High oil temp reading

[William Mattson]

I still have lots of questions.

My 250 has been consistent giving me a 200 deg oil temp for awhile now. Sometime during the hot summer it changed to 220 and I thought it was the warm weather. I flew today just to check it. After landing I put a temp probe down the dip stick tube. I got a reading 20 degrees below the guage.

Questions. Is that a good place to compare temps? How can I tell if it's the probe or the guage? Is 200 degrees too hot?

Thank you,

Bill

[Clarence Beintema]

Hi Bill,

In the shop we remove the sensor from the oil filter adapter, fashion an extension wire and attach it to the airframe wire, connect a ground wire to the mounting threads and place it in boiling water then read the gauge to see if it agrees with the flight condition.

Clarence

[William Mattson]

Still working on this issue. The gauge reads accurate only when the alternator is off. I had the Alternator overhauled last year, but still was unhappy so I replaced it with an Air power at this year's annual. It reads approx. 30 degrees high when the alt field is charged. I'm not sweating this problem as I know it is a gauge problem not an engine problem.

Any suggestions?

[Chip Sylverne]

I think Lyc recommends ideal oil temps in cruise between 185 and 210, with max redline continuos at 245, so your temps don't seem too out of line. The benefit would be the condensate water will get boiled out. Keep an eye on your oil pressure. If it remains above 25 psi at hot idle, you're probably OK.

Chased a high oil temp situation on my 250, so I feel your pain.