M20J Low Oil Temp

[unicom]

Hi all,

As winter is settling down, I have noticed that my engine oil temperature in cruise is getting a bit low... I would like to check with you what kind of readings you get from you aircraft.

MP: 23'

RPM: 2300'

Altitude: 2500'

OAT: 48°F

AeroShell W100Plus

Oil Temp: steady 166°F

Oil Press: In the green band but rather low

How does that sound ?

Cheers,

Philippe

1980 M20J

[dooleyp]

At that low a power setting, and this time of year, that sounds about right.  I usually cruise a little higher (7-9) in my '88 J model, but the numbers look very similar.  I like my oil temp to get above 170 if possible, and this will typically happen running 2300 RPM and 24 inches of manifold.  As many will tell you, you can run at higher power settings, and the oil temp will increase.  There are those who say that you should run the oil temp to about 180 degrees for an hour to remove all the moist contaminants from the oil, thereby prolonging the life of your engine by reducing corrosion possibilities.

[orionflt]

The fact that you are running such a low temp with low oil pressure is a concern to me, if your oil temp increases your pressure is going to drop more. I would double check to see if your oil temp sensor is working properly, and if it is I would look at bumping up my oil pressure a bit.

[unicom]

Tanks Dooleyp and Orionflt for your answers. I have tried to run the engine at a higher power setting but the temperature still looks pretty cold as I can't even manage to reach mid-green band !!!

Temp probs are working fine as I have a double reading from the EDM700 and the aircraft gauge giving the same temperature.

After discussing with a mechanic, he believes that the Lycoming Vernatherm Valve could be faulty forcing the oil to pass through the oil cooler even the oil temp is cold.

Any thoughts ?

[jetdriven]

It's normal on ours to do that and that's two different engines. I think it's a combination of cold OAT and a huge oil cooler. That and the gauge measures oil temp after the cooler I think.

You could try taping 1/3rd of the fin area on the cooler wit aluminum tape like the Bonanza guys do.