Oil cooler cover

What tempeture can you cover your oil cooler? i think about 40 deg .

If the temperature is going to stay below about 40, you should be good. Even then, though, a long climb to altitude or a higher altitude operation (DA) may cause you to wish you'd waited.

Up here, when it gets below 30, I put a cover on, cause its' going to stay below 30 no matter what you do.


MTV

When covering the oil cooler inlet at 40 degrees OAT with a 108hp engine, it still takes quite some time for the oil temperature to rise to the recommended 180 degrees or so (to evaporate moisture). I suspect there are many variables, such as engine size and condition, oil cooler / duct installation, flying style, etc. Also, who is ever real sure of the temp gauge accuracy?