MatthiasArnold Posted February 3, 2021 Report Share Posted February 3, 2021 (edited) On one of my most recent flights with my O2 GX I observed fluctuating oil pressure indications. While around 60psi is the range that I normally expect during cruise in moderate (winterly) European weather conditions, the value dropped down to something around 48psi for some period of time and suddenly back to the 60ties range. Although still in the green arc I felt somehow alarmed. Analyzing the data of some previous flights with Savvy (the G1000 software update to 401.34 which includes data-logging was done in autumn 2020 ) I learned, that this behavior already existed in previous flights but got worse over time. Based on the signal's shape (sudden drop/recover, spikes) and my experience with a multitude of smaller electrical bugs with my aircraft, I decided to inspect & service wiring and especially connectors first (I found the MS topic Oil Pressure Transducer G1000 M20R the same evening after I visited the hangar ). I serviced the Kulite pressure sensor-connectors for MAP (APT-20G-1000-25A (0..25psi absolute)) and OP (APT-20G-1000-150G (0..150psi relative to ambient)) as well as the two larger connectors guiding the many different engine & airframe signals through the firewall to the GEA. Before doing a test flight I checked the validity / consistency of the GEA signals in service mode on the PFD (while still being on the ground) - looked good (please also note the hangar temperature of only 2°C - happy I have Reiff engine heaters installed). Analyzing the data of the 30min test flight showed spike-free smooth oil pressure signals which behave as the should behave: Basically a function of RPM (pump actuation) and oil temperature (oil viscosity). To keep a long story short: Lots of smaller electrical glitches in an "electrical" air plane like O2 GX, especially if it was rarely flown (in the couple of years before I purchased N913KS last summer it was only flown app 10h/a) - in my case glitch number four since I own the airplane (flap switches, GIA #2 <-> MFD, speed-brakes, OP sensor) Besides corrosion/oxidation of micro-switch contacts (flaps, speed-brakes) and connectors (OP sense, MFD/GIA) bad solder joints can be a major cause for electrical glitches (see topic Oil Pressure Transducer G1000 M20R as an example for the latter) Before throwing tons of monies on exchanging expensive/hard to source components it might be a good idea to start with inexpensive things like cleaning and servicing electrical connectors and contacts.. Best, Matthias Edited February 3, 2021 by MatthiasArnold Attached images 1 Quote Link to comment Share on other sites More sharing options...
1964-M20E Posted February 3, 2021 Report Share Posted February 3, 2021 it is possible to be the pressure sensing unit I had this happen to me years ago scared the SH&%$%^& out of me when it first happened a altitude and bitchin betty saying check engine oil pressure and temperature and red lights flashing. After changing the sensor the problem went away. 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted February 4, 2021 Report Share Posted February 4, 2021 Excellent pirep, Mathias! Great details. Fantastic shared experience all! Best regards, -a- Quote Link to comment Share on other sites More sharing options...
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