Hi guys, we have a cessna 188 with too hot oil, engine temp oil 220 and 240 F.
We check galleries, oil, filter, change radiator and new vernatherm.
We believe that the EI oil press and temperature instrument is working well because increasing the temperature gradually lowers the oil pressure.
this happened after changing the rings and valves in a top overhaul what was not touched was the oil part.
We doubt in some deflectors that were built new that is the problem.
what do you think?

First look in the POH and see what the max oil temp can be. I would expect temp to be up firs 10 hours or so of break-in. Do you have pics of the changes made?
DENNY

Your problem is more than likely glazed cylinders. We had a Cherokee 6 years ago that the boss purchased back east with a “fresh” backyard rebuild. It was running hot by the time it got to Idaho and kept getting worse. We did all the usual stuff that sounds like you did, by the time it had around 25 SMOH you couldn’t get it onto the downwind leg before the gauge was pegged. Anyway after screwing around with everything we finally pulled the jugs, sent them to a shop and had them checked, re-honed and ringed. Ran like a top after we put it back together. If you have the tools and know-how you could hone them yourself and re-ring it. Just make sure you don’t baby it after you get it back together, it needs the high MP to seat the rings proper. Good luck.