Coolant Temp Sensor

[Dirty325ix]

My Coolant temp sensor is throwing a code and my car is overheating after 30 minutes of driving and once I turn the car off a large puddle of coolant spills out of my coolant reservoir but while all that happens I feel like the temp gauge in my car is working perfectly fine.

are they different sensors or when I look at my dash is it just full of lies

and does this sound like just a coolant temp sensor or could it also be the metal thermostat not working properly

[jlevie]

The gauge and DME use different sensors. There are three possible reasons for coolant venting from the expansion tank:

1) The cap could be bad and lifting at too low a pressure
2) The engine could be overheating to the point that the coolant is boiling
3) A head gasket leak or a cracked head could be pumping air into the cooling system

If (2) has or is occurring and the cooling system is not filled with plain water, the chances of the head gasket still being good and/or the head not being cracked are slim. In this case, my suspicion is that both the overheating and the venting of coolant is case (3).

[Dirty325ix]

what is causing the overheating is what I am wondering because the coolant was mostly water because I have just got the car running and didn't want to waist money on coolant that would leak out a hose and I have already experienced a bad head gasket that filled the coolant with excess pressure and that was way more aggressive than this this definitely caused by the boiling liquid

I was having trouble bleeding the system of air and the hoses all seamed soft
does something turn the water pump on maybe that is not getting turned on?

[Dirty325ix]

so it seems I was not done with filling the cooling system but it is taking a while to bleed it

[Pocket Chant]

I had a problem like this a while ago. Turns out the return line to the expansion tank was clogged. Check your hoses for blockages.

[jlevie]

what is causing the overheating is what I am wondering because the coolant was mostly water because I have just got the car running and didn't want to waist money on coolant that would leak out a hose and I have already experienced a bad head gasket that filled the coolant with excess pressure and that was way more aggressive than this this definitely caused by the boiling liquid

I was having trouble bleeding the system of air and the hoses all seamed soft
does something turn the water pump on maybe that is not getting turned on?

The cooling system isn't difficult to bleed using the procedure below:

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500rpm for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.

The water pump is driven directly by the engine, so it works as long as the engine is running. A bad thermostat or a clogged radiator are obvious possibilities for a hot running engine. Extreme difficulty in bleeding the system is usually a head gasket leak.