Hemi Camshaft Failure Mystery Explained

[jerem0621]

Somewhat of a mystery over the years has been these random roller camshaft failures in modern Hemis. Uncle Tony just made a video explaining his findings on the issue.

If you are interested here is a Link

Thanks,

Jeremiah

[garyp4951]

The drain area around the top of the lifter described at 9:22 is the problem I agree with.

[bguy]

I guess the only thing to do is let er rip... just as the engineers designed it.

[ddown]

They changed the Lifters Mid-Year 2016 to a Melling more robust design different part #

[dodge_guy]

Yes the lifters are on backorder. But again we don't see the failures that others see! And we see a lot of Hemi powered vehicles. The last Hemi engine issue we had was a broken valve spring in a police car. Not saying the lifters don't have a design issue/flaw. They were on backorder before their Covid **** started, but now they are trying to catch up to demand. So it's hard to say right now what they are on backorder.

[ksss]

dodge guy wrote:

ksss wrote:

dodge guy wrote:

ksss wrote:

hvac wrote:
It appears idling is what accelerates the failure. If so police applications must be experiencing high failure rates.

That is true, incredible failure rates here locally. The 2011-2014 seem to be the worst. The local pd has auctioned off the majority of Chargers. The City mechanics are continually pulling these apart, repairing them only to have to do it again. Really something not right with this engine.

We do work for a couple of towns around us. It’s not idling. It’s the geometry of the cam and lifters in relation to the pushrod/rocket arm. Also the poor quality roller bearings in the lifter. With the amount of Hemis on the road the failure rate is very minimal.

What the reason is for the failure, I am not sure maybe idling or poor components, but to say it is minimal simply is not true.

Well we are a larger dealer in a big suburb. If anyone would see them fail at an alarming rate it would be us. Like I said we only see a handful a year.

I had a second today and I swung by the City shop (reference this thread) as I know some of the mechanics. In the bay was a 2014 Hemi police car with 60K on it. Valve train out. I asked the mechanic for his take on these. He leads me over and starts pulling cam shafts and lifters off the shelf. Points out the flattened out lobes and the lifters smashed down on themselves. Pretty clear the lifter locked up and took out the cam shaft. I took pics but this website is a PINTA for posting pics. Each mechanic has their camshafts from the repairs they have done. There are others that were done by the dealer. They tried aftermarket lifters and the life was even shorter. According to the dealer the mechanic said that there are 18K lifters on backorder. Many cars are dead lined and auctioned off, way short of the anticipated life span. I mentioned this thread, the mechanic had a lot to say about these engines and would gladly share what they have experienced. These are all LE cars, and are subject to prolonged idle time. The oil is changed at 5K, maybe as some have said is part of the issue, certainly poor engineering is as well. The pd has deadlined 13 of the 33 Chargers that they still have. If the dealer is telling the truth about the out of stock lifters, certainly this isnt isolated to what we see in our area.

[hvac]

That's good to hear, she's a garage queen with nothing but synthetic since new. Its a great car and love that hemi when its occasionally asked to perform.

[dodge_guy]

hvac wrote:
I have 2012 300c awd. My favorite car ever, but at 95k miles I'm concerned. She is noisy on cold starts. Hemi tick and it lasts for a couple of miles.

I also have a 2012 300C AWD. Mine also has the tick. But that tick is piston slap. That has been normal for years even on the GM V-8's. Mine has 60k miles. I'm not worried about it thoug. Keep the oil changed every 4K with synthetic and all will be good.

I personally think the failures are from lack of maintainance, extended idling, and abuse. Most of th failures we see are in trucks, a couple in cars. I know one year we had about 6 failures. 4 were in 2500 trucks and 2 were in cars. Rarely do you hear of a Grand Cherokee or Durango with a failure.

[dodge_guy]

ksss wrote:

dodge guy wrote:

ksss wrote:

hvac wrote:
It appears idling is what accelerates the failure. If so police applications must be experiencing high failure rates.

