Oil pressure is bouncy after new engine

[stuartrubin]

I recently had a new (new to me!) 2.0 L engine installed into my FIAT 124 Spider after the throw-out bearing broke and ruined the block of the original 1.8 L.

Engine, etc., are all working great now except for some anomalous behavior on the oil pressure gauge. The pressure appears to be very erratic, bouncing all over the place from low to high. Eventually when driving at normal speeds it settles down, then for no apparent reason, it occasionally acts up again.

The other gauges (i.e. fuel) seem fine.

Before I do anything radical, can anyone give me some ideas to check?

Thanks!

Stuart

[grasshopper]

Could be either a short in the wire that connects to the sending unit, or the sending unit is sketchy, or just a thought, have you put on Teflon tape to thread the sending unit on ? If so, it may not be making sufficient ground ?

[18Fiatsandcounting]

Grasshopper gave the exact answer that I would have given, and I'll just add that I doubt it's your actual oil pressure that is bouncing around that quickly, but rather an issue with the pressure sending unit or its electrical connections. If the oil pressure sending unit is original, it's a good idea to replace since these units tend to go goofy over time.

-Bryan