Oil pressure slow to rise when car first started.

[dnb]

The oil pressure gauge seemed to be very slow to climb to its normal position this morning. The pressure warning lamp also was much slower than usual to extinguish. Once the car has been started and thoroughly warmed up, everything is normal for the rest of the day even if it has cooled down while sat in the work carpark.

What could cause this? I very much doubt 2 separate systems could fail simultaniously (but it is a TVR after all...) so I am thinking of a worn oil pump or a leaky pressure bypass. But before I take everything apart, it would be nice to have an idea of what sort of thing goes wrong with very high mileage, (relatively) highly tuned Serp RV8s...

The engine isn't noticably noisier than normal, but it's hard to tell given the extreme quietness of the new exhaust And yes, I do keep the oil topped up before anyone asks

Thanks.

[HRG.]

A colder morning than of late? Does it rise at the normal rate once it's had a heat soak?

[LordGrover]

FWIW my bimmer does something not dissimilar. No oil pressure gauge, but about ten seconds after starting the oil level light comes on. It switches off again after another minute or so. I'm told it's a sticky sensor or something but nothing to worry about unless it remains on.

[dnb]

The sump is coming off to fix a leak shortly. Just need to get that S body out of the garage...

[Uncle Fester]

Mine recently did the opposite and gained pressure on the dashboard gauge although sticking a capillary gauge on confirmed it’s a false reading. I have a genuine 60lbs all the time but either high revs or a wide open throttle at low revs sees the reading go off scale high.

An earth fault seems the most likely suspect at the moment, which could affect more than one system. In my case the sidelights have started dimming in time to the flash of the indicators as well, reinforcing the suspicion.

[Hamburglar]

Could be a fragment of silicone gasket from the sump partially blocking the feed, thats always a popular one?