2004 4.0 vin k motor swap with 2003 vin k 4.0 HELP

[2004exlporer4.0]

coolant temperature gauge is not registering when vehicle is on

Thanks for all of the great advice! The motor is in AND SHE RUNS!!! The 98 4.0 SOHC is purring like a kitten in my 2004. Once i lined up the torque converter studs with the flexplate holes everything just fell into place.

NOW that she is running the dumb temperature gauge is not registering. I had it running for 5 mins and it is probably around 100-120 to the touch. I am going to check for a bad fuse when i am done with lunch.

What sensor should i replace or where should i start? Keep in mind that when i purchased this vehicle i knew that it had overheated and the old owner said that the hose connecting the thermostat to the radiator blew off.

 

[fordbluefamily]

Should be the sensor on the thermostat housing. Check the wires really good and make sure they haven't been pinched. Did you fill the engine with coolant prior to putting the thermostat in and capping it off? It can be next to impossible to get all the air out if you don't prefill the engine and that will cause a low reading as well

 

[2004exlporer4.0]

I did prefill the coolant before i replaced the thermostat.... My concern is that this thing is going to overheat. I have been told to ground the sensor and check to see if the gauge works.

As for the coolant being filled prior to me doing the thermostat, what is your opinion as to relieving air pockets?

As to the low reading the gauge literally does not even budge once the car is turned on, it looks as if their is no power going to the gauges because it hangs well past C.

 

[2004exlporer4.0]

The sensor on the thermostat housing spins freely. I tried to tighten it and the sensor just continues to spin. Is the housing for the sensor my problem or is it the actual sensor?

In addition, after i replaced the thermostat upon start up there is a weird whirring noise coming from the housing.

 

[fordbluefamily]

The sensor is simply clipped in. No threads. It may be dead hence the previous problems. You want to make sure you get a new o-ring if you replace it as they are known to leak. You can wrap it in Teflon tape around the oring in a pinch. Google "Ford gauge test mode" and see what you have there. You should also monitor the temps via obd2 for the first warm up or two to ensure the tstat is functioning. The dash gauge is nothing more than a warning light. It's fake

 

[2004exlporer4.0]

The sensor is simply clipped in. No threads. It may be dead hence the previous problems. You want to make sure you get a new o-ring if you replace it as they are known to leak. You can wrap it in Teflon tape around the oring in a pinch. Google "Ford gauge test mode" and see what you have there. You should also monitor the temps via obd2 for the first warm up or two to ensure the tstat is functioning. The dash gauge is nothing more than a warning light. It's fake

So i cleaned off the sensor and let it run for another couple of minutes and the gauge actually began to move. I was comfortable with letting it run because i had my OBD2 plugged in and could see the engine coolant temperature like you said (i had no idea).

The temperature of the coolant at a fraction above the C was 120. What is the normal operating temperature of this motor? I would imagine somewhere between 160-180?

 

[2000StreetRod]

190 degrees F

The standard thermostat is 190 degrees F. The sensors on the 1998 screw into a brass fitting that easily separates from the plastic housing. Once that happens it will usually leak. There are numerous threads about upgrading to the clip in type sensors used on your 2004. If you still have the 2004 housing and sensors I advise that you swap housings and sensors.

 

[fordbluefamily]

I see between 187 and 197 on mine with normal driving. When towing in summer might see 200. Keep squeezing that upper hose and adding coolant. The third gens with the coolant tank take forever to bleed. Mine took days of driving/checking to level out. They added a pressure cap style radiator to the 4th Gens and they bleed way faster.

 

[2004exlporer4.0]

Thanks streetrod, i am hoping that i dont have to upgrade it since i just want to sell it now that it is running good. Thanks for the help through out this build it was some good stuff!

When i plugged in my obd2 i let the truck run for about 5 mins or so revving it to help it get hot. When it was finally nice and warm i noticed that the about a fraction under the half way mark it hit 205. I continued to rev it and noticed that it was starting to increase to 215... then to 220 and i told myself if it hit 230 i would shut it off, well it did. Now i have yet to get the coolant level to where it needs to be. i believe that i am about half a gallon short of anitfreeze. The weird thing is that when i let of the gas instead of getting hotter it cooled back down to 215 turned it off and it got to 200 fired it back up and it was solid around 210 then i revved it and up it goes, again.

I used 2 gallons of 50/50 so should i maybe add the last half gallon in 100% antifreeze?

Is this just an air bubble?

What is the actual capacity of antifreeze? (i removed literally 95-100% of it)


Could the sensor be shot and it would be wise for me to replace?

I am going to drive it around today after i return the old motor to pick n pull and i will leave the OBD2 plugged in and make sure that it doesnt go past 225. A number that would be better than 225??? Haynes says 220 is normal from what i have read....

Thanks again gas monkeys!

 

[fordbluefamily]

Fwiw, I have never seen numbers that high on mine. I believe you still have an issue. Is your fan clutch working? New water pump? Flushed out the radiator?