So as of recently I have noticed that the temp. sensor on the gauge cluster fluctuates rapidly and randomly from time to time. Usually it stays in the normal range but some times it will shoot straight up to nearly right before the warning line and it never passes it. Usually I will start moving and it will quickly cool down but sometimes it does it when I am moving too. I am running basically a stock 03 setup.

Here are my thoughts on what it cold be, btw it never throws a code, never seen any smoke and it honestly seems to drive 100% fine all the time soo...

could it be?

fried sensor?
needs more coolant?
bleed the system?
an actual overheating issue I havent mentioned, anything would help. Thanks

 

Bad sensor/ gauge. It only polls once every 60 seconds (same for the gas gauge). If it's fluctuating like you describe, it's going bad. But of coarse, you still need to verify that you don't have any mechanical problems too.

 

Is there any way to confirm this? Do you happen to know where the sensor is located so I can take a look. Do you know what it costs to replace it? Thanks!

 

It's located toward the back of the motor on bank1. Not sure what a new sending unit would cost though.

Assuming you don't have any mechanical problems, the best way to diagnose it would be to pull the sending unit and replace with a new one.

 

Interesting, I never knew that. So you're saying the gas gauge only receives a signal from the sender once a minute? That would explain why my gas gauge is so loopy..

 

did you do a coolant change or something?

 

nope no coolant change

 

any more ideas? is this thing hard to replace?

 

???

 

Sensor is easy to replace, its located on the top of the coolant hard pipe that runs to both of the cylinder heads, in the back of the engine. The sensor has a blue connector, its located on the passenger side.

 

Thanks! Now I just need to find the part number and pick one up, is it possible that this issue is related to the thermostat as well?