Thermostat may be stuck closed.

[gokaipyro]

How would I go about checking to see if he thermostat is stuck closed. The problem with the car is it isn't blowing heat at all. After the car warms up and everything, no coolant leak either. I've been checking things off as to the cause of the no heat.


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[Smartdave]

If the thermostat was stuck closed I would think you would have overheating issues.

 

[gokaipyro]

Ok thanks. I shall cross that off my list.


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[Jaysonic]

Your thermostat is probably stuck open. That would cause it to not heat up the way it should.

 

[gokaipyro]

Your thermostat is probably stuck open. That would cause it to not heat up the way it should.

So how would I check to see it's working. Isn't it electronically controlled.

 

[WyrTwister]

First thing I would do is unplug the connector & see what that does or doesn't do .

Also , do the hoses to the heater core get warm / hot ?

Does it have a coolant valve controlling coolant flow to the heater core ?

Blend doors inside the HVAC box may be misbehaving .

But , yes , if the tstat is stuck open , you will not get much heat in the winter .

Any Check Engine Lite ?

God bless
Wyr

 

[gokaipyro]

First thing I would do is unplug the connector & see what that does or doesn't do .

Also , do the hoses to the heater core get warm / hot ?

Does it have a coolant valve controlling coolant flow to the heater core ?

Blend doors inside the HVAC box may be misbehaving .

But , yes , if the tstat is stuck open , you will not get much heat in the winter .

Any Check Engine Lite ?

God bless
Wyr

No CEL, and the inlet hose was hot near the thermostat, but cold near the heater inlet tube where it connects at the fire wall. I'm starting to think it may be clogged.


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[RMinNJ]

Sounds like it. Should get yourself an ultra-gauge so you can see the engine temperature.

 

[gokaipyro]

I have the auto enginuity scan tool. It shows my coolant temp. It is doesn't go above 223 F. If it's getting to operating temp wouldn't that mean the thermostat is working and also there isn't a code. I just hear how it isn't likely that clog could happen on a 2012. I'm see about flushing it this weekend.


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[gokaipyro]

so what would cause the engine to over heat when using the a/c

 

[rojoes]

so what would cause the engine to over heat when using the a/c

Is the radiator fan coming on at all ?

 

[gokaipyro]

Yea it still comes on, and I'm sure there's a slow coolant leak somewhere too. There is coolant in the tank as well.


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[rojoes]

Did the any throw any codes when you checked?

 

[gokaipyro]

P0597 after I tried unplugged then plugged the engine thermostat back in to test it. The is was about 15 ohms is that too much resistance?


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[rojoes]

Is it a plastic housing or metal housing thermostat unit? The plastic housing units are said to be more problematic as mine failed and had a slight leak. It could very likely still be under warranty anyway...Check with the dealer since the thermostat unit is around $100.000 let GM pay for it.


Symptoms of a P0599 code will vary depending on the position of the thermostat at the time of failure, however, it is unlikely that there will be any noticeable difference in the operation of the vehicle. The check engine light will illuminate and one of the above codes will be set The temperature gauge may read abnormally high if the thermostat failed in the partially closed position, conversely, it will read lower than normal if the thermostat failed in the full open position

Read more at: http://www.obd-codes.com/p0599
Copyright OBD-Codes.com

 

[rojoes]

GM electronic thermostat part 1
https://www.youtube.com/watch?v=6m6nJ1Xv8PU

GM electronic thermostat part 2
https://www.youtube.com/watch?v=Bs0QcLxFDWc

 

[gokaipyro]

Thanks so much dude. I'm sure it's the thermostat when I replace it I'll give an update.


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[gokaipyro]

I'm still getting the code p0597 after I changed the thermostat.


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[rojoes]

I'm still getting the code p0597 after I changed the thermostat.


Clear the codes, you can just unhook battery for 25 minutes

 

[gokaipyro]

Yea I cleared it then it came back on after I drove it around the block.


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