40 psi with a warmed up engine sounds normal to me.
they warmed up with a healthy diet!
Warm front
When air is warmed, it expands and becomes less dense, causing it to rise. As it rises, it creates lower pressure at the surface. This is because there are fewer air molecules pressing down on a given area as the warmed air moves away.
It is normal for the oil pressure to drop some when warmed up.
oil pressure normally will go up and down with rms for the most part. when the motor is cold there is more oil pressure as the oil and motor get warmed up the oil thins out and the pressure goes down.
The warming air would expand and the tyre pressure would go up.
It is normal for the oil pressure to drop when the engine is warmed up and at an idle.
MY Mercruiser 502 8.2L V8 between 133-155 pounds pressure dry, not warmed up & throttle at idle instead of wide open throttle. I was comparing the difference between the cylinders seeing if anything was obvious bad... Warmed up... Open throttle valve will give you a higher reading.
It doesn't really come from anywhere. High pressure can form anywhere when air from aloft converges aloft and then is pushed downwards, compressed, and warmed. The air then divereges at ground level. Usually the air that has been compressed and warmed doesn't have any clouds because in the process of being warmed, clouds dissipate from the compressional warming. Hope this helped!
Probably needs a new Idle speed sensor
When the air in the atmosphere is unevenly warmed by the sun, it creates temperature and pressure differences, leading to the formation of wind currents. The warm air rises and the cooler air moves in to replace it, creating wind that flows from areas of high pressure to areas of low pressure. These differences in temperature and pressure drive the circulation of wind in the atmosphere.