Or more to the point, the lack of it. Not by choice, but I did a ten mile run up the motorway the other day. When I came off I had to stop, as I had a traffic light against me, and I noticed the oil pressure drop down to zero, or maybe +5. I revved the engine to see if it recovered any and it did, a bit. When I got moving again it went back up to 40 (ish).
Is this something that I should get investigated or is it something to associate with old jeeps?
The engine was professionally rebuilt a couple of years ago, maybe 2000 miles?