What is the acceptable temp difference between the oil and water? Ford at one time said 10 degrees. After the latest flash I understand is was reduce to 5 before the CEL comes on. What are the temps difference others are seeing?

 

I have seen a difference of as much as 7 degrees between ECT and EOT on my Dashdaq, but usually the diffference is about 4 or 5 degrees. Never any CEL from that.

 

The new 11B23 reprogram uploades a ECT/EOT monitoring system. The temp diff differs depending on load. DTC p012F appears and wrench light will illuminate when pcm monitor witnesses a fualt. If cooling system integrity in good replace oil cooler. After relacing a oil cooler i have seen a 7 degree diff after driving it like i stole it.

 

My understanding is that a 15 degree difference indicates a failed oil cooler. Mine varies, with the highest difference having been 9 degrees.

 

Biggest difference ive seen is 6 degrees. ECT 195, EOT 201

 

Under what conditions? Just cruising down the highway at 65 unloaded and with little load on the engine, around 5 deg. generally. Hook up 17,000 lbs of camper, hit the hills, and the spread gets bigger.

What exactly are the limits, under what conditions, and when exceeded what do they signify?

The old testing procedure for failed thermostats stated limits for an unloaded cruising condition. Somthing about an 8 deg spread if I recall, and it mentioned a steady fluxuation in temperature on one of the readings. What if you have a larger spread but no fluxuation? How about the reverse? What are the limits when hauling a heavy load, or are the limits and conditions stated above the only ones that apply?

When hauling I've had larger spreads, up to 15 deg, but generally when pulling hills and the spread shrinks again when the engine load goes down. In this case I violate the temp spread indicated in the TSB, but not the steady fluxuation.

How about it you Master Technicians, what's the scoop?

 

are you a diesel mechanic . how many oil coolers have ya changed? dealer said my 08 f350 had a 38 degree differential and needed oil cooler about 3 grand to replace, does that sound about right

 

I just got back from a round trip to Reno NV from Sacramento. Ambient temp 85. Starting at 25ft elevation, over Donnar Pass 7200ft elevation. Pulling a 9600lb 5ver. Highest pyro temp 975. Engine oil temp 212, coolant temp 219. Speed never dropped below 53mph. Guess I just answered my own question. Manual trans, no tow haul mode.