Help Code P0117 after replacing parts

[Rubixcuve]

Hello I Have a 98 Mercury mountaineer v8. And recently I replaced both the engine coolant temp sensor and the engine coolant sender sensor along with the thermostat. The reason why replaced them is a few months ago here in Arizona we got hit with a few heavy sand storms that brought down heavy rain and weather outside dropped dramatically. During one of this storms my engine light came on and noticed my temp gauge was at standing still at the letter C. So I hooked it up to a obcd code reader and it came back with a code P0125. So once I found out that it was the engine coolant sensor thats when I decided I would change all of these parts out. But now I have rough start, temperature gauge stays at the very bottom won’t even budge to move and now i have a code P0117 That Is in relation still with the the coolant temp sensor. Am i missing something here? And I did ground the temp gauge so that is working in case you wondering.

 

[Turdle]

Low coolant level will cause both the original, and new codes.
you are loosing coolant, possible you did not purge the air out of the system when you refilled coolant. parking the vehicle on an uphill incline or raising the front of the truck with a jack helps get the radiator cap higher than the heater core. This helps the air escape quickly.

Check the reservoir is not clogged at the bottom outlet nipple. if it is , the clog will act as a one way valve and not allow coolant flow back to the radiator. Pressure from the radiator will overcome the clog and pass coolant to the reservoir though.

 

[Rubixcuve]

Low coolant level will cause both the original, and new codes.
you are loosing coolant, possible you did not purge the air out of the system when you refilled coolant. parking the vehicle on an uphill incline or raising the front of the truck with a jack helps get the radiator cap higher than the heater core. This helps the air escape quickly.

Check the reservoir is not clogged at the bottom outlet nipple. if it is , the clog will act as a one way valve and not allow coolant flow back to the radiator. Pressure from the radiator will overcome the clog and pass coolant to the reservoir though.

Low coolant level will cause both the original, and new codes.
you are loosing coolant, possible you did not purge the air out of the system when you refilled coolant. parking the vehicle on an uphill incline or raising the front of the truck with a jack helps get the radiator cap higher than the heater core. This helps the air escape quickly.

Check the reservoir is not clogged at the bottom outlet nipple. if it is , the clog will act as a one way valve and not allow coolant flow back to the radiator. Pressure from the radiator will overcome the clog and pass coolant to the reservoir though.

no i did not purge it and the reservoir it still pretty full. I’m gonna purge as we speak hope that works. And the car has been leaking a little bit from the water pump which I’m replacing this weekend as well.i will keep you posted if the purge helped.

 

[Rubixcuve]

Low coolant level will cause both the original, and new codes.
you are loosing coolant, possible you did not purge the air out of the system when you refilled coolant. parking the vehicle on an uphill incline or raising the front of the truck with a jack helps get the radiator cap higher than the heater core. This helps the air escape quickly.

Check the reservoir is not clogged at the bottom outlet nipple. if it is , the clog will act as a one way valve and not allow coolant flow back to the radiator. Pressure from the radiator will overcome the clog and pass coolant to the reservoir though.

I went ahead and purge the car and that didn’t help. But i did noticed that the coolant was just warm and not hot. Do you think the thermostat is not reaching its point to open up properly or could be that is not the right spec? My only hope now is when i replace the water pump. It will get rid of the code now and get the temperature gauge back to working properly.

 

[Turdle]

Do you get hot air from the heater when selecting floor function and hot temperature?

If it is less than desirable, does it get warmer if you hold the engine revs over 2500 RPM's?

 

[koda2000]

Your original code (P0125) could have been related to you thermostat being stuck open and not the PCM's coolant temp sensor. It means your coolant is not getting hot enough to enter closed loop mode. Did you verify that the coolant sensor was your problem before replacing it?

If/when you replace the t-stat, make sure the "rattler" is at the top. I've never had to purge air from a 5.0L. If your new t-stat doesn't have a rattler valve, it should. If not you can drill a small hole in the t-stat's base an install the hole at the 12:00 'ish position. My t-stat housing a a small bump near near the top, that's where I put my rattler.

Tip: Install the t-stat in the housing and install the t-stat housing gasket with some Hi-Tac or a smear of silicon to glue it to the housing. Let that dry before attempting to reinstall the housing on the engine. This will hold the t-stat in place and prevent you from cracking the housing when the bolts at tightened.

 

[Rubixcuve]

Do you get hot air from the heater when selecting floor function and hot temperature?

If it is less than desirable, does it get warmer if you hold the engine revs over 2500 RPM's?

No just warm but once It does reach its higher rpms It gets warmer but not hot.

 

[Rubixcuve]

Your original code (P0125) could have been related to you thermostat being stuck open and not the PCM's coolant temp sensor. It means your coolant is not getting hot enough to enter closed loop mode. Did you verify that the coolant sensor was your problem before replacing it?

If/when you replace the t-stat, make sure the "rattler" is at the top. I've never had to purge air from a 5.0L. If your new t-stat doesn't have a rattler valve, it should. If not you can drill a small hole in the t-stat's base an install the hole at the 12:00 'ish position. My t-stat housing a a small bump near near the top, that's where I put my rattler.

Tip: Install the t-stat in the housing and install the t-stat housing gasket with some Hi-Tac or a smear of silicon to glue it to the housing. Let that dry before attempting to reinstall the housing on the engine. This will hold the t-stat in place and prevent you from cracking the housing when the bolts at tightened.

Yes i did once i put on the code went away but came back with the most current one. And rattler? Not quite sure what you mean by that.

 

[koda2000]

Yes i did once i put on the code went away but came back with the most current one. And rattler? Not quite sure what you mean by that.

It's a little brass valve on the rim of the t-stat base. It lets air escape from the engine before the t-stat opens. If you shake the t-stat it rattles.

If you engine's not getting hot (around 190-195F) your t-stat not working correctly (stuck open).

 

[Rubixcuve]

It's a little brass valve on the rim of the t-stat base. It lets air escape from the engine before the t-stat opens. If you shake the t-stat it rattles.

If you engine's not getting hot (around 190-195F) your t-stat not working correctly (stuck open).

Oh I will have to look at it to see if it dose have that brass valves. And I was wondering the whole time because I hooked it up to the computer and it’s only ready at 170 coolant temp the highest. Mades me wonder if that thermostat that I bought is not meeting the OEM requirements. I might have call autozone too see which model part they sold me and see it it meets those oem specs.