I thought I'd post this in case anyone is having the same problem.

Tom

TSB
06-21-15 MIL ON - DTC P1285 / P1299 - 5.4L 3V / 6.8L 3V - FALSE OVERHEAT

Publication Date: October 13, 2006

FORD: 2005-2007 F-53 Motorhome Chassis, F-Super Duty



ISSUE:
Some 2005-2007 F-Super Duty and F-53 Motorhome chassis vehicles equipped with a 5.4L or 6.8L 3-valve engine may exhibit an engine temperature gauge indicating an overheating condition with the malfunction indicator lamp (MIL) on with diagnostic trouble codes (DTCs) P1285 and P1299.

ACTION:
Performing normal engine cooling system diagnostics in Workshop Manual, Section 303-03, if it is determined that the engine is not physically overheating (coolant expulsion), install a new thermostat and crossover pipe. They have been revised for improved cooling system flow characteristics.


PART NUMBER PART NAME
7L3Z-8575-A Thermostat - 5.4L
7C3Z-8575-A Thermostat - 6.8L
3L3Z-8C368-A Crossover Pipe - 5.4L
3L3Z-8C368-B Crossover Pipe - 6.8L


WARRANTY STATUS:
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
Note: Normal would be from 190 to about 220. The actual boiling point of the system is about 262. 212 water+5 for coolant +15x3 for cap pressure =262.

This message has been edited. Last edited by: Fakrwee,

Bump....