Oil cooler going bad?

[Groundpounder1]

I've read multiple threads that say the ECT and EOT difference should not exceed 15*. Mine is usually good but today I was towing about 5000# on a long steep on ramp getting onto the freeway. I was closely monitoring my temps and the EOT climbed to around 220* while the ECT stayed just below or at 200*. I was towing the short trip (10 miles) with the SCT set on the mild street tune. Is this cause for concern?

Is it alright for the differences in temps to widen for short periods of time (accelerating up a long on ramp), as long as they get back together after a short time, and normally stay close together on normal daily driving?

If the oil cooler is going bad, how much does it cost to repair/replace? Could this mean that there's something else wrong with my truck as well or is it a stand alone problem that could cause other things to go wrong?

Or am I worried about nothing since it only did it that one time and is usually within the normal range?

[SteveBricks]

I wouldn't worry about it unless it showed that much of a difference during normal driving.

[TUCSON STROKER]

I just went through this 2 weeks ago. pulling my 5er up a small grade here in Tucson and noticed my EOT at 231 and my ECT at 208. called my buddy at my local ford dealer who is my repair guy and he said that it was my oil cooler being clogged. took it to him and he was rite. he just replaced my oil cooler maybe 3 months ago when he did my studs and EGR cooler delite. he said these things do go bad. thank god its all under warranty for me.

[paulpe99]

I replaced my oil cooler when the EOT was deviating by more than 15 degrees from the ECT. Especially while towing my 5th wheel. I thought it was just another bad fan clutch. But, no, the dealer confirmed the possibility that it was indeed the oil cooler. Apparently the on board computer doesn't compensate and engage sooner if the degree of separation exceeds 10 degrees. It only kicks in based on ECT. So, after getting the estimate from the dealer, I went and bought a new cooler online and installed it with the help of my son. We also bought a coolant filter kit and installed it ourselves. I definitely recommend the coolant filter kit. If the oil cooler goes out again, I'm going to look into a modified design cooler.

[Groundpounder1]

Well, I feel much better now. I loaded the 50hp tow tune (canned tunes SCTx3) and went on the same trip this afternoon. The temps stayed within 12* of each other the whole time and quickly got to within 5* once I got to the top of the hill and drove on level ground for a few miles. I was told that I could tow short distances on the mild street tune but I think that hill, combined with the street tune, drove up the boost which caused the oil to heat up quite a bit.

Those of you with the SCT, do you all use the tow-haul button on your shifter when you tow with the tow tune? Keep in mind that mine are the canned tunes. I tried it without the tow-haul feature and it did not feel like the tune adjusted the shift points or adjusted the torque converter so I kept the tow-haul button pressed.