High oil pressure guage

I have an 89 LaSabre. Under hard exceleration as in merging into traffic, emergency exceleration, or climbing hills the 'oil pressure guage' jumps to 80 psi and stays there until I let off the gas. If I let off the gas and the transmission changes gear the pressure goes back to normal (45-50). The indicator needle will 'peek' for a second then has a stuttering motion until I let off the gas and it changes gears. There is NO preformance change. She gets 26mpg city and 30 hyw. She has 184,000 miles with new alternator, water pump, fuel and transmission filters and valve cover gaskets. Regular oil changes. Other than the guage problem she runs smooth as new. Any idea what is causing the guage to 'peek and stutter'

You should expect the oil pressure to increase with the rpm. It uses a highly efficient ge-rotor pump, so it will put out a high pressure at those rpm. As for the needle doing the stuttering, that might be contributed to the oil pressure sensor. As long as you don't suddenly lose all oil pressure, you should be okay.

I have a '90 Lesabre that's doing the same thing. You need to replace the oil pressure sender which is mounted on top of the oil filter assembly bracket. A little difficult to reach, but should solve the problem