Engine Noise - Clatter at 3,000 RPM

[jsalbre]

Just my 2 cents from following the Pentastar rocker arm issue for a few years is that basically past mid 2014 or so when they addressed the rocker arm with a redesigned larger hole in the cup for better oil flow, that took care most of the needle bearing failure issues. After that to include the new upgrade Pentastar in our Gladiator, the main problem with rocker arm failures and cam lobe wiping is due to bad human assembly quality control and not so much a bad design.

When you say “bad human assembly quality control” do you mean the human that performed the assembly (verb, put it together) did a bad job, or that the human doing QC of the assembly (noun, combined parts) didn’t notice a problem they should have?

If the former, I’d think this would be something a semi-skilled person could inspect and correct before it becomes a problem.

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[Hootbro]

When you say “bad human assembly quality control” do you mean the human that performed the assembly (verb, put it together) did a bad job, or that the human doing QC of the assembly (noun, combined parts) didn’t notice a problem they should have?

If the former, I’d think this would be something a semi-skilled person could inspect and correct before it becomes a problem.

I am talking about the former. From the few repair video I have seen of independent mechanics doing a failed rocker arm replacement, it is a somewhat fiddly operation and they even admit can easily be misaligned and not noticed.

My speculative opinion is based on the fact that when it is shown to be an issue of tick noise and suspect rocker arm issue, it is usually just one or two and usually only on one bank. If it were a design or material failure issue, I would expect to see more of the rockers of a given engine have failed also.

That is why I suspect an issue at first manufacture assembly.

 

[DAVECS1]

My personal opinion it the components are just too small and in too small of space. Look at Honda, ford, toyota. Those heads are 20 to 30 percent larger and the spacing is huge. My guess is this helps with heat and oiling, and allows the high rpm abuse we all love.

 

[Deleted member 30519]

Does it sound like this? I've been trying to figure this out for over a year now. The dealership couldn't recreate the sound as it only happens once in a while. I also have a 6spd and it happens at 3k rpm like you stated.

 

[DAVECS1]

Does it sound like this? I've been trying to figure this out for over a year now. The dealership couldn't recreate the sound as it only happens once in a while. I also have a 6spd and it happens at 3k rpm like you stated.

Yeah, it sounds very similar. It is very loud in the video, but that could be the phone.

If I go WOT a couple times now that I have this sound, my tune detects the misfire and altered airflow, throws a code, and avenger light, and then kills the timing and VVT for power.

On a stock truck it may just let it ride, not sure.

 

[Ball_Ze]

I'm thinking maybe it is a rocker that isn't engaging the locking pin.

We used a similar design at GM where the inner part of the rocker followed the low lift lobe and actuated the valve. While in this mode, the high lift (outer) part of the rocker floated free, riding on the HL lobe, but not being mechanically connected to the valve.
Our oil control valve would would push a locking pin to make the rocker solid and open the valve using the HL profile.

If the rocker isn't able to engage that pin, the rocker is stuck on the LL lobe and the HL part rides the HL lobe, yeah, I know I've said that already - but it's possible the rattling sound you're hearing is the free HL rocker bouncing off the HL lobes because the spring shown below (dark blue) can only hold it on the profile to a certain RPM - or maybe the spring is broke.

 

[Hootbro]

I'm thinking maybe it is a rocker that isn't engaging the locking pin.

We used a similar design at GM where the inner part of the rocker followed the low lift lobe and actuated the valve. While in this mode, the high lift (outer) part of the rocker floated free, riding on the HL lobe, but not being mechanically connected to the valve.
Our oil control valve would would push a locking pin to make the rocker solid and open the valve using the HL profile.

If the rocker isn't able to engage that pin, the rocker is stuck on the LL lobe and the HL part rides the HL lobe, yeah, I know I've said that already - but it's possible the rattling sound you're hearing is the free HL rocker bouncing off the HL lobes because the spring shown below (dark blue) can only hold it on the profile to a certain RPM - or maybe the spring is broke.

You talking about the lifter floating at high RPM due to a bad spring?

 

[Ball_Ze]

You talking about the lifter floating at high RPM due to a bad spring?

Precisely - a bad spring -OR- the oil pressure isn't engaging the locking pin and the spring is being overpowered. I can't remember the exact RPM - but our rockers (made by Ina and not Delphi) I think started to jump off the profile around 3K or 4K RPM.

 

[DAVECS1]

Here this may help, I posted this in my other thread. ball_ze is on point.

https://www.jeepgladiatorforum.com/...ad-of-a-roots-supercharger.54832/#post-898376

 

[NachoRuby]

Does it sound like this? I've been trying to figure this out for over a year now. The dealership couldn't recreate the sound as it only happens once in a while. I also have a 6spd and it happens at 3k rpm like you stated.

I was getting this sound too, as you know. I haven't heard it in about a month. Same story, dealership can't replicate, because it doesn't do it often or all the time. They mentioned it might be a problem with the VVL setup, where it's stuck in a low rpm setting at high rpms. It sounds like a rattle, coming from the hood or dash. They adjusted my hood, but I'm not convinced that was the issue. It hasn't done it since. But it doesn't happen all the time anyway, so I'm not sure. I wish it would present itself prominently, so I could get a warranty repair, if it's the rockers.

 

[DAVECS1]

Well if the VVL solenoid gets dirty and will not close all the way. I could see it doing it, intermittently. Then it gets flushed and next time the oil gets shut off like it is suppose to.

I was hoping to flush my solenoids out with a couple RPM blasts but that just alerted me to the fact something is in gact more wrong.

 

[Deleted member 30519]

I was getting this sound too, as you know. I haven't heard it in about a month. Same story, dealership can't replicate, because it doesn't do it often or all the time. They mentioned it might be a problem with the VVL setup, where it's stuck in a low rpm setting at high rpms. It sounds like a rattle, coming from the hood or dash. They adjusted my hood, but I'm not convinced that was the issue. It hasn't done it since. But it doesn't happen all the time anyway, so I'm not sure. I wish it would present itself prominently, so I could get a warranty repair, if it's the rockers.

I was going to text send you a DM about this thread but then I saw you liked my post lol. I'm glad you haven't heard it yet since they adjusted the hood. Let me know if anything changes. I feel like at least we are gaining some ground since a lot of people are having the same issues. I remember back when I posted that YouTube video nobody knew what the heck I was talking about.

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