XUD Oil Light Slow to Go Out Cold

[Pug_XUD_KeenAmateur]

My oil light's taking too long to go out on cold start up and is accompanied sometimes, just as worryingly; by a slight 'ticking' which sounds like a slightly worn camshaft to me.

The old girl's far from in the first flush of youth (1996, 207k) but these engines don't generally suffer poor oil pressure and I'm fussy bout changing the oil (every 8k, £20 semi-synth); in fact, where my car's concerned I'm just plain fussy !

Is it worth me putting a flushing oil in the system a while; can it do any harm?
How many oil pressure sensors does my engine have, just the one near the filter?
I don't have a means of checking the oil pressure, is it worth getting a gauge?
I know that its an easy job to have the sump off these, but am not sure what I'd be achieving in doing so

What's my best first port of call?

In the meantime I'll deliberately crank her over before the glowplug light goes out, specially in summer so she don't start instantly

Thanks People !

NB: I've no reason to suspect any serious internal issues, no backpressure or bottom end noises and good performance for one of these (normally aspirated); not at this stage leastwise.

[spider]

Just the one pressure sensor near the filter. You could try replacing that although I've only seen them fail and be on all the time (rare though anyway)

My other initial thought is sludge build up in the pickup mesh area. If you pull the sump off its worth checking this, I'm not 100% sure how easy the mesh comes out though something tells me you can get it out without having to mess about with the oil pump and chain (a pain)

Flush, hmm well in theory yes but the downside is you may have it going around and it could then block something it should not.

They don't really rattle from the cam gear though.

Assume decent oil grade ? , I've always put 10/40 into the XUD/XUDT units.

EDIT... What car is it ? , reason for asking I think on a 306 with AC you have to take the PAS pump off as well (!) to get the sump out the way.

[Pug_XUD_KeenAmateur]

Thanks Andy, yes decent oil grade; Wilkinsons 10/40 Semi-Synth
Its a 405 with said Air-Con Pump on the ali sump with the fitting for it; very likely the same set up as the 306 you're referring to. Not the end of the world to remove with the sump; just an added pain.
Perhaps what I'll do is pop the Rocker Cover off first, which would benefit from a new Gasket anyway (small leak at Vacuum pump end) and if I find any appreciable amount of sludge in there I'll have the sump off at a later date
Comment much appreciated, thanks again