EOT all over the place

[jimmyv13]

On a cold start, the ECT and EOT are within 1-2 degrees. As the ECT warms up, so does the EOT, just a little behind, 10-15 degrees. As the ECT gets to 190ish, lt levels off and the EOT sometimes gets to 190 then falls off to 170 or low 180's.

I have suspicion that my oil temp sender is bad, but the EOT and ECT are within 1-2 degrees on a cold start. Could the sender be bad still even though it starts out in spec?

[timfast77]

check sensor for crud it will act as an insulator for the sensor making it react slowly change oil
water/fuel in oil?
does it still happen after a long drive?(ect over 200*)

[f-250_LARIAT-2000]

subscribed, having same problem with mine.

[jimmyv13]

Originally Posted by timfast77

check sensor for crud it will act as an insulator for the sensor making it react slowly change oil
water/fuel in oil?
does it still happen after a long drive?(ect over 200*)

I am coming up on an oil change...what's the proper method to check for fuel/water in the oil?

I don't drive very long to work, 20-25 minutes. I may get a chance to get out this weekend for a run to my brother in law's which is 140 miles away.

[timfast77]

you can smell the dipstick or in the fill cap for fuel and look for creamy residue on cap if water, the best way is to have analisis somewere.
i would suspect both to be present in your oil as it doesnt get hot long enough to boil off water and short runs dilute with fuel

[jimmyv13]

I had the truck running for over 4 hours yesterday without shutting it down. ECT was 193-199 and EOT got up to meet the ECT once in a while, but never went higher than the ECT.

[timfast77]

did you check for dirty sensor first?

[jimmyv13]

No, I left work(no tools) and drove around with my 3 year old looking at new vehicles with the wife. I left it idling for 10-15 minutes multiple times.

I know I have a a couple of issues going on...I recently did an EGR delete and the occassional mosquito fogging has subsided. The EOT was jumping prior to this. I noticed a small amount of foam floating in the degas when I stopped to fuel up yesterday. This truck is fairly new to me, I've owned it less than a year, so I have no idea what the PO maintenance schedule was like.