2008 Suburban with 5.3 GM motor in it. Just in the last few days it's been very slow to warm up and doesn't ever get to the 210-degree mark on the temperature gauge, where it normally runs. It's been running about 195 to 205. Any experience I've ever had with a car not coming up to temp was fixed by a new thermostat. But before I tear into it, I wanted to check here and see if anyone had any other ideas what is causing these symptoms. