History: oil pressure alarm intermitantly coming on. no change in engine noise or performance. gradually became worse. purchased new oil pressure switch (VW), fitted made no difference. Made fitting to enable measurement of oil pressure.

0.35bar (5psi) at idle and same when revved.
oil pressure switch switches between 0.75 and 1.05bar, hence alarm.
what should i look for now?
is 0.35bar enough?
could there be a relief valve stuck? or need adjusting?

any ideas?

okaruss