High initial oil pressure

[romair]

So recently my oil pressure has started acting up. There are some mild fluctuations, but what is unusual is high oil pressures upon initial start. This lasts for a while, and usually by the time I am ready for take up, they go back to normal. This is a new development (usually I see low oil pressures on startup, as the engine is making very little power). In flight the oil pressure is fairly steady, just around 67 psi, which is normal. Could this be the regulator? It is kinda strange to have it only on start up though. If it was winter, I would think it may have to do with the cold weather, but it has been really hot here in Texas lately.

Here is a video of what it does on start-up.

 

 

Thanks, 

Stefan, 1989 M20J