Hi, new today to this forum, did a search on my problem but could not find similiar issue.

Changed the Fan/clutch with OEM from TeamFord-LV last fall, on trip south in November and return in January the High Fan Roar did not come on when temperature needle went into red, and my Scan Guage indicated up near 239 degrees. Do not boil over, no coolant loss, turn on heater, open windows, slow down on hill climb to keep temp down.
Understand that the center of the radiator clogs first, which negates how the Fan/clutch receives its heat sensing to kick into higher fan speed.

Did a Prestone Super Radiator Flush with 2 bottles last week, and today a Prestone Super Radiator Cleaner with 3 bottles, as both indicate if over 12 quart capacity, add 2nd bottle. Because capacity is 30.6 qts, I added 2 bottles, ie: 3 today, following instructions with filling with water both times, and running engine for 10-15 minutes once reaching normal temperature (190-degrees) with heater & heater fan on high.

Someone suggested on another forum that I warm up engine and then cover grill with a blanket or something to cause the temperature to rise 15-20 degrees about the thermostat openning, but I am not able to find the spec's for my thermostat.

Sorry for the long tread, but any input on resolving my issue would be greatly appreciated. Eugene.

 

Thread closed, there's a duplicate in the V10 forum.

https://www.ford-trucks.com/forums/7...lfunction.html