lately i noticed that my oil pressure has crept up on start up. It used to run up to 65 on start up with 15-40w. I switched to 5-40 synthetic and also replaced my oil cooler and lines. After doing that I noticed that the pressure on start up went up to near 80. Since I did this in late fall, I assumed it was due to cold weather. Now that it's warmer it hasn't changed. I cleaned all my grounds, replaced my ops with an ac delco one. After the engine warms up the pressure goes down to normal running about 50 -55 at high idle and down to 15-20 at idle. Is this something to check into or consider it normal?