06 hemi 5.7 collapsed lifters

a_kelley

a_kelley

mechanical fixer
Joined
Jan 26, 2010
Location
Rutherfordton
Ok I just got a 06 hemi 5.7. it sat for at least 3 years. I drove 2 hours each way just to hear it before buying it, because sold as is. I heard it run before it came out and all the lifters are rattling, however it was running smoothly, so it's not like the lobes are wiped out. Ran it for about 30 seconds and it didn't clear up. The guy at the yard said that they ran it to try to get it to clear up. It's got 125k miles on it. The valve seats are intact. Question is do I install it like it is and try run oil & atf to get them to pump back up or just replace them while it's out.. here's a pic for reference.. I had to apply pressure to get the gap, but every single lifter is this way when it's on the base circle. Further question is if I do change them before installing it, would it be stupid to gamble with the set from the old motor? (I think it would be, but they're already here and I'm not so certain the lifters are very available) they are roller lifters & MDS.

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My dad recently bought a 12 ram with the same issue. He had lifters put in it, and it lasted at best a few days. He ended up replacing the engine, but I can not remember what the exact issue was that caused the new lifters to not last.
 
junkxj said:
My dad recently bought a 12 ram with the same issue. He had lifters put in it, and it lasted at best a few days. He ended up replacing the engine, but I can not remember what the exact issue was that caused the new lifters to not last.
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So it had sat for a few years and tapped from day one that he got it?

I suppose that I could do this another way and swap this crank, rods, & pistons into the old motor. And while I'm in there throw in a fresh set of rings.
 
I'm going to try pressurizing the oiling system with a pressure lube.. harbor freight sells them but some assembly required. Pics coming soon. with the system pressurized, the lifters will fill with oil and I'll test them under pressure and it should be difficult to depress the lifter.. just how much pressure does a lifter generate at say 40psi? Wouldn't that be = 40psi x surface area of the lifter in square inches? And then after the pressure is off, I should be able to slowly depress the lifter and oil should come out. I believe that should tell me if the lifters are good. I have a notion that the oil pump (gerotor) lost prime and has not regained it, thus pulling aerated oil, and would cause a repeat "failure" of good lifters, as in @junkxj s pop's truck.. at least that's my theory because I had another truck (ls though, same, crank driven oil pump) and figured that the oil pump would prime itself. Nope. You could rev it up and it would show oil pressure but if you let it idle it would drop to 0 and knock after several minutes, due to oil station aeration in the pump. All because the pump wasn't primed. When I pulled the oil gallery plug to check the threads, there was no oil in the gallery and this motor has had the filter on it since it ran Monday afternoon. That and the heads weren't covered in oil like they should've been. I'll find out here once I finish the adaptations to the not yet pressure oil luber.
 
Well I did the thing. Swapped lifters in from the old motor, runs good, no clicking clacking. The old motor sat for 4+ years so I bet the old ones would have pumped up.. I had one or two that were chattering at the start (the other motor sat for 9+ months) but after running at 3k for a minute, it shut up.
 
I've had similar issues, first thing I do is run a quart of Marvel in the oil. That stuff seems to bring lifters back from the dead.


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If all else fails, it sounds like the good brands of aftermarket lifters have effectively solved this problem. It's the expensive route though.
 
a_kelley said:
...just how much pressure does a lifter generate at say 40psi? Wouldn't that be = 40psi x surface area of the lifter in square inches? ....
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Seems like you've already solved your problem, but for your example -- 40psi x plunger bore area in square inches, if you were to dissect a lifter and measure it. That's how much pressure the plunger in the lifter body is pushing up against the pushrod with.
 
a_kelley said:
just how much pressure does a lifter generate at say 40psi? Wouldn't that be = 40psi x surface area of the lifter in square inches? And then after the pressure is off, I should be able to slowly depress the lifter and oil should come out. I believe that should tell me if the lifters are good.
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You shouldn't be able to bleed a lifter down by hand like that, because of how they work. That pressure times area is only the force that takes up the valve lash, and then they're hydraulically locked under compression because of the one-way nature of the check valves and orifices and whatever else that style of lifter design has in it. So they're effectively solid under compression, not oil pressure times area.

They probably needed to be bled, had aerated oil in them or whatever. They will be solid when you press on them with a pushrod if they don't need to be bled and aren't bad/leaky.
 
Fabrik8 said:
If all else fails, it sounds like the good brands of aftermarket lifters have effectively solved this problem. It's the expensive route though.
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Except this is an MDS motor and only place I think I can get them is the dealer. Nobody else had any in stock. For the non mds motor, yes.
 
Is MDS where it shuts down cylinders during cruise? You could always disable it, right?
 
Just for laughs, I thought I'd share. I hit the remote start on the truck this morning (I do most mornings, especially during the winter...don't hate, I'm a pampered p***y these days :lol: ) and when I walked out of the house and was locking the door, I heard a rhythmic tapping, almost knock-like sound. In my mind I freaked because I had just read this thread yesterday. But it was the rain tapping in the gutter downspout. :lol:
 
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