Jeremy, I remember a bloke that had a similar problem to yourself (he was changing the oil and left it to drain overnight, with resulting loss of pressure), to get the pressure back he filled the sump with oil till it came out of the dipstick hole, then cranked it on the starter motor for a minute or two, and normal service was resumed.ie full oil pressure. and remember to drain the sump back to the level before starting,
DB
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