NW 1Z Engine: Damaged Camshaft Lobes

Hi,
Attached is a picture of a camshaft lobe from the intake side of my 1Z engine (cylinder 3, exhaust valve). The tip of the lobe has visible and palpable craters. The hydraulic lifter underneath feels rough when touched with a toothpick, is discolored brown, and definitely needs to be replaced. The other lobes look better, but also have individual craters.
The engine has a mileage of 425,000 km, and the valve lifters have approximately 200,000 km. The oil used previously was Castrol Magnatec 15-40 (or GTX3), and since the last oil change, it has been Magnatec 10-40 (all meeting the VW 50500 specification).
The question is whether the existing NW (presumably a piece of equipment) is still usable, or whether it will soon only ruin the new pistons.
hg
Herbert.

It's possible that the cam lobe, with its pitting marks at the top, could damage the lifters. If you plan to drive the car for a long time, it might be worth considering using a possibly used, but healthy, camshaft.

Quote:

It is possible that the cam, with its pitting marks at the top, could damage the hydro lifters

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, but 400,000 km is quite a distance . More modern designs sometimes don't even last half that long.

I would replace the NW if I continue to use it.

Install the used camshaft with the corresponding lifters, and continue with the crankshaft wear.

These are mileage figures that are normal for older VEP TDI models; owners of "modern TDI" cars can only dream of achieving the same.

The NW (presumably referring to a valve or component) and lifters have been removed. All the lifters show signs of wear with 200,000 km of mileage, including worn surfaces with craters, and some star-shaped wear patterns, suggesting they were not rotated evenly.
Die entsprechenden Nocken haben auf der Rückseite Riefen. Interessant sind Haarrisse an einigen Nocken quer zur Laufbahn. Does anyone know about this?
I already mentioned the craters at the peaks in the introduction.
The axial clearance of the NW is within the tolerance of approximately 0.08mm. All hydraulic components were easily rotatable within their respective bores.
Conclusion: Replace the water pump and hydraulic components with new ones. I'm avoiding used parts due to the time required to find them and the expected quality.
hg
Herbert.

The new camshaft and new lifters are ready. For comparison, I measured the height of the old and new camshaft lobes. The old lobes are, on average, 0.5 mm shorter, with one case being 1 mm shorter. Using a caliper, no difference could be measured in the base radius of the lobes.
A question - the surfaces of the cams and the cone of the new NW are not polished, but black (nitrided?). Does this need to be polished?
Sure, here's the translation:

"Best regards," or "Sincerely,".
Herbert.

I'm only familiar with issues related to the hydraulic units, but that's very rare. Perhaps there's a material defect, or maybe this particular hydraulic unit isn't being lubricated as well as the others?
An Audi 80 with a 1Z engine, with over 700,000 km, had all its internal components looking like new after a head gasket replacement, even though this company doesn't seem to be very precise about oil change intervals.