That is true, incredible failure rates here locally. The 2011-2014 seem to be the worst. The local pd has auctioned off the majority of Chargers. The City mechanics are continually pulling these apart, repairing them only to have to do it again. Really something not right with this engine.

We do work for a couple of towns around us. It’s not idling. It’s the geometry of the cam and lifters in relation to the pushrod/rocket arm. Also the poor quality roller bearings in the lifter. With the amount of Hemis on the road the failure rate is very minimal.

What the reason is for the failure, I am not sure maybe idling or poor components, but to say it is minimal simply is not true.

Well we are a larger dealer in a big suburb. If anyone would see them fail at an alarming rate it would be us. Like I said we only see a handful a year.

[parker_rowe]

azdryheat wrote:
I've built a few engines in my time and this guy makes a whole lot of sense. Ain't no way I'd ever have a modern Hemi, which, BTW needs to be recalled and replaced. The original 426 Hemi was bullet proof. I don't know why Dodge didn't just repeat that design in a smaller engine.

Because the original Hemi was terribly inefficient. It would never make it on todays emissions targets.

The huge combustion chamber required big piston domes to get decent compression ratio's. Which also required lots of ignition advance to make sure you had enough time for a semi decent burn of the air fuel mixture.

It made power because it had tons of cylinder head flow for the time, due to the valve angles created by the hemispherical combustion chamber. These valve angles also created a physically huge engine that had nothing to do with the displacement.

Now we have modern engines that can get the same CFM with smaller ports and more efficient combustion chamber designs. All this leads to more power, cleaner burn, and more efficiency.

[ksss]

dodge guy wrote:

ksss wrote:

hvac wrote:
It appears idling is what accelerates the failure. If so police applications must be experiencing high failure rates.

That is true, incredible failure rates here locally. The 2011-2014 seem to be the worst. The local pd has auctioned off the majority of Chargers. The City mechanics are continually pulling these apart, repairing them only to have to do it again. Really something not right with this engine.

We do work for a couple of towns around us. It’s not idling. It’s the geometry of the cam and lifters in relation to the pushrod/rocket arm. Also the poor quality roller bearings in the lifter. With the amount of Hemis on the road the failure rate is very minimal.

What the reason is for the failure, I am not sure maybe idling or poor components, but to say it is minimal simply is not true.

[hvac]

I have 2012 300c awd. My favorite car ever, but at 95k miles I'm concerned. She is noisy on cold starts. Hemi tick and it lasts for a couple of miles.

[Grit_dog]

FishOnOne wrote:
I visited a Ram dealer back in early March to look at some Jeep Wranglers and couldn't help notice that 50% of RAM HD trucks on the lot were powered by Hemi engines. I've never seen this many in HD trucks and this area is surrounded by farmers and ranchers who historically purchased diesels for the most part.

Prolly because they sold all the diesels and were sitting on the last 9 months of Hemi trucks! Lol.

[dodge_guy]

ksss wrote:

hvac wrote:
It appears idling is what accelerates the failure. If so police applications must be experiencing high failure rates.

That is true, incredible failure rates here locally. The 2011-2014 seem to be the worst. The local pd has auctioned off the majority of Chargers. The City mechanics are continually pulling these apart, repairing them only to have to do it again. Really something not right with this engine.

We do work for a couple of towns around us. It’s not idling. It’s the geometry of the cam and lifters in relation to the pushrod/rocket arm. Also the poor quality roller bearings in the lifter. With the amount of Hemis on the road the failure rate is very minimal.

[FishOnOne]

I visited a Ram dealer back in early March to look at some Jeep Wranglers and couldn't help notice that 50% of RAM HD trucks on the lot were powered by Hemi engines. I've never seen this many in HD trucks and this area is surrounded by farmers and ranchers who historically purchased diesels for the most part.