2004 Ford F-150 4.6L Thermostat Replacement | Trouble Code P0128

I needed to replace the thermostat on my 2004 F-150 (4.6L V8) due to the thermostat being stuck open. My check engine light came on and using my Gryphon programmer I was able to read the trouble code P0128 and verify that the coolant temperature was much lower than normal.

After draining the coolant from the radiator I disconnected the air intake and moved a bracket holding the power steering fluid reservoir as they both sit right above the thermostat. Once those are out of the way the bolts holding the thermostat housing to the engine block can be removed.

At this point the thermostat and the gasket can be taken out of the engine. Always compare the existing parts to the new ones to make sure the fit and function will be the same. Put everything back in reverse order, snug the radiator drain plug back up (DO NOT OVERTIGHTEN) and refill your system with 50/50 coolant.

★ 195°F Thermostat – Stant 13779: https://amzn.to/3vxeaiF
★ Thermostat O-ring – Motorcraft RG571: https://amzn.to/3vvqjEK
★ Spill-proof Funnel: https://amzn.to/3tutIRq
Links are affiliate links. It doesn’t cost you any extra and we get a few cents back when you use our link. Thank you for your support!

I invested in a spill-proof coolant funnel to help prevent air bubbles from getting in my coolant system. It worked great and I can say my truck reaches operating temp quickly, does not overheat, and the heat works better than it ever has.

I rolled over 200,000 miles in this truck this past week and like a badge of honor she developed a new clunk coming from somewhere in the rear end. Subscribe to our channel so you’ll see when I get around to addressing that. Thanks for watching, everyone!

★ Follow us on Instagram: https://www.instagram.com/gwphomestead/
★ Thermostat housing to engine block torque spec: 19 ft-lbs (http://www.torkspec.com/torkspecme.aspx?KI=11-4.6L-281ci-V8)
★ Video that helped me: https://youtu.be/luR1gnsxeHo
-
OBD-II Trouble Code P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
195°F Thermostat: Stant 13779
Thermostat O-ring: Motorcraft RG571
-
#Ford #F150