My brother has a 2002 S60, 2.4Twith 90k, after driving awhile (to operating temp.) the oil light comes on and the text area reads "No Oil Pressure". I installed a new oil pressure switch but it still does the same thing. This morning, I put a mechanical gauge on it and it had 60 psi. at idle. After warming up awhile, it droped to 30psi. At operating temp. at 50 mph. it has 50 psi. the lowest I saw it was 25 psi at hot idle. To us, it seems it must be electrical. Any help would be great.

Thanks, Bill

 

I doubt it is electrical. I will bet you need to drop the oil pan and replace the pickup tube seal and seals between the oil pan and block. There is also a crossover pipe in the pan from the oil cooler to the filter that goes bad.