Erratic oil temp

[RvAviator]

Got some strange oil temp readings last flight during descent. Oil temp in a few seconds rised to 340 F, then a short stop (2 s) of registration then a similar drop to more normal values. However indicated temp fluctuated rest of flight. All other engine parameters fully normal and stable during flight.
So, most probably probe failure or wiring. I tested pulling in all wires during a ground check, only normal indications.
Leaning to recrimp the connection from sender to harness to start with, but not easy to troubleshoot intermittent problems.

Seems after a search that there are a few who had same problem. Recrimping not solving the problem. So maybe best to order a new probe?
Probe is a Garmin UMA 1B3-2.5R, connected to G3X. Probe mounted on top of engine close to oil filter. IO-360-M1B.

 

[D-Dubya]

You're right that the first thing to check is a connection issue. If you've re-crimped the wires at the probe connection end (a poor connection here is typically the #1 issue), you could also check the wire routing and make sure there's not a rubbing or chafing issue somewhere that could be causing an intermittent issue. After that, it only leaves the connection where it goes into the D-sub at the Garmin box. If those pins are seated well, then it most likely points to a probe that's going bad.

 

[R&J Cosh]

Had a very similar experience with my 14a at around seven hundred hours. After checking the connections and re crimping the leads at the sender, same result. Replaced the sender and everything back to normal for the last hundred and fifty hours. Not the first to have to replace the sender, and surely not the last.
Juliette

 

[RvAviator]

That's for info and guidance!
See if I can get things done next week when I get to the hangar. The sender is not too expensive I believe.