Desert Rat
Well Known Member
I've had the oil temp gauge on my G3X red X a couple of times now.
The first time it happened was during a static run. The data file shows it X'ed out at 129 degrees. After I rolled it back into the hangar I powered back up and it was displaying normally. Due to the intermittent nature, I thought I probably had a bad crimp where I hooked the probe up to ships wiring FWF, so I replaced those spade connectors with D-sub pins in heat shrink and that seemed to cure the issue.
A couple of subsequent short engine runs to adjust stuff, including a full power static run to look at the prop pitch, no problems.
On my first flight, it red X'ed again, this time at 131 degrees and stayed off for the duration. 20 minutes or so after shutdown I turned the master on and it was up and displaying about 190 degrees, as one would expect.
Yesterday I verified the configuration was set for the right probe (UMA 1B3-2.5R) and that my gauge temp parameters were reasonably wide (40 degrees to 250 degrees).
Since that all looked good, I pulled the connector off the GEA24 and looked for a pushed back or badly crimped pin, but all appears good on that end as well.
At this point, it seems like the only thing it could be is either a broken/shorted wire deep in the guts of my EIS wire bundle or a bad probe.
Unless I magically fixed this by un-pinning/re-pinning the GEA24 connector, my next step would seem to be putting the probe in a pot of hot water and seeing if the resistance increases in a linear fashion as it heats up or if it suddenly gets screwy at some point.
So, after all this back story, I've got a couple of simple questions:
-has anybody had one of these probes fail out of the box? maybe with similar symptoms?
-is there any other likely cause for my symptoms that I haven't considered?
The first time it happened was during a static run. The data file shows it X'ed out at 129 degrees. After I rolled it back into the hangar I powered back up and it was displaying normally. Due to the intermittent nature, I thought I probably had a bad crimp where I hooked the probe up to ships wiring FWF, so I replaced those spade connectors with D-sub pins in heat shrink and that seemed to cure the issue.
A couple of subsequent short engine runs to adjust stuff, including a full power static run to look at the prop pitch, no problems.
On my first flight, it red X'ed again, this time at 131 degrees and stayed off for the duration. 20 minutes or so after shutdown I turned the master on and it was up and displaying about 190 degrees, as one would expect.
Yesterday I verified the configuration was set for the right probe (UMA 1B3-2.5R) and that my gauge temp parameters were reasonably wide (40 degrees to 250 degrees).
Since that all looked good, I pulled the connector off the GEA24 and looked for a pushed back or badly crimped pin, but all appears good on that end as well.
At this point, it seems like the only thing it could be is either a broken/shorted wire deep in the guts of my EIS wire bundle or a bad probe.
Unless I magically fixed this by un-pinning/re-pinning the GEA24 connector, my next step would seem to be putting the probe in a pot of hot water and seeing if the resistance increases in a linear fashion as it heats up or if it suddenly gets screwy at some point.
So, after all this back story, I've got a couple of simple questions:
-has anybody had one of these probes fail out of the box? maybe with similar symptoms?
-is there any other likely cause for my symptoms that I haven't considered?
. That does help me though, to know that the symptoms seem to fit a bad connector issue.
