[Puzzled in CA]

I have a 1969 Duetto that I am getting back on the road after sitting for years.
Changed the oil, before restarting the engine, and the oil pressure gauge now reads HIGH, very near the upper limit on the gauge (100PSI or better).

Any thoughts, anyone?

 

[John Brase]

Sounds pretty "Alfa-normal" to me. Every one I have had showed high oil pressure when first started from cold. Then at idle when hot you wonder where all that pressure went.

 

[ghnl]

If your car has an electrical sender/gauge the sender might be faulty. Confirm the readings with a mechanical gauge. It is normal for oil pressure to read high after a cold start (especially if you are using a 'thick' oil). But the pressure relief valve should open to bleed off any excess pressure.

 

[Alfajay]

I have a 1969 Duetto that I am getting back on the road after sitting for years. Changed the oil, before restarting the engine, and the oil pressure gauge now reads HIGH,

I agree with what ghnl said: could just be a faulty gauge. Checking with a mechanical gauge would be a good idea. However, I'm not sure I agree with John: if your gauge is accurate, and you really are getting oil pressure approaching 100 psi, then something is wrong.

The fact that this engine has been sitting for years is a red flag. The relief valve in the oil pump might be stuck. I recently helped a friend rebuild an engine that had been run regularly, but with a couple of missing crankshaft plugs - consequently, the oil pressure relief valve hadn't moved in a long time. The valve was quite stuck in its bore, preventing it from venting off excess pressure when the engine was cold.