Oil pressure off the scale

My oil pressure reading has always fluctuated somewhat (at least since I bought the aircraft at 26 hrs - now 50). Sometimes only a little, other times 10 - 15 psi but always in the green. About half an hour into last flight it started oscillating wildly and rapidly from around 40 psi upwards to off the scale. Got the the aural 'high oil pressure' warning. Throttled back to 5000 or just under and settled back to 'normal'. Increased revs again and all ok. Then during taxi it went berserk again. Pulled the cowl today and discovered I have the Honeywell sensor mounted on the engine. Have read all the previous posts discussing this issue - first thought: another Honeywell failure and time to move it to the firewall, but don't recall anybody describing this particular failure mode - most referred to low or zero indications. Could this be a wiring connection issue as previously described or air getting into the system? Or do I just replace and move? Any thoughts from the more experienced would be greatly appreciated.

Oil Pressure Failure?

Sounds like your oil pressure could possibly be failing.
Do you have the Honeywell transducer?

http://www.vansairforce.com/community/showthread.php?t=65042&highlight=honeywell

You can put a mechanical gauge in the oil line, but my guess is it is either a bad connection on a wire or the sender is going bad. Check the ground wires first. If you have another sender or access to one you can try that. I highly doubt you have a real engine oil pressure problem. They are very rare. 98% of the time it is the sender or a bad connection.

What oil pressure sending unit do you have?
VDO, Honeywell, Keller or Kavlico?

Thanks for the advice. It's a Honeywell sensor on the engine, so failure not surprising, it would seem. I have no doubt it is a sensor issue - can't see any way an oil pump could produce those results. Think I will relocate a new sensor to the fire wall. It seems the smartest thing to do but will check the wiring first.

Jack Moore

Last weekend I was on a cross country. During run up prior to returning the oil pressure fluctuated wildly for a second or two and then locked in solid at normal pressure (about 60 psi). No more issues in a the 4 hours and two flights since then.