When I start the engine it takes about 5 sec. to bring up oil pressure to a decent level (3-4 bar when cold).

Never really measured the time before but I have the feeling this is a new symptom. All my other cars I had (non-Morgans) were much faster to bring pressure up, usually already during cranking.

Yes, there is enough oil in the sump and the delay varies only a litte if the car stood for a week or a minute.

Should I replace the oil pump or is there anything else preventing pressure coming up immediately ? (48k Miles on the clock)

Any hints/ideas much appreciated !

Peter