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Great follow-up! (y) Hope the situation stays resolved. There's a lesson to be learned that mixing fluid types can produce adverse effects and complicate an approach to the problem.
+1. My son's first car was a '96 Camaro. Some previous owner thought it a good idea to mix traditional green coolant with Dex Cool. That creates quite a mess in the cooling system. Took multiple flushes to clean up the mess.
 

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2012 Acadia SLT AWD
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Discussion Starter · #22 ·
Great follow-up! (y) Hope the situation stays resolved. There's a lesson to be learned that mixing fluid types can produce adverse effects and complicate an approach to the problem.
Definitely! The was the second time I flushed but the first time was only after couple hours idling using BLUEDEVIL radiator and oil flush. This time I just used the standard BLUEDEVIL radiator flush and ran it for 200 miles. I believe the higher engine speeds helped breakup the gelled snot in cooling. Honestly this was the first car I have seen that had this type of reaction in coolant. Heard about but first personal experience.
 

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2012 AWD having some cooling issues. Started when I was towing jetskis but now all the time. No codes present. I have replaced all relays, cooling fans, radiator and cap, thermostat, water pump, both hoses, engine temp sensor, added large external trans cooler, and checked/added refrigerant. (HD Radiator and trans cooler were to make towing better indirectly related.) OBD reader and it shows the computer is not commanding any fan until it hits 220 degrees and that is only low it won't command high. Started about 6 months ago. Strange thing maybe not related but on OBD shows ambient temp stuck at 75.2 degrees but dash display shows the actual accurate outside temp Any ideas?
That is all correct. ECM commands Fan relay 1 to turn on at 225F. This closes the circuit to run both fans in series running them at a split voltage for low. When the temperature comes back down to 200F, the fans should turn off. This is proper function. When turning on the A/C the low speed is triggered according to the pressure switch in the A/C system, not just always on. The ECM only sends for the high speed fan if the temperature sensor reads above 230. Then the fans are both given full voltage to run at full power.
 
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