I have a Alfa Romeo 159 from 2008 with 1.8 GM petrol engine(F18D4 version). For more than 4 months the oil temperature raises more then normal when I go over 74 mph and gets to 130 (266 Fahrenheit ) and keeps getting to 140 (284 Fahrenheit ) if I keep accelerating. When I drive the car under 74 mph the oil temperature is normal.
The normal operating temperature(described by the producer) is 110 C degrees (230 Fahrenheit ) and in the past if I drove the car with 111 mph loaded with people and luggage the oil never reached more then 248 Fahrenheit .
The water temperature remains at 90 C degrees(194 degrees Fahrenheit ) like the producer says, the oil and filters are changed according to the producer specifications.
I went to a mechanic and he said to change the oil temperature sensor but he didn't even checked it.
What should I do?
Kind regards from Europe :)