At one time my engine had excessively high oil pressure where it would blow oil out of the dip stick tube if the dip stick was not fully seated. I changed PCV valve and hoses and still high pressure. Finally i decided to rebuild the TBI unit and during the disassembly I discovered that the port on the TBI unit for the PCV valve was blocked with oil/carbon build up. Once the TBI was cleaned and re-installed the oil pressure was once again normal. Maybe this can help someone else with the same symptoms. In effect I had no crankcase ventilation.

 

The title is misleading as oil pressure was not the cause of the problem, rather, excessive crankcase pressure that was causing the oil to come out of the dip stick tube. As you have found, a plugged PCV vacuum line can cause this problem.

 

I was actually reading between 60-80 PSI on the dash gage with a plugged PCV system. It took a while to identify thereason for the high oil pressure gage reading. The oil gage pressure was a symptom along with blowing oil out of the dipstick tube. Having changed the PCV valve and hoses did not correct the problem.

 

it may have affected your oil sending unit try replacing it