I managed to find some time today to do the oil pressure check.
Armed with my own "special tool" I plumbed the oil pressure gauge into the feed pipe for the turbo and started the engine. As I had to adapt my adapter because the gauge wouldn't go in due to the oil drain pipe I modified it with a 90 degree angle piece, lined it up for the gauge to be connected and started the car. There was a small leak, but with 3 joints I decided to live with it.
Results as follows:
Startup, fast idle, 3.5bar
4 minutes, idle, 2.0 bar, water on first mark
10minutes, idle, 1.5bar, water on the 1/4mark - this told me that the oil was probably somewhere around the 70 degree mark, time for a higher speed reading.
I took the car up to 2000 rpm. The gauge showed 4.2 bar before the rubber hose on the gauge separated from the screw fitting, depositing oil liberally into the tray,onto the drive and onto my little helper
(At least she got the reading for me before going indoors to get cleaned up)
According to WIS oil pressures are to be checked at 105 degrees and idle should be min 0.55 bar, at 2000 rpm 2.5 bar with the pressure relief valve starting to open at 3.8 bar.
Those readings are not conclusive as I was nowhere near the required oil temperature, but I think they look good, or perhaps at least they do not look bad which is making me think the strainer is not sludged up.
While doing the test I could hear a whining sound. Remembering that a whining sound from a cold 9-5 engine is indicative of a blocked strainer I got my stethoscope out. There was no noise from the sump but the filter was undoubtedly the source of the high pitched sound.
The filter is a "Borg and Beck". Now I thought they made clutches, not oil filters.
Any views on their quality - I might just bang a new one anyway