No oil to top of engine, but no low pressure warning

[dhollow2]

After replacing the PCV hoses and doing a glove test to check the crankcase pressure I noticed that there didn't seem to be much oil squirting onto the cam lobes as seen through the oil fill opening. Even though the amount of oil flowing was less than I remembered seeing before, there seemed to be adequate oil on and around the cam shaft. This was about 100 miles ago. This past weekend I checked it again and no oil at all was flowing from the supply ports.

Here's what I know:
- 2001 V70 T5 with 150k miles. I've owned it from new.
- No low oil pressure warning.
- Very clean engine. All PCV openings were completely open when I changed the hoses. Oil pan seals were replaced 8,000 miles ago and the pan was very clean.
- Last oil/filter change 250 miles ago. I'm fastidious about maintenance and only use Mobil1 5W-30 oil. I pulled the filter yesterday to check for an issue there and it is fine.
- The valve train doesn't seem to be any noisier than usual.

I'm going to check the oil pressure with a gauge tonight but I haven't seen any mention of a sending unit that failed reporting ok pressure when it was low. Any failures I've read about indicate that they fail reporting low pressure. I'm not sure where to look next. I can't believe the oil passages could be clogged given how clean the engine is and always using M1 with regular oil changes.

Any ideas from the community? What else should I look at if the pressure checks out OK?

[oragex]

If there was not enough oil on the lobes, it will show quite some wear.. it is not a known problem, especially given a 1 owner car regularly serviced with synthetic. I'm curious about other opinions. Were all PCV hoses connected the right way?

[dhollow2]

I'm sure all of the PCV hoses are connected properly and I upgraded the banjo bolt at the intake manifold to the new design with the check valve. The glove test shows negative pressure at the oil fill port. I checked the oil pressure with a gauge this evening and read 70 PSI at cold idle and 86 PSI at about 2,500 RPM. The needle was steady without oscillation. I haven't been able to find the oil pressure specification yet but the measured pressures seem reasonable. I'm reluctant to let it run very long so I didn't check to see if it changed when the engine warmed up.

I think I was fortunate and caught the issue as it was starting so I don't think I've driven it dry very much. Here's a picture of the cam lobes visible through the oil fill port. It looks like there are some light scratches.

I'm not clear on where the oil sender port falls in the oil path so I'm struggling to diagnose where the problem might be. After the filter and cooler? Could the failure of any of the oil sump o-rings cause a symptom like this? I remember when I replaced them that the o-ring at the cooler end of the line from the oil filter housing to the cooler wasn't as thick as the original one. That line bolts into place and it looked like it sealed sufficiently but I guess it could have developed a leak and dump some of the oil back into the sump. That might make sense if the pressure is read before the cooler, but I would think it would be after the cooler.

I also tried adding oil to a little above the full mark on the dip stick. It made no difference.

So far I'm stumped...