Update: It ended up being an air pocket! Bled the system few times, and everything now is in working order. Thanks!

Hello,
Background: I was running a Mishimoto thermostat, it went bad, and overheated the engine (reached 295F). Luckily only the water pump went bad, and after replacing it along side with a new mishimoto thermostat, everything is running fine now (coolant temp via evoscan is ~165F)….however, my cluster gauge is still reading at max whether the engine is cold or warm, even when the key is in the ON position and engine is off.

So far I have done the following to remedy the issue:
1) Used a funnel and bled the coolant system
2) Replaced the front coolant temp sensor with a new one (Duralast from Autozone).
3) Checked all the fuses
4) Added an extra ground directly from the negative terminal to the thermostat housing.

Has anyone run into this in the past or may have an idea on what I should look for next?
Thanks

 

there are two coolant temp sensors. one that reads to the ecu, which is the one you are looking at on evoscan, and the other that goes to the gauge. The one to the gauge is the one that is in front, iirc. Check the wiring to it. Also I have seen air pockets in the coolant system causing the needle to not respond as quickly as it should.

 

I am on the same page, which is why now days I am driving the car with the laptop on the passenger seat just to be safe
I checked the single wire to the temp sensor connector and it seems ok. Not sure what else to look for
Thanks for your feedback

 

replace the temp sensor. they're cheap sensors, about $20

 

It ended up being an air pocket! Bled the system few times, and everything now is in working order. I also did replace the tc as suggested. So it could be a combination of both.
Thanks for the help