Has something changed? Did you have the engine out for service and and now oil temps are an issue- the rag/paper towel in the fan (or Alan's rag left on top of the cylinders- that must have been a fun 1 to track down!) can drive you nuts trying to figure out what's going on. You said "the engine bay is all sealed up"- what's the airflow into the engine compartment like? An engine starved for air will overheat like there's no tomorrow. Put a remote thermometer in the engine compartment; anything more than a few degrees above ambient will tell you there is an airflow issue. A simple test- drive around until oil temp gets almost to the point of being unreasonable, stop and prop the engine lid partly open and continue on and note the result. Lower temps means you need to get more air to the engine. A member (can't remember who) did this with a pool noodle a few years ago, discovering that even on a short drive down to the beach his engine could be running cooler- what will happen at continual highway speeds?
As Carey suggested- look for the root cause.