oil pressure problem

[turbo2nr]

so driving today seen the oil pressure gauge was bouncing from 40-60psi traveling in 5th @60mph..

i try to get on it to give it more oil pressure but it doesn't go past 60psi. and it still bounces from 40-60psi.

checked my oil b/c im due for a oil change.. turns out i was low, put in 1qt. and started the car up. the oil pressure seemed fine. reved it, oil pressure when to over 80psi. and it was stable.

drove for 1/2 hr mixed driving, and it started to do it again.. bouncing form 40-60psi..

im thinking it may be a spun bearing.. any other reason?

btw the gauges are defi. so is it a possibility that maybe the sending unit or something is bad? but i only does it some times.. and when the car is idling. its at 20psi stable oil pressure..

[kpodj61240]

my gauge got moisture inside and did the same thing.