Hello All,
My problem is my temperature differential between water and oil is way greater than the 15° allowed and it appears to be growing. First I’ll give you a history of what I know and what I’ve done. Please excuse me if I get a little long winded as that I’m sure someone will ask. Please read all before jumping to the obvious conclusions
The truck is a 2004 (build date 01/04) F250, SD, 6.0L PSD, CC, 4x4 with 247,000 miles. As far as I know, there are no tunes, all stock. Its primary duty is to pull my 8,000lb 5ver. I bought it late last fall from the local Ford dealer, for a good price, as is. I had them do a complete service & dianostic check and they gave the engine a clean bill of health. Since camping season was over, I had all winter to work on it. That also meant that I didn’t have a chance to drive it under load until this past spring. When I bought it, it had 242,000 miles on it.
Over winter and this spring I was running a temperature difference of about 15° with no load. In early spring I took my 5ver to the dealer for some work and noticed about a 20° difference while under load. In early August, I took a 2,800 mile round trip with the 5ver, going out the difference was in the low 20’s, and coming back it was in the upper 20’s. I just got back from a camping trip and am now running in the mid 30’s. These are after a period of flat driving for everything to level off.
I’ve also had the oil tested and it came back with high traces of coolant. Sodium and potassium were high prior to the 2,800 mile trip, changed oil, rechecked after I got back and they were at about half the previous values, not sure if this is relevant or not. Since the above work has been done, I’ve had to add about 1 gallon of coolant but this also includes 2 coolant filter changes plus any possible air pockets in the system from doing the work.
Now that camping season is done again for the year, I got all winter to work on it, or have someone else work on it.
Coming back from the recent camping trip, Water was running between 210° & 225°. Oil was between 235° & 250°, seeing a high of 257° up a long uphill pull. All temperatures are from a SGII. Temperature difference after cold soak is less than 1°. SGII reports no codes found, FICM voltage at 47+
I have the gut feeling that something is wrong with this engine. Runs like crap until it warms up, occasionally will miss, coolant seems to be slowly getting away, at times it seems to be struggling more than it should to pull the camper, etc. Nothing major on its own but it all adds up to that gut feeling that something is wrong.

What I’ve done:
After the spring trip to the dealer, I did an EGR delete (Sinister Diesel), new oil cooler (Ford), coolant flush (before starting oil cooler replacement with distilled water and VC9), coolant filter (Dieselsite), turbo rebuilt, CCV reroute, belts, hoses, etc. Previously I had done the blue spring upgrade. Recently I replaced the EOT temperature sensor.
After replacing the oil cooler, I cut the old one open, it looked new inside. No traces of clogging. Obviously this wasn’t the cause and didn’t solve anything.

My questions:
1) What else could be causing such a high temperature differential?
2) What could be causing it to grow?
3) Could my oil temperature really be that high?
4) Could my SGII be reading incorrectly (I’ve rechecked the code values, they’re OK)
5) How would I go about verifying the temperatures independently? Where & how could I attach a second temperature gage?
6 )With an engine that has this high mileage, is it cost effective to spend big $$$ to repair if it’s a major problem such as head gaskets? Or would engine replacement be better for the money spent?
7) Where do I go from here?
Again, sorry for being so long winded. I am just trying to provide all relevant information. I'll try to reply to all questions but I'm
working 12hrs a day and that doesn't leave much time to monitor a web site, so if I'm slow to respond, please be understanding.
Thanks in advance to all who reply.
knuss3807

 

That oil temp is way too high. No more towing until that problem is identified and fixed your gonna melt something down if it keeps going like that!

Eric

 

Also, is your Fan Clutch kicking in? It should kick up at about 210f ECT and step back down at 195f ECT. Have you checked your Thermostat?

Traces of coolant in your oil? Hmmmm.

Eric

 

Oil/coolant deltas are checked UNLOADED and after a 20 mile drive @ a set speed of 60-65......not loaded and under sever service or climbing hllls.....just fyi. Do this first before you think you.have a problem.

 

Incorrect.

Per TSB 09-8-3:

 

did you notice the power go down with an ect above 223 ?

 

Whoa......that is news to me and possibly bad info passed onto me on this site by reputable guys.

 

I don' t understand what you're saying is incorrect. Tbe dealership does not hitch up a trailer or fifth wheel (loaded) to perform tbe TSB.

 

After you change the oil cooler in spring of this year, what was the temperature difference between water and oil?
When did the temperature started to creeped up, how many mile after the oil cooler change?

Don't understand about temperature difference were so high and the oil cooler wasn't clogg up.

 

It doesn't say to hook up a trailer. It also doesn't say to loaf the truck along at 60-65mph for 20 miles before checking the deltas.

 

Nor does its say to hold WOT Max Boost for 20 miles. The fact is its hard to "loaf" in one of these trucks, unless you try. The suggestion made by Joe Blow is not incorrect rather part of a number of things that can narrow the problem down through systematic trouble shooting.

If he'd like the dealer to perform the TSB, It certainly is not a bad idea. I had it done to confirm my diagnosis of compromised headgasket(s)

Considering the temps the OP has been experiencing the last thing I would suggest is a Wide Open Throttle run after achieving NOT. Running the engine at 60-65 for 20 minutes is sufficient to have accurate numbers to work with for what Joe was suggesting.

Eric

 

Did you even read the TSB?

 

It reads more to me that the vehicle is brought to operating temperature, ran at WOT and then at speed limit start taking readings.

I cannot find the TSB that mentions running at a constant 60-65mph for 6 miles and having to maintain a differential of 25 degrees between ECT and EOT.

8-3-7, 8-11-3 and then 9-8-3 were the follow ups.

Josh

 

you said you recently replaced the oil temp sensor? why? did it fail or give false readings before or just stop working also do as egregg57 says and replace your t-stat. your coolant is what cools your oil thru heat exchange

 

Yes, I have the TSB, read it and performed the portions I was able to and gave the truck to ford to perform it in its entirety. I mean no offense. The OP has unusual deltas for his configuration. Could be as simple as a T-stat, or a sheared water pump impellor, erratic fan clutch, restricted flow in or around the radiator, restricted oil cooler too.

But hopefully not the oil cooler again.

Is there any signs of venting from the degass bottle?
What are you using for coolant?