High oil pressure
 

On Saturday evening the oil pressure gauge was off the top of the 10 bar limit for the first time. That was a cold start.

I drive the car daily and regularly see 8.5 bar when cold and then it settles down a bit when warm.

I drove the car for 2 hours in the morning and there was no problem so can anybody suggest what could be causing the change in pressure?

I have seen the same readings every time since Saturday for cold starts so think I should get it sorted!!

bttt

Also its a 2.5 cosworth block with GT35 rotated turbo and RCM oil pump if that helps

What grade oil are you using? Has it been unusually cold at night?

First suggestion my friend is to get the oil pressure checked with another gauge, it will eliminate the gauge as the source of your problems.
Always happy to help !

Silkolene Pro S 10 W 50. The same as has always been used in there and was recommended by Oilman.

It's been in there for about 1500 miles.

Not aware that it's been any colder recently than in March and also the first time it happened was about 8:30pm so shouldn't have been below about 8°C.

Cheers Martyn will see if I can sort something out quickly in time for the weekend to get another reading.

Just checked the oil and is is a bit overfilled but has been like that for the past 2 weeks and haven't topped it up. Not sure what could have changed.