I have noticed that my thermostat appears to be "sticking" every now and then. hasnt been changed in quite some time, what would be the correct thermostat temp? its a 1994 F150 4x4 XLT, 302 engine, Manual transmission, I think 190 is stock? What would be the advantage of going to a higher or lower temperature setting. Dont really see any reason to not go to a lower temp on the thermostat. Thoughts?

 

195 is factory....I would just go back in with that. The ECM needs to see 185 to switch into open loop. There's a few guys that run 180s an 160s they'll have to chime in to let ya know how they work.

 

Lower temp thermostats richens the motor for a little more power but they waste gas, stay with a stock 195, there are no thermostats that I know of that is over 195. The ecu is programmed for 195 for the proper fuel curve.

 

I'll take power over fuel economy, buy can't think it would make a noticeable difference.

 

While I would also recommend the 195 stock thermostat, the ECU does switch into closed loop long before that temperature.

 

if you have the California Emissions ECU (california calibrated) you'll be better off staying with the 195 degree stat... if its sticking just flush the system... you're supposed to flush it once a year but everyone knows we dont... I did mine 4 years ago and and if I drive it cold it will stick and wont open until it hits 185 or so...

a good flush will usually fix the issue...

if you have a mid/eastern calibrated ECU you can safely drop the stat to 180 or 160... the lower temp cause the fix mixture to appear more rich from the cooler running temps... engine needs more fuel to make the same power the hotter it runs...

in essence the mixture will be richer and the O2 will pull it back to normal and you'll make the same power and use less gas...that and a good tuned ignition system with a High Output coil will make a world of difference...