My 6 conversion…2.2 built on an original 916/6 case has been pretty darn reliable since its completion 2 years ago. The engine has less than 15K since it was rebuilt. At cold start up she fires right up and makes good oil pressure…will climb to almost 100 on the gauge when blipping the throttle. It has been really hot here in Central Florida over the last week…97 degrees everyday and it was to be no different today. My wife drove it to work this morning at about 7 am and temp was about 86 degrees outside…She called me when she got to work…and now I have some concerns… She was on the highway at speed 65mph for about 20 minutes in 5th gear. She noticed the temp had climbed to just below the red mark and the Druck Pressure gauge was at about 20. When she pulled into her parking spot put it in neutral and rev’d it up to just above 3300 rpm and the pressure gauge wouldn’t go above 20…She drove it home this afternoon and the outside temp was 96 degrees and she notice the same results. I snapped the pic in our garage a few minutes ago. What do you think it happening? Could it be an oil pressure relief valve not functioning properly ?

I think the oil is getting way too hot. Do you have a front mounted oil cooler?

I have basically the same motor as you. However, I have the original
gauges (and senders). Since you said this only started happening
recently, it is not likely a problem of gauge/sender matching though.

All I can say is that a 2.2L E-type motor does not need any additional
cooling over the stock cooler. All the things I was going to suggest
are not going to be applicable since you say you're getting low oil
pressure too.

I looked around more in the engine bay this evening. I noticed that the engine firewall sound pad (Lightweight silver foil type) had collapsed quite a bit and was resting around on the cooling fan. This could be the reason for sudden change in temps as air flow was interrupted. I will take the pad out completely and see if the temps subside. Please continue to chime on this in the meantime.

My 2.2 motor barely gets to 180, but I have a front mount cooler. After driving a while my oil pressure at idle drops to 20, but revving the engine does raise it up.

Holy Crap that's hot. If the gauge is accurate change your oil now. You likely saw 280 degrees or more!

Firewall could be part of the issue. If its coming apart in pieces, I'd find a bore scope to use and look under the shroud for debris.

Install a mechanical guage in the engine compartment to test.

Certainly it would be a good idea to verify the integrity of the gauge (put the sensor in boiling water to check), but that is pretty hot if correct. I'd agree on changing the oil. My 2.7 will run at 210 on a hot day while running for a while (again with a front mounted cooler), and the oil pressure will also run around 20 psi with increases with increased revs. That's running Kendall GT 20W-50 on an 85 degree day on an interstate.

Ok I got a chance to inspect things a little more today. I changed the oil and filter and then looked into the engine bay...the engine firewall sound deading pad had pulled away from the center keeper and the pad had collapsed around the fan. So, I removed the pad fired her up and went for a drive. Was out for 25 minutes running it pretty hard and all is well. Temps ran in normal range the gauge never reached the the halfway mark and pressure was good.