For the past 6 months my tbss has had in between 25 and 30 psi of oil pressure at hot idle. It has 40 psi on cold start up. Driving it has a little over 40 and on the highway it has right under 40. Is it normal?
My best guess is the oil pump & spring could be worn if the pressure readings are correct. IMO the stock gauge isn’t a true reading (more of an “indicator”). Stock oil pump have a stamped steel backing plate while aftermarket pumps, such as melling have a cast iron one (stiffer).
Nothing wrong with those numbers. Now if you drop down to low teens at hot idle then start inspecting thing's. Everyone said it was fine and normal on mine and when I wasn't satisfied I pulled the oil pan and it was full of bearing material.
#2 rod had spun a bearing and trashed the rod and scored the crank. Never knocked just low oil pressure at idle, still had over 30 at 2k while driving.
When I'm running my torgue app on my phone my trailblazer is running hot at idle between 32-36. When driving it will go up to 42-44. The gauge on my dash will just go below 40 when hot and will be at 40 driving when hot. That's a normal range by sounds of what your saying.