SO i just went and bought a haynes manual and think i located the sensor. Unfortunately it's at a point lower then i can reach, so i'm just going to chalk it up and take it to a mechanic and have them work on it tomorrow before work. Looks like it's lower middle of the engine in the back. I don't want to start yanking things out either, it probably is a real easy fix, but i'll just bend over and take it

 

-UPDATE-

Went to the mechanic yesterday, he swapped out my sensor, and reset my light and all was good. I drove to work and back home and the light did not come on.

Driving to work this morning and around the same spot that the light came on yesterday, it came on again. Now what puzzles me is that all this happened when the weather got really cold this week. When i got to work, i checked to see if my fans were running and they weren't so i'm not sure if it's the thermostat. I watched the temp gauge all the way to work and not once did it move. I also drove with the heat off to see if that was impacting it and it still didn't budge. My commute is about 45min to an hour long, i figured at some point it would've began overheating if it was the thermostat. At this point i'm wondering if anything is even wrong with the car and it's just the cold weather. I'm going to take the car back to autozone to have them read the code. If it's the same code, then i'm just going to let it ride, but i'm still wondering if it's my thermostat.

 

-Update x2-

So i was looking online for ways to find out if your thermostat is bad. One place mentioned feeling the top black tube leading to the engine from the radiator and see how it feels. So i did that and it felt hot but not extremely hot (Car had been sitting for about a half hour). It then mentioned feeling the bottom tube and see if that's hot. I did that and that was MUCH cooler then top tube. Which means that the thermostat is stuck closed. So i'll probably take it back to the mechanic tomorrow and see how much this will cost me

 

DIY. It's an easy job and you already have the haynes manual. Seriously, it takes like 15 minutes, 30 tops.

 

I would just need somewhere to put my antifreeze that's going to come out right?

 

its really not difficult just somewhat dirty and awkward to reach. most of the trouble is from removing and reinstalling the hoses.

 

a piece of cardboard under the car, and just throw it away when you're done :shhh: Or just a $10 oil pan thingy... I never lost much coolant doing this job. The T-stat housing is near the top of the system (where the upper radiator hose meets the head), so you'll lose some, but it's not like you'll be dumping out all your coolant.

 

how do you get air out of the system? there is a bleed cap right?

 

Jae,

The reason the lower rad hose is cooler is because it's carrying cooler coolant back to the block.

The coolant is pumped through the block and carries away heat from the head and from the sleeves. It travels from the engine to the upper radiator hose to the radiator where it is rounted through the radiator core. The fins on the core dissipate the heat in the coolant and returns the non-heated coolant back to the block via the lower rad hose to redo the cycle. The thermostat is the valve (wax valve as Rick mentioned) the stays shut until the car reaches operating temp. The thermo will open at the correct temp allowing the coolant to flow. additionally, the coolant temp sensor is installed somewhere in the cooling system (in your case, on the back of the block) and reports the operating temp to your gauge and or the ecu. The ecu will make adjustments to air, fuel and timing to compensate for the temperature conditions (the car needs to be at proper operating temp for the catalysts to function). Lastly, because you have a fwd vehicle, you have electric fans. The fans are controlled via a fan switch which is also a temperature sensor. This is in all likeliness installed on your radiator (either a clip on the fins (aftermarket) or a screw in sensor into an end tank (oem).

At a specified temp, the switch completes the fan circuit and the fans will turn on. If the temp doesn't get high enough, the fans wont turn on (extreme winter or even freeway driving).

Here's my question. When driving, does your temp gauge go to the proper operating interval (maybe midpoint or just below mid)? Does the temp sensor not move at all? (stay cold?)

Changing the thermostat is a simple enough proceedure.

1. Drain the coolant into a catch pan using the drain screw at the bottom of the radiator (You can also just pull the lower radiator hose)

(optional: look for the drain plug for the block and unscrew to drain the coolant in the block)

2. Unbolt the thermostat housing.

3. Replace thermostat and gasket. (use a little RTV on the gasket to prevent leaks)

4. Refill the system with 50/50 antifreeze and water.

To bleed:

1. Fill system till you can't put anymore in.
2. Start car with radiator cap off
3. Bring car to proper operating temp.(coolant may bubble out of the system, but make sure to just keep topping it off.
4. Turn off car and top off

I usually repeat steps 2-4 at least 3 times to ensure a full bleed (i usually rev the engine to speed up the heating process. (You need to get the car up to operating temp so that the thermostat will open and allow all the fluid to cycle through the system and carry any air pockets out. FYI, the radiator cap should be the highest point in the cooling system therefore all the air should end up here.

PS:

It's always good policy to change both upper and lower radiator hoses and replace oem hose clamps with newer screwdrive clamps. It's just good measure and cheap and convenient to change it all now. Another shadetree mechanic's tip is to wrap radiator hose with a little electrical tape where you attach the clamps. This should prevent the clamps from cutting into the hose.

 

The temp guage goes up to a little below the half mark and stays there. Never has it heated past that point and that's what confuses me. Why would this take almost a day to come back on. Now i'm not sure if it's the same error code, i'm just going with that since it popped on around the same time and point in my daily commute, which was about 12-15 minutes later.