The original TSB was 65 mph for 20 minutes under 25 degree spread was good
Then WOT, max boost (which is only to about 49 mph) under 15 spread
The tech manual is now cold start and drive 15 minutes @ 1800 rpm - under 10 degrees spread = ok

Josh

 

Good to know, thanks for the update.

We can sit in this thread and debate which test is best until our tongues fall out, but there comes a point where even if you netted a 5-10* decrease in the split based on specific test criteria you're still past the point where replacement is needed. Hitting a 25* split consistently in difference circumstances, that's past where I'd draw a line regardless of what test criteria you're looking at.

 

Without a doubt the guy needs an oil cooler. Just dump the coolant, chem flush, replace the cooler and top off with ELC.

Josh

 

Just a little tidbit for some of the new guys. Some of the info on this site may not fully agree with some of Fords TSB's or recommendations but has been learned thru the school of hard knocks. Unfortunately when the 6.0 was first released that's how many of the techs learned what made the 6.0 tick and become reliable. The 6.0 could have possibly been a money maker for Ford if a little more fore thought and research had been applied. JMHO.

 

Not looking like good news from most of you....just got back from getting a buzz cut and errands.....roughly 20 -30 mins both ways, and I was between 13 -17 delta.....
FICM voltage is at 49, battery voltage at 13+, trans temp no higher than 165.....so at least that's good!

 

You are just barely hitting heat saturation in that time and it would all have to be at highway speeds. On another note some here have been at the 13 to 15 thresh hold for a year or more without it getting worse. Don't be a chicken little.

 

so an update...I went with a restore plus chem flush, and installed fleetrite ELC coolant. Installed XDP coolant filter, blue spring kit, tires rotated, fuel filters changed out, tranny fluid and filter changed out. I'll run it a bit and get her out on the open road and see if my deltas have come down at all, fingers crossed.
Here's a puzzle for you all.....my mechanic said while dropping the pan to do the tranny, he hears this clang, clang, clang....WTF.....He found that three (3) bolts from the valve body were laying in the pan??? What would have caused those bolts to back out like that???

 

You went with just a restore plus? If so, I expect you to have to replace the oil cooler soon. I base it on theory alone, so take it with a grain of salt. Below is from Cummins Filtration site. My theory is that if you use Restore Plus and don't use Restore first, then you are breaking rust, corrosion etc loose from your cooling system and it will be stopped by the gel.

Restore

• Alkaline-Based Cleaner
• Most Effective Cooling System Oil/Fuel Contamination-Cleaning Agent on Market
• Removes Silicate Gel
• 10 Times More Effective than Automotive Distributor Detergent Powders
• Safe for Use in Aluminum Radiators and Heaters

Restore Plus

• Mild Acid-Based Chelating Cleaner
• Safely Removes Rust, Corrosion, Scale, and Solder Bloom - Without Disassembling your Cooling System

(I have a very lengthy detailed writeup of my full steps on my PC. A portion of it is in another topic here) . I started with a water only flush so far, with the thermostat removed. The next steps I am taking is Restore for 2 hours at high idle (1200rpm), then Flush completely after opening block valves and with water hose until ph strip reads less than 7.0. Then Restore plus for 2 hours at high idle (1200rpm), and flush again until ph is less than 7.0 before doing 4 final flushes with distilled water. Flushes consist of tapping into system with a water hose under the degas bottle after removing the heater return hose from the system so that anything that is knocked loose will drain without re-entering the system. Top off with CAT EC-1 rated ELC Coolant and a Sinister Coolant Filtration System.