they had reduced the size of the catalyst area and needed the different oil to compensate for it, still maintaining catalyst life expectancy. Or possibly due to oil consumption in the SRT motors?

A few years ago, BMW changed its oil supplier from Castrol to Pennzoil (or a better name, Royal Dutch Shell). My contact stated that BMW wanted Castrol to "do some things" with the oil, Castrol refused, and they changed to Royal Dutch Shell/Pennzoil. Wondering if the change of additive package might have played into that deal?

IF, as some of the comments in that link also play into the 0W__ viscosity issues, it might seem that the quest to have oils that flow instantly (cold or hot) might be slightly misguided? I remember when the 0W oils first came out and reading that they'd get everything lubed 40% (or thereabouts) sooner than a 5W oil might, which can be good for decreased start-up wear and also possibly cold start emissions? End result, kind of makes the old 10W-30 oils look better in many respects? AND puts a new emphasis on reading the virgin/used oil analysis postings!

Thanks, Dave, for that link!!!
CBODY67
 
Longer than that 350cid Chev motors were running the cams flat back in the 1970's.

Dave
NOT to forget the roller lifter 350s' valve lifter rollers that lost sections of the rollers, in the 2000s! We did LOTS of those replacements, yet the GM reps denied that there was a wide spread problem. Even when the evidence was abundantly clear.

In the middle '80s, I think that many of the camshaft issues might have been deemed "hot fuel handling" issues. Had plenty of that, but did a cam replacement in one Monte Carlo 305 with those issues and the new cam fixed it. Don't know if the fuel pump cam lobe was the issue, by itself, though.

Sometimes, you have to watch how these things develop and play out to determine what the REAL issue probably was.

Thanks, again, for that link!
CBODY67
 
I came across this and it peaked my interest because I have a 5.7 in the Ram. I'd particularly be interested in hearing from anyone who routinely services these engines and if they can verify what Tony is saying.

Interesting inspection and also the letter inferring oil qualities.
Couldn’t one insert a splash tray or something similar to get oil draining from the valley onto the cam lobes? Additionally, maybe an orificed spray nozzle to spray oil onto the cam lobes and lifter roller?
While it appears to be a design flaw, I am unsure oil type is a culprit. I wonder if Steve (the guy who wrote the letter in the second link) had seen the video showing the lack of oil being splashed onto the cam lobes and lifter base...
 
Several guys in the genIII forum on moparts have experience with seeing different failures if you have specific questions
 
Thanks for the comments and links. It is interesting that Steve didn't see the same discolouration pattern on the lifters. So my take away is that oil supply vs oil quality seems to be the debate. I had to look up stiction LOL.
 
I am on my second 300C with the 5.7Hemi.
Love these cars! Excellent daily drivers and long haul cars with all the creature comforts
Never had any issues with the engines.
340Demon and boab 008.JPG
300 first Christmas.JPG
 
Unless oil management/drain-back routes have changed with the newer engines, the camshaft lobes have always had "splash" lubrication. I would think that the roller lifter engines might need less oil on the lobes than the sliding flat tappet designs? Even when many OEMS went to roller lifters in the '80s, no failures that we heard of. With oil that usually had greater levels of zddp and such, too. Only issue with cat converters, back then, was lead and other fuel additives.

Just some thoughts,
CBODY67
 
I have seen numerous forum comments on the "best oil" to use. Almost never is mentioned Chrysler's requirement for their MS6395 spec. Most oils either don't meet it or don't want to certify to the spec.

What Is Hemi MDS?

A few things can happen that can cause this mechanism to break down, the most common of which is oil contamination (change your oil). When small pieces of dirt block the lube circuit, the lifter may not be able to change state, or the change may happen slower, or only partially. A common scenario with the MDS system in Hemis is where the ECM believes the lifter is engaged at higher rpm when it is not. Here, the internal pin that locks the lifter body to the plunger is still disengaged when the engine rpm goes up. In this failure mode, the roller follows the cam lobe, until it reaches an engine speed where it can't, and the roller crashes repeatedly on the lobe. Eventually, the lifter, roller, needle bearings, and the lobe surface become damaged to the point of failure.
 
