Overheating and Check Engine Light

[Acilec]

Ok. So 3 days ago a had a spike in Engine Temp. so i did a little bit if diagnosing and everything pointed at a bad thermostat. So I drained the coolant, removed the old thermostat and tested it in boiling water to see if it opened. It Did Not.
I went and bought a new one from Advance Auto and installed it. Filled my radiator back up with fluid and took it for a test drive. IT STILL OVERHEATED!
So I returned the new thermostat, bought some liquid gasket and sealed the thermostat housing back up with nothing in it (using the liquid gasket to seal the housing).
The Engine temp is pretty low now (which is what i was expecting) and I have been running it with no thermostat for the last 2 days. On the way to work this morning my Check Engine light came on. I plan on putting in a thermostat from NAPA today.
Will this turn off my check engine light?

whew... that was a book...

Any body have any ideas??

THANKS!
-Jesse

 

[BOOSTR]

While you were diagnosing the the situation did you hear the cooling fan kick on before the temperature climbed above normal? Quite possibly the sensor that signals the fan to come on is shot and that is why you are overheating.

Get your code read and fix the problem. Don't risk ******* up the cylinder head by driving around with the temperature in the danger zone. In addition to putting in the new thermostat you might want to get a new radiator cap as well.

 

[MS3_KIDD]

x2 on finding out the DTC

double check cooling fan opperation, under what conditions was it overheating?

could also be the water pump

 

[Acilec]

reply

How do you get the code? I didnt know there was such a thing... probably would have been helpful.

As far as the fans go. I noticed that the Bigger fan (drivers side) turned on appropriately. The Passenger side only turns when the AC is on. Is that normal?

It would overheat after 5-10 minutes of normal driving conditions.

I assume its not the water pump because when the thermostat is out (removed) the coolant circulates through the engine (low temp reading).

 

[BOOSTR]

You need an OBD-II reader or to go to an AutoZone and they will do it for free. That's good that the fan came on and yes its normal for the AC triggered one to come on when the AC button is pressed on.

Put in the new t-stat and try and get your code read.

 

[MS3_KIDD]

How do you get the code? I didnt know there was such a thing... probably would have been helpful.

As far as the fans go. I noticed that the Bigger fan (drivers side) turned on appropriately. The Passenger side only turns when the AC is on. Is that normal?

It would overheat after 5-10 minutes of normal driving conditions.

I assume its not the water pump because when the thermostat is out (removed) the coolant circulates through the engine (low temp reading).

normal driving as in city? highway cruising?
also do you have any mods?

 

[Acilec]

City driving for about 10 minutes will get the engine temp up.
Only mod is an intake.

Also, is there a certain way to fill the radiator to get rid of any air pockets trapped in the system?

 

[TheMAN]

the code is probably the one for "thermostat stuck open"... which it is because you don't have one!

you need to fill the radiator SLOWLY to get the air out and run the engine for a few mins with the cap off

if the radiator cap is bad, it can also overheat

if you drove too long with it overheating the first time, you may have blown the head gasket and that will also cause further overheating problems

your fans are working normally

 

[Acilec]

The error code was something about the engine temp being cooler than the thermostat was regulating. makes sense, i dont have a thermostat.

Napa was closed by the time i got home today. ill get the new thermostat tomorrow after work.