LT35 (88) oil light at idle - why?

[feliciafunandLT]

Quick query - the oil light on my ancient LT35 (2.4 diesel) flashes when idling - it doesn't do it when the revs go up, when driving or when stood in traffic etc - just when ticking over on the drive. Its been doing it for five years now so I'm kinda guessing its not about to blow up or anything but to save me having another stand up argument about it I'd like some input from you knowledgeable types on here!
So far "man on the street" has told me "the big ends gone" (this being the stand-up-argument-man-in-the-street!) whereas my wise and knowledgeable local mechanic put it down to a sticky valve in the oil filter.
I've got a new oil filter that I could fit but I've just spent five days tinkering with other bits of the van so I'm not really interested in starting another job!

I know....I'm a bad person

Thanks all

[Alan02]

Faulty Oil Pressure Switch ? Change oil and filter if its overdue or had poor quality oil in. I`d go for the simple bit first!

[feliciafunandLT]

Ta!
I'll get my hands dirty at the weekend - got the filter, just need the will power!