I think it would be useful to do a similar analysis of a "pre-magnum" roller cam LA to see what it's architecture and cam oiling looks like.
 
I have seen numerous forum comments on the "best oil" to use. Almost never is mentioned Chrysler's requirement for their MS6395 spec. Most oils either don't meet it or don't want to certify to the spec.

What Is Hemi MDS?

A few things can happen that can cause this mechanism to break down, the most common of which is oil contamination (change your oil). When small pieces of dirt block the lube circuit, the lifter may not be able to change state, or the change may happen slower, or only partially. A common scenario with the MDS system in Hemis is where the ECM believes the lifter is engaged at higher rpm when it is not. Here, the internal pin that locks the lifter body to the plunger is still disengaged when the engine rpm goes up. In this failure mode, the roller follows the cam lobe, until it reaches an engine speed where it can't, and the roller crashes repeatedly on the lobe. Eventually, the lifter, roller, needle bearings, and the lobe surface become damaged to the point of failure.
I concur on your view regarding oil testing specs. I run Amsoil in all of my vehicles. It is tested to that spec (MS-6395 and others). I also use Amsoil, Wix, Napa Gold (I believe Hastings), Donaldson, Hastings or Baldwin filters, in that order. I have learned that those filters (by cutting them open after use with a dremel tool) are of superior construction in the number of pleats, structural construction and materials.

The video showing the rust and wear indicates to me that the lifter is not getting sufficient oil, or the oil isn't ‘sticking’ to the lifter and lifter bore sufficiently. I also have analysis performed on the oil when I change it.
Regarding analysis, the biggest thing that I discovered was that I saw the Total Base Number (TBN) erode and when I changed the oil, it still was positive. The TBN measures an oil’s ability to fend off corrosion.
I also saw that the copper content rose on a Ford Fiesta months before a rod wrist pin sieved, which caused 2 nice egg-shaped holes in the block around cylinder #3. The wrist pin got so hot when it failed that it turned blue.
Interestingly, that rod had white paint writing on it - the other rods did not. I surmised that as that vehicle was built near the end of the model year (2007) that they were running out of parts and installed a ‘questionable’ or flagged rod to get the car out of the factory.

A little tangent, but I felt it important to share as it appears many here may benefit from what I have learned (I certainly do from many of you).
 
I think them biggest problem is people thinking they know more than the manufacturer. My 5.7 calls for Mobil 1 5-20 and my 6.1 calls for Mobil 1 0-40. I figured they recommend these weights for a reason so that is what I run. The 5.7 has 145K miles and the 6.1 has only about 60K. No issues with either one so far. (knock on wood) IMO, it is your car, do what you want with it but I follow the recommendations they put in the owners manual. From what some are saying, idle time could be causing issues. My cars don't get much idle time in traffic maybe that is what saves them. They don't know what babying means but I do maintain them to the best of my abilities.
 
I'd particularly be interested in hearing from anyone who routinely services these engines and if they can verify what Tony is saying.

Now that I've had time to actually watch the video, I'm not sure I'm following his logic? He starts out saying some of the lifter bores aren't fully lubricated? Right? Then he runs off complaining of a lack of splash lubrication on a roller lifter camshaft? It seems to me the runoff from the valley and lifter bores should be more than adequate for camshaft lubrication? What did I miss?
 
Now that I've had time to actually watch the video, I'm not sure I'm following his logic? He starts out saying some of the lifter bores aren't fully lubricated? Right? Then he runs off complaining of a lack of splash lubrication on a roller lifter camshaft? It seems to me the runoff from the valley and lifter bores should be more than adequate for camshaft lubrication? What did I miss?
One thing he says is that the runoff is too far to the side of the block to drip on the cam.
 
Okay, I see that now. I don't think splash is significant to roller camshaft lubrication.



I think the Hemi suffers from the same thing the 3.6 rockers suffer from, bad rollers. Note the lobes with good lifters are still good. No MDS to muddle the issue here. Looks like a nice color from lubrication shown here.
 
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