So I have an interesting issue on my hands. I found this thread, but there was no resolved typed up.
https://montecarloforum.com/m_18511/tm.htm

Here is my problem:
A few weeks back the low coolant light came on and would stay on for about a minute longer than in should. I just had the intake gaskets done along with the water pump and thermostat. My friend, who worked on the car, said that a lot of times the coolant level sensors trip once and they need to be replaced. Well it goes off so I'm not worried about it. Well one day, I needed to put about 5 oz of coolant into the radiator and I topped off the overflow to the cold line. That was about a month ago. I've put in probably 20 more oz since then and have topped off the overflow too. I'm not leaking any fluid, and I'm not burning fluid, and it isn't going into the oil or the cylinders. I pulled all of the plugs and they look great. (They better look great, they've only got 3k miles on them. lol) Well yesterday my car reached operating temp (195*) VERY quickly, like, within a mile, and then it reached about 220* and then dropped back to about 185* where it runs when I'm driving. I have a 195* thermostat in it and it rarely reaches that temp, unless it's hot outside and idling for a long time. My thoughts are either an air pocket, or my radiator is possibly getting plugged...What are your thoughts about it?

 

Air. I'd bleed the system with the Heater on full-blast to get the coolant circulating all through the whole system. Because if you aren't chewing-up coolant or seeing a sign of a leak ... it must be finding a void to fill someplace.

I called Chevy and got them to tell me about DexCool. They said leave it in and gave me a Reference Number and a name of the telephone agent who researched my car. I logged it into my maintenance record on "My Chevy Link" so if there's a problem I have someone to blame.

 

so what is the verdict on dex cool, GM says leave it in and most mechanics say to get rid of it?

 

bleed the system sounds li8ke it has air in it.

 

Thanks for the advice. See my car doesn't apply to the settlement because it's too old... lol. I personally would still bleed the system, but I'm coming from the angle of, I don't have the money to fix it, even if I was to get reimbursed. lol. The ONLY reason I could afford to fix mine at the time was because of financial aid from college. lol. Good luck though!