Hi again. There's this sound that comes from around my valve covers on my 5.2, pretty much throughout the rev range and primarily on the passenger side, that has been here since I installed this engine. The 3.9L I had before had the same sound, even in the same place. But with the 3.9, I blamed it on the lifters and moved on, because I didn't want to tear down that engine. But now with my 5.2, I previously installed all new lifters, but it makes the same sound that my 3.9 made. It doesn't sound like a typical valve tap, and my best guess is that the rocker arms are worn down, and just got a little noisy. Hopefully you can hear it in this video
It didn't seem like it was louder when I took the oil cap off, but does anyone recognize or know what this is? Is there any chance that it's something else, like the valve guides? I made sure my header bolts were tights, and I don't see any exhaust leaks. Also, last time I had the valve covers off, all of the rockers had similar amounts of oil on them, so I don't think it's an oiling issue.

I wish I got a photo of the rocker arms when I had them out, but they had a brown/brass-looking spot on the rocker where it rides on the pedestal, could that be it? I don't know what to look for on rockers. If that's a possibility, I could pull one out and post a photo. Thanks.

 

You sure what you're hearing isn't the PCV valve rattling?

Quick way to test: Pull the valve up, and plug the end with your thumb, see if the noise goes away.

RwP

 

Thanks for the quick reply. I did try that, but it didn't change anything. The noise is on the driver side too, just not as loud, and only above one or two of the cylinders towards the front it seems like. Passenger side, it sounds like it's above all of them.

 

Pull the passenger side valve cover, and wiggle stuff. See if anything interesting presents itself.

 

Yeah, I could try that. I did do that a while back, and re-torqued all of the bolts (they were fine) and spun the pushrods with my fingers. They spun smooth, but had some consistent resistance as I'd expect. None of the rockers had play in them or anything. All of the valve retainer locks were there, although I'd expect a much more obvious sign that something is wrong if one went missing. Wouldn't hurt to check again, but it seems like the sound is the same as it was back when I checked that stuff. I think I have some spare rockers sitting somewhere from an engine I tore down after it blew up. Previous owner drove it low on oil, and it threw a couple rods... If those rockers don't look too bad, maybe I'll throw them on and see if anything changes. I guess I'm still caught up on those, but are rockers wearing out not too common on these engines?

 

Not too common, no, although they can if the oiling wasn't kept up on them.

RwP

 

I don't think rockers are the problem..... they would have to wear a LOT to get enough clearance to start makin' noise. Usually, it's the lifters that are the issue...... but, I really wouldn't expect that on a new motor..... Is there any warranty on the motor? Have you had a chat with them yet?

 

It does not sound like a rocker.

It sounds like something is touching something. Maybe torque converter bolts, they sound like a spun bearing when they come loose. Can be a lot of things.

How is oil pressure? It does sound like it has none.

 

It's a manual transmission, but I guess it's possible that the sound is coming from it. The tranny is pretty noisy when cruising down the road, I never thought that it could be heard from there. Although, I guess I could depress the clutch, pop it in gear, and see if I can still hear it when I rev it. Oil pressure is 35-40 PSI hot idle, and 60-70+ at cruising RPM, so I'm not too worried about any of the major engine components.

 

Tried the transmission thing I thought of, by holding the clutch in, putting it in gear so the entire transmission is stationary, and then listening. Still made the noise. I decided to pull a valve cover and remove a rocker to show you guys what I'm seeing here.

This is one of my rocker arms:


And the pedestal:



Is it normal for them to look like that?




I have a couple spare ones from a different engine, roughly the same mileage (as far as I know), and they look like this:

Pedestal from other engine:



Upon comparing the two, this is why I kept thinking rocker arms. Is there a reason they look different?