[Joe DePasquale]

Hey everyone i need some help... 2 weeks ago my check engine light came on so i brought my 2013 challenger sxt to autozone for a test and they said my thermostat was probably going bad and that i should replace it. So i did had my friend clear the light and within 50 mi it came back on, brought it back to autozone and they now said the sensor must be bad. Changed it last night, cleared the code again and this afternoon it came back on again with in 50 miles of resetting the code. I am out of ideas. Has anyone else had this issue? The car isnt overheating, temp gauge doesnt go past 1/2, ac blows ice cold and heat works perfectly. Its only got 64,500 mi on it. Any help would be appreciated.

 

[Rockster]

Hey everyone i need some help... 2 weeks ago my check engine light came on so i brought my 2013 challenger sxt to autozone for a test and they said my thermostat was probably going bad and that i should replace it. So i did had my friend clear the light and within 50 mi it came back on, brought it back to autozone and they now said the sensor must be bad. Changed it last night, cleared the code again and this afternoon it came back on again with in 50 miles of resetting the code. I am out of ideas. Has anyone else had this issue? The car isnt overheating, temp gauge doesnt go past 1/2, ac blows ice cold and heat works perfectly. Its only got 64,500 mi on it. Any help would be appreciated.

Check the T-stat is opening properly. Start the cold engine and let it idle. Check the hose to the radiator. It should remain cold/cool -- there might be a bit of coolant flowing past/through the "closed" T-stat which would have the hose warm up some but it shouldn't warm up much -- until the T-stat opens then the hose should get warm. I don't think it will get warm/hot enough to burn but it will get warm and then hot as the coolant flows through the now open T-stat to the radiator.


You also need to check the coolant temperature. You can do this with an OBD2 code reader/data viewer that allows you to view engine telemetry in real time, and this includes the coolant temperature. If you watch this reading closely you'll see the temperature go up and up and up then (maybe) drop a bit as the T-stat opens and a cold slug of coolant flows from the cold portion of the cooling system into the engine and eventually past the coolant temperature sensor. The drop may not be that dramatic but I think you should see it.


You also should try to confirm the coolant temperature by using something -- an infrared thermometer -- that lets you read the temperature of say the water pump housing or where the coolant sensor attaches. The coolant temperature displayed by the OBD2 code reader is based on what the coolant temperature sensor provides (a voltage level) which is converted into a digital number by the engine controller.


The results of the above will help you know what to do next.

 

[Joe DePasquale]

Thanks Rockster I will give that a try

 

[jcruikshank]

Are you still running a factory thermostat, or have you dropped down to a 180F? The P0128 is a common code for many owners using a lower temperature thermostat, but usually only during the winter or cold mornings.

 

[F8Dragon]

One of my nephews has an 06 Charger that kept getting the same code, replaced the sensor and it still came back, got a sensor from the dealer and the code went away. I can't say that your issue is the same but Dodge seems really picky about anything electronic.