My EA81 on my Brat is fluctuating with its oil pressure. Goes down to almost nothing at times, then goes back up to about 3/4 on the gauge don't remember what # correlates with that.

 

Yes there is adequate oil in the crank case too.

 

Is this a tell tail sign of a failing oil pump?

Is that with a real oil gauge, or the stock subaru one? If it's the stock one, it's not really useful for much. Some of them read consistently, some don't... Sounds like yours doesn't. My GL probably has a short somewhere and my oil pressure depends on the humidity... lol

It is the stock one. Didn't do this before I changed the white plastic piece that holds the gauges.

 

wasn't working at all prior, cause I think I fried something in the original one

Is fairly normal to be low at idle as long as it comes up when reved if worried put a manual gauge on it to check exact psi

Oil pump is bullet proof might need some new orings