Well I got another gauge to check out my oil pressure. At first I was very plesently surprised, I was getting about 25psi at idle and about 60psi by 2,750RPM. Slow but surly as the car warmed up the pressure dropped off. To the point it was 15psi at idle and a max of about 47psi. I am using Castrol GTX 20w50. Since this is a very new rebuild I am thinking it's the front cover o-ring (S4 engine). I am wondering if it could be anything other than that, like maybe the thermostat in the oil cooler. I know it's not the thermal pellat because I put in one of the replacements from Atkins in the front bolt. I am trying to find other options because I am having a hard time getting Corksport to call me back.

If it is the oring wouldn't the oil pressure problem be there the whole time, even when it's cold?

And I have a question about my gauge. I am using a mechanical pressure gauge. And to adapt it to the block I just took my stock oil pressure sensor and cut the top part of it off and tapped the octagonal(is that even a word) part. There is only a tiny hole in the part attched directly to the block and I was wondering if that was making the gauge read incorrectly.

 

most likely front cover o-ring

we have same problem on one of our 'test' cars, cold its getting some not perfect but good pressure and warmed hardly makes any....

its because of physics of oil, even in perfectly working car, u will notice pressure drop once u will heat up oil...on long high speed runs when oil cooler is not able to keep oil temps down, your oil pressure will start dropping as well....

other thing which does affect oil pressure and its ability to stay cool is dilutation by fuel (on fresh rebuilds, cars often flooded etc )

 

OK that is what I was afraid od. The car was flooded (to the point that the oil wreaked of gas and was noticably thin). And it was making great oil pressure. Then I put in 20w50 and the oil pressure when to ****.

 

with fuel in oil it gets worse not better

 

When I had the flooded gas I was getting about 35 psi at idle and 65 by 3000RPM. Then I switched to the 20w50 and drove it around after going about 6 miles I stopped to get gas. When I started the car I noticed that oil pressure was down quite a bit only 20psi and 45psi. It dropped to 15 by the time I got home.