2000 xj 4.0 151k on motor
was driving to work this morning and oil pressure spiked to 80 on the highway. Pulled over and turned it off, turned it back on and still at 80. Checked oil, oil was normal. Started it back up and now it’s showing regular pressure. Sound like a sending unit going bad?

 

Irratic readings- sounds like it.
Verification with a gauge is always best but if you do startups and they show high and then normal without anything done otherwise (like changing oil filters, any other works) , suggests a faulty unit unless proven otherwise I'd say.

Would also check its wiring. Wiggle it and see if that does anything on the gauge.

 

Wiring would make sense too, motor was replaced 1k ago before I bought it and already found a few issues with his wiring, like forgetting to put the ground for the DLC back onto the block lol I’ll check that tonight

 

Also have read your other thread-
Might want to check ALL grounds after that find...

 

Not a bad idea