My advice as a previous owner of one of these cars is to RETURN it if you can happily! The factory used defective gaskets to seal the passages that the coolant runs through on the intake. They used a plastic that warps and causes leaks. I noticed this on my 2003 Malibu. I started smelling coolant when it was hot and noticed I was losing small amounts of coolant. The bad thing , as was the case with mine, is that these gaskets will also allow coolant to seep into the oil which in turn results in engine failure. And my problem arose at, you guessed it, 140,000 miles!Upon taking the intake off to fix the smell, I found that the gaskets were totally warped and useless for controlling where the coolant went. If you have a Lemon Law, I would strongly suggest that you return this junk heap as I have seen at least 5 of these cars completely disabled as a result of this issue. The V-6 in your car should not be running over half way for any reason! The one other thing it could be would be a faulty electric fan or the switch that turns it on. Either way, Those gaskets are a factory mistake a nd you will not escape repairing your car because of them. Do yourself a big favor and get your money back if you can.
ASE certified auto mechanic and previous, NEVER AGAIN, owner of an 2000 to 2003 Malibu.