Is there a How to about changing the thermostat? [Archive] - Forum


View Full Version : Is there a How to about changing the thermostat?

12-21-2006, 09:30 PM
I tried searching, but didn't find anything in the How to section.

My temp. gauge decided to not move anymore, so I suspect the sensor is bad.
Is there a way to test the gauge, or should I just change the thermostat sensor and be done with it? Let me know what you think, I know a lot of people have done this before. just need a little help.


12-21-2006, 09:36 PM
yah the gauge can be tested with a scan tool that has bidirectional controls, maybe a snap on or tech 2 or genisys, but you can also put a resistor in between the terms on the temp sensor harness and change the temp.. it should run a self check anytime you turn the vehicle on anyway.

but all the sensor does is change resistance in reference to gets voltage from the pcm, and pending on the temp of the coolant, returns back a resisted voltage that is less than it recieves, and the amount it is less than source voltage tells the gauge how much to move

but like i said when u turn the car on, it should self test and sweep itself

also changing the tstat isnt too hard, removing the throttle body helps, but i never do.

12-21-2006, 10:21 PM
yah...well check this one ( also

12-21-2006, 10:25 PM
So if the needle on the temp gauge doen't budge at all... even when you start the car... then what? wiring issue?

12-21-2006, 10:32 PM
well usually not wiring, usually the sensor will go check the wiring, replace sensor with a resistor and see if the gauge moves, or replace with NGP(known good part)

or you can get very technical and get a variable resist from radio shack(like .20 or so) and plug it in...should be one side post and middle "wiper" on resistor to the harness and have someone turn the dial while u watch the gauge

if gauge moves, then its ur sensor.

12-22-2006, 09:32 PM
Personally, when my thermostat went bad, I just had the shop replace it. You have to take off a bunch of stuff to get to it.

12-22-2006, 11:45 PM
it normally takes me 15 to 20 mins to do mine...and there isnt that much to remove just my $.02

12-22-2006, 11:58 PM
Its not that hard a job (thermostat) but it is a pita if you're never done it before. I didn't take off the throttle body but I suspect it will be much easier that way.

12-23-2006, 09:59 AM
alot easier, but i dont like possibly replacing the tb gasket just cuz i have to switch the tstat...

also on that note, does anyone else with the ss headers notice that the crossover pipe is way too close to the waterneck on the tstat, i think mine is acutally touching a little bit