Cm870 oil running hot

[Running rough]

Been noticing lately, oil will climb to 250 degrees Fahrenheit with out hardly worked engine, oil seems to heat up faster and takes longer to cool down, water temps are normal and don't climb to fast, anyone run into this issue and what is the most likely culprit, oil cooler?? I would like to get it fixed before I get a bad driver behind the wheel who doesn't moniter gauges and I will be faced with a wrecked engine and a big bill