I am experiencing oil pressure anomalies on a totally reconditioned engine. On starting the engine the oil pressure climbs to around 70 psi then promptly drifts back down to zero after a few seconds (oil still cold). I have replaced the sender and then the gauge from a scrapped 1977 Mk2, both made no difference.
Next I replaced the whole filter head, as it occurred to me that the ‘blocked filter bypass’ was possibly coming into play - correct quality new filter and correct grade of oil is used - still the rise and immediate fall in pressure reading persists, regardless of the engine rpm. Throughout all the starting and stopping the engine sounds quiet and smooth, so it would seem that it is getting some oil.
Can anyone help please?