I have a 08 F350 SD with 110,000 miles. I change the motor oil between 3000 & 3500 miles. I'm running KEM tunes with a K&S tuner. Driving yesterday I noticed the oil temp slightly unstable and ranging from 203 - 213 deg. For the past several years this truck never went over 203 deg. Is this a sign the oil cooler is going bad? and if so what's involved in replacing the cooler. Thanks in advance.

 

Did your coolant temps rise as well? Where u towing or working the truck harder than usual? The delta or difference between the oil and coolant temp is important if they both rose and are within 15* it's not critical. I would def keep an eye on it since it's out of the ordinary.

 

typically i run the truck around 75 - 80 mph. I was not towing which usually will raise it up to 205*. the coolant temp was normal and the outside temp was 78 - 81*