Check engine light on now

[maxim1157]

Okay,I was working on my 2010 Aveo replacing the thermostat assembly and now the check engine light is on. I topped off the reserve tank for the radiator with Prestone, don't have the GM dexcool..wouldn't think that would matter.. is it because I have air in the system now by taking apart the thermostat assembly? If so where and how do you bleed the system. Thanks

[slayerized6]

Remove radiator cap/reserve tank cap before starting the car and let engine get up to temp. There is no radiator cap on the Aveo (at least on my 2005, but the reserve cap is pressurized). You will hear the system "burp" a few times; this is air escaping the system. Also, invest in a code reader; it will tell you exactly what is wrong. Did you unplug any connections and forget to plug something back in? I doubt a code is popping for air in the system.

On a related note, it is not advisable to mix Dexcool with the 'green' antifreeze. Those two coolants together will turn into sludge within your cooling system and cause massive problem. I suggest you get your cooling system flushed immediately.

Can I Add the Green Coolant to the Orange Coolant?
Dexcool mixed with Antifreeze (green stuff) - LS1TECH

[maxim1157]

I'll try that with removing cap on reserve tank. Yes I unplugged the sensor to the thermostat assembly, but plugged it back in. I plan on flushing the system and using just one coolant when I get the new thermostat assembly I ordered.