Camshaft - Cyl 3 IN, what would cause this?

[pampadori]

Background - rebuilt engine 1000 miles ago.
Noise heard, sounded similar to exhaust leak mixed with loose valve adjustment. Louder at 50% throttle. Louder after engine full temp.

Checked head stud torque, adj valves, looked for exhaust leaks - all in spec.

Noticed Cyl 3 int cam lobe looks "different".
Rocker arm and shaft seem ok to me but not that experienced.

What do the experts think about this brownish in color cam lobe? It feels rougher than the exh lobe next to it:
https://youtu.be/JKivcHusudc

Here is the removed rocker and shaft:
https://youtu.be/814hi1WQE6s

Is the cam toast? How about the rocker and shaft?
COuld this cause the noise I have been hearing?

[76FJ55]

At initial look I don't see any issues from the videos. Looks to me like you are comparing the lobe section of 1 vs the base circle of the other. I'd rotate the engine through and see what the other lobe section looks like for comparison. Looking at the rocker you can see the same color change on the pad th at contacts the cam. The area of shiny silver is the contact area, then you see the line where it turns dark which doesn't have contact.

Out of curiosity, what oil are you running?

[pampadori]

Thanks for the reply. I'm using VR1 20w50 now that I've got some mileage on the rebuild.

I've put the rocker back in (which is a PITA without having the other shafts out for cyl 2 and 1).

Still not sure what the source of my noise is however.

[76FJ55]

What work was done during the rebuild?

[mikedsilva]

Strange..
doesn't look like the cam lobe is making contact with the rocker does it.... the lobe next to it is nice and shiny but the one in question is all brown and "rough" looking...but that is probably the back side.
Can you rotate the motor a bit, and take another less shaky video, showing the offending lobe so we can see if it is making contact with the rocker?
Also, a pic of the valve and springs...

[Trackrash]

Your rocker looks good to me. You need to look at the top of the cam lobe.

I would CAREFULLY check to make sure all the cam squirter holes are clear. If there is a problem with debris in the cam oiling tube it will be around #3.

[76FJ55]

Had a valve seat drop on my brothers rebuilt 2.0 VW motor after a rebuild a decade or so ago. That made some odd random valve noise.
If they replaced the valve seats during head rework, you may want to look into that.

[pampadori]

top of the cam lobe looks fine. Nice polished reflection like the exhaust lobe. I'll check the oil tube again to make sure its clear.

[bpu699]

Just to exclude issues, anytime you hear odd noises take off the alternator and air conditioner belts and run the motor...

Many a time I heard odd noises and turned out to be the alternator or air conditioner...

Also, did you try one of those mechanics stethoscopes?

Good luck,

Bo