If you have or are installing an aftermarket oil
temperature probe, then you and your mechanic should read this article to be
sure you don't end up with a catastrophic engine failure.
Read the full article
Below is a picture of where I placed my JPI oil temp probe
in my IO470L engines.
Many folks fret about their engine oil
temperature not reaching 180°F or higher to burn off moisture buildup
(I'm not one of these folks). I've operated my IO470-L engines for over
2000 hrs with JPI probes mounted in the front of the cases under the
prop and have always seen roughly 150-160°F in cruise throughout the
year. Occasionally, during summer ground ops in Texas and Florida I
would see 180-190°F.
I can't detect any negative issues
affecting my engines as a result of my operating parameters. I run
Aeroshell 100W, sans additives, year round and have Airwolf oil filter
adapters with spin on oil filters and change the oil and filters at
roughly 50-hour intervals.
Here is Michael Thompson's, of AVSTAR Aircraft in WA, take on oil temp through the Continental oil cooler design:
need to understand where the vernatherm is in the system. The oil has
to be hot enough, long enough, for the vernatherm to properly close; it
is at the outlet of the cooler. You are thinking it is at the inlet to
the cooler, like the thermostat of your car.
drawings, from the M-16 M&O, show the flow. As seen, the oil has to
be hot enough to get to the vernatherm spring to expand it and shut the
door (so to speak), but the spring is not in the direct flow of all the
oil until the door closes. A certain amount of oil by-passes to give
the oil cooler the non-congealing effect, and the oil would need to get
plenty hot enough to transfer enough heat (to the vernatherm) to shut
the cooler keeps the by-pass oil warmer, thus raises the temperature,
but it will never raise it above the temp the engine is making."
Below is a picture of an oil temp probe installation disaster on Paul V.'s Bonanza.
A precautionary landing when his alternator went off-line saved the day.