How do I check oil temp gauge on O-360

jd21476

jd21476

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jd21476
I flew my Piper Comanche 180 today but the oil temp never came up so I turned back. (Oil pressure was normal)

i want to know if its the sensor or the wiring or the gauge. How do I check these?
 
jd21476 said:
I flew my Piper Comanche 180 today but the oil temp never came up so I turned back. (Oil pressure was normal)

i want to know if its the sensor or the wiring or the gauge. How do I check these?
Click to expand...
boil the sender in oil, and compare with a candy thermometer. it should give a reading
 
Thats assuming I have the gauge hooked up to it. Is there a way to do it at home?
 
Like can I put a multimeter on one end while I boil it and get a reading?
 
jd21476 said:
Like can I put a multimeter on one end while I boil it and get a reading?
Click to expand...
My guess is if temp never came up after a 5 minutes, a run up and TO. You have an issue with the wiring. The sender is best tested installed and hooked up to the gauge IMHO. Analog senders do have a resistance range for different temperatures. You would need to pull up the specifications for the sender and preform the same test as if it were hooked up to the gauge. So just do as @Tom-D suggests.
edit: you will most likely need to run a separate ground wire when doing the test
 
So I did the boiling water and checked the resistance per the table I found on Aircraft Spruce and the sensor seems to be working
 
If it just came out of maintenance and the oil temp is dead, I'd go looking for a broken wire or terminal all along the routing of the lead, all the way from the sensor to the gauge itself, and check that the gauge's hot terminal is getting bus voltage, too. A mechanic might have bumped something and disturbed a connection.
 
I hooked the sensor up to the gauge and then grounded it and placed it in hot water. The gauge registered the correct temp. I then reinstalled the sensor, started the plane and let it get up to temp. It worked fine. Weird!
 
jd21476 said:
So I did the boiling water and checked the resistance per the table I found on Aircraft Spruce and the sensor seems to be working
Click to expand...

Bad connection or bit of corrosion probably, then, dislodged by removing and reconnecting. Not unlikely the problem will come back if there's still corrosion on the contacts.
 
DeOxit is a good contact cleaner, for solving problems with intermittent contact due to corrosion. It leaves no residue. Even without disassembling the contact, it can help. It works for me.

https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU/

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