REFLECTOR:Oil Congealing Problems in Lines to Front Cooler
Sun, 30 Nov 2003 10:09:40 -0800

At 11:16 AM 11/30/03 -0600, you wrote:
>My oil temperature sensor is at the cooler, so if my lines were congealed, 
>I wouldn't know if the oil in the engine got too hot.  Of course if I see 
>my oil temp begin to creep up then I know I have some flow.  Isn't it 
>unlikely that the engine oil will get too hot when the air temperature is 
>so cold?

Not at all unlikely.  If there's no oil flow to the cooler, the only 
cooling is through the surface of the sump.  When I was considering a 
trans-atlantic flight I bought every book I could on the subject.  One 
pilot told of flying high, in *bitter* cold, and having his oil temps start 
shooting up.  He pulled back on power, slowly descended, babying the 
engine, when he got to a couple of thousand feet where the air was much 
warmer the oil temps quickly dropped.  It was so cold at altitude that even 
with the engine running the oil congealed in the cooler, at lower altitudes 
it was warm enough that the cooler "thawed" and flow was restored.  He 
should have blocked off part of his cooler before he left, the cooler was 
sized for climb in hot weather.

You might want to think about moving your temp sensor to the filter 
housing, it will give you a much more realistic picture of what's going on 
in the engine.