I've been trying to read and digest all of the threads on Oil and Coolant tempatures and am still confused and concerned.

2006 6.0, CCSB SRW with 156,7xx miles. Regular service with Ford Recomended oil (15W-40, mostly at Ford). EGR and oil cooler replaced about 2 years ago, but I am not positive about manufacturers. I think Dorman enhanced EGR and Ford Oil. Replaced a blown ICP Valve in July. New OEM thermostat in about March.

My Deltas have been running between 6-9 during normal operation of 55-75 MPH over local highways. Once I am towing my Jayflight 265 RKS (approx 9k lbs.). I am seeing a 30+ degree spread with poor recovery and the EOT up around 235 to 240. This is at 45 MPH on a 4%+ grade for several miles. Ambient at the time was between 85 and 100*F in the Morning. I am also not hearing the fan's distinctive howl until my ECT is over 220*. This is all with the AC on since I haven't turned that off since mid May due to the triple digit heat here.

My cold soak tempatures are within 1 degree between EOT and ECT.

Thoughts are that I need to do a complete coolant flush and am afraid that either the Fan Clutch wiring and or Water Pump impeller are headed south.

 

I presume you aren't running Ford Gold coolant?? If you are, then a flush and switch to EC-1 rated coolant is important especially in the high heat and towing situations you are driving in.
You will hear from much more expertise on here than from me, but my rig (an RV) is also working all the time like yours, and if I'm towing up those grades in heat, I'll also hit 240 EOT (and my 'normal' delta is less than 10 based on the normal Ford spec test conditions). The only thing that concerns me about your story, is that recovery is poor. My recovery is pretty near normal as far as I can tell, so I know the oil cooler doesn't have serious blockage (but probably has some, as the first owner ran Gold and I had to do a thorough flush with Restore - lots of info on here about doing that).

 

My fan will step up in speed at 207 F water temperature. Sometimes it may not be terribly audible if I'm below 2000 RPM engine speed, so I usually watch FSS on the SGII till I'm satisfied it's working like it should.

Is your 240 EOT at a 220 ECT? You mention a 30-40 F spread and also an ECT of 220+ as the fan threshold. Is the 30-40 a "steady-state" spread while towing, or is that worst case as the fan has cooled the coolant but the oil hasn't caught up? I can get spreads in the upper teens when the fan kicks on, especially if coupled with a load reduction on the motor.

I don't tow on grades like you mention, but 220 F water temp doesn't seem out of reach based on ambient temps you mention. I towed my 8K bumper pull yesterday in 90 F ambient and the fan was running most of the time trying to keep things at 207 F. Highest I saw was 211, maybe 212 up a small grade. But my grades are over in 10-15 seconds, not minutes. I've also noticed that if I tow below 60 F ambient I rarely will see 207 F water temperature.

 

Will, does your Edge read the fan speeds?

Empty, my ECT/EOT run about the same as yours. Mainly around 6* spread.

Climbing those grades in Central Cal this past spring with our 5th wheel, I saw the same spreads as yours. Actually saw my ECT break over 225* and never experienced the de-fuel that I have read will happen at those temps. (I was grossing 22,500)

I was thinking about putting in a fan switch, just didn't get it done. I did have Matt at Gearhead adjust my unlimited tow tune to lower my fan temps, but, I haven't been back in those kind of situations to see if it would help having the fan come on at lower temps through the tune.

 

Sean, I'm pretty sure that 225 defuel temp for ECT is not correct...what you typically see quoted here is a 253 defuel point for oil temp. I haven't come across a defuel point for coolant, but if one does exist its not as low as 225, as I've driven above that many times.

 

Will,

Just based on my feeble memory, a member here we were running down all sorts of rabbit trails with, that had the same symptoms as you, had an extremely simple fix:

He replaced the thermostat. It acted "normal" in all but hard pulling conditions and then would run hot...

Have you replaced the t-stat yet or ever?

Scott

 

Siesta, I'm still running the Ford Gold Coolant. That is one of my thoughts on things to do.

Sean, I don't think that my CTS2 has fan speed as a PID.

Scott, I had the Thermostat replaced back in March-ish because it was not allowing me go get up to tempature (stuck open).

I haaven't hit the de-fueling oil tempature yet, but it has been close at times. I am researching a shop to do the PROPER coolant flush because I HATE doing mechanical work on the street in front of the residence.

I haven't downloaded the last data log that I did, but it seems that the oil temp recovery lags WAY behind the coolant. I.E. ECT 194 EOT 228 on a down grade and it takes several miles (4+) to come back to "normal".

 

Yes, the OP stated that he replaced it last March.

 

Have you tried removing the grill and taking her and 5 dollars worth of quarters to the local car wash and wash out the coolers that are in front of the radiator? Just be careful to not bend the fins on the coolers with the high pressure wand, make sure you go to one that has the bug remover step.

 

when i did my oil cooler, normal running temps were within 1-3* up to 85mph. With a load they never got above a 9* delta. Before i did it mine would operate 8-10* delta, once i put a load on it, it would clumb to 30* delta, eot being hotter. Sounds like your oil cooler is plugged to me.

 

I would suspect the oil cooler also.

 

Moderators...the link in Tech Folder for Coolant Flush procedure (PDF file) doesn't work (at least for me). Can the link be repaired or replaced?

Also, where are y'all recycling/dumping your old coolant? Most places I've checked with won't accept coolant.

Thanks,

 

I would agree with that, but then you can have a discussion about degree (literally/figuratively) -how much plugging is too much. The only 'by the book' guidance for the oil cooler is Fords's spec at 65 mph and having less than a 15 degree spread. But in loaded conditions, driving in heat, a 'partially' plugged cooler will result in some pretty hot oil even though the rig passes the Ford test on the level unloaded. I think what you do with that condition depends on how vigilant you want to be (close monitoring) and what steps you take to minimize heat. For example, the OP still has to run his AC, which makes matters worse, so that is a consideration. In my case, my delta's are similar to his, and I also suspect some degree of plugging based on the silicates I saw in my system at time of purchase. Nevertheless, I can manage the heat. I avoid running AC on grades, and will even turn on the heat....this makes a noticeable improvement in temps. To keep my interior cool for long grades I can run rooftop AC on propane.
One thing I'd bet on in the OP's situation is if he doesn't dump the Gold and do a complete flush with Restore, his cooler will be toast much more quickly.

 

Thanks for the guidance guys. I’m looking at a flush and coolant change in the spring before towing season sets in again and to continue watching my deltas for oil cooler health. Gotta love finance challenges.