Hey everyone. I'd like to start off by thanking everyone for all the help I've gotten over the past week with my new to me f-250. I replaced the heater core today and now I need to replace the thermostat. I've never done one of these and need all the advice I can get. Is there anything I should know before starting? About how long will it take?

 

Shouldn't be hard to do-easier than the heater core. What engine is in your F250?? What year??

 

1996 351w...I've got to put this in my sig

 

I have a 302. I believe that a 351 has the same procedure to remove and install a thermostat.

Drain the coolant and I remove the top radiator hose from the radiator and themostat housing to be able to get to the thermostat housing easier. Or just bend the engine side of the top radiator hose out of the way.

Remove the thermostat housing bolts and the bypass hose and remove the housing and the thermostat-after giving it a quarter turn counterclockwise. What is neat about these Motorcraft thermostats is that they screw into the intake manifold and remain in place when reinstalling the housing and bolts. This helps because the thermostat is vertical-not horizonal like other vehicles.

Be sure to use a new gasket with sealant. And be sure to install the gasket before installing the thermostat.Make sure that the thermostat is facing the same direction as the original.The spring side should be towards the intake manifold. Turn the thermostat one quarter turn clockwise to lock it into the intake manifold. The correct sequence of intake manifold,gasket,thermostat,housing is important to make sure that there isnt leaks. Reinstall the bypass hose and upper radiator hose to the themostat housing.

The lower bolt on the themostat housing is a bitch to get to.(Take your time and cussing doesnt hurt neither. Just keep small animals and children away.Good anyhow-to make sure that the old coolant doesnt hurt anyone/anything.)

Be sure to use a Motorcraft thermostat with the correct factory opening temperature.

After installing the new coolant-let the engine warm up and check the temperature guage and make sure that it is normal and that the upper radiator hose is warm after the engine guage shows normal temperature.

 

Drain the coolant below the level of the T-stat

Disconnect the bypass hoses at the water pump & intake manifold

Remove the bypass tube, then remove the water outlet housing attaching bolts.

Bend the radiator upper hose upward and remove the thermostat & gasket. Make sure you pay attention to which way it goes it.

To put back in:
Clean the water outlet gasket surfaces & coat new gasket with water resistant sealer.

Position the gasket on the intake manifold opening

Install the thermostat in the intake manifold with the copper element toward the engine and the thermostat flange positioned in the recess

Position the water outlet housing against the intake manifold and install & tighter the attaching bolts to 12-18 ft lbs.

Install the water bypass line and tighten the hose connections

Replace lost coolant.

Enjoy!

 

192-195 degree therm. is what you need, do not go to a lower temp therm. It will cause problems with the EEC computer and give you bad mpg.

 

X2. The PO of my truck did that, and it's bad news. Plus I have heard that a 160° T-stat will double the engine wear rate over a 180° T-stat. I'm getting a 195° one as soon as it's truck driving season for me.

 

Thanks a lot guys. Anyone know about how long it takes?

 

Shouldnt take more than one hour of constant work. It seems that almost half of the time will be spent removing and installing the bottom water pipe/thermostat housing bolt!!!!

Be sure to make sure that the thermostat is locked into the intake manifold BEFORE placing the water pipe housing back into the intake manifold. If the thermostat is a locking one-and it isnt given a quarter turn to lock it into the intake manifold-there will be leaks-believe me.

 

Thanks a lot, guys. Got it replaced this morning and everything went pretty smooth.

 

How long did the job take??

 

You were right. The heater core was much more of a pain to replace. I think it only took me something like 30 minutes.