After consulting my Bentley manual and various discussions on the internet I decided on a two stage approach to cleaning out my oil separator. Step one consisted of gently tapping around the outside with a screwdriver. This immediately produced results. All that dried up carbon and oil mixture stuck to the inside began to come apart and flake off. Shaking the separator resulted in a shower of dirt and grit from the bottom ports.
After a few rounds of tapping when no appreciable amount of dirt was coming out I then switched to what the Bentley manual suggested for cleaning – mineral spirits. Wearing rubber gloves, I used my fingers to plug the ports, poured in the spirits, and gave it all a vigorous shake. I did this several times until I felt the resulting runoff was as clean as it was going to get. I then used mineral spirits to clean the outside too.
Tellingly, the two most narrow ports, which had quite a bit of buildup in them, were now all clear. I think this will go a long way towards keeping PCV working as it should. There was one casualty, though. The o-ring that helps seal the connection between the separator and the block either broke when I took it out or was already broken before.
I’ve ordered a replacement but it’s not due to come until Monday. Before then I’ll probably clean up the part of the block where the separator attaches. That’ll just be a simple degreaser and brush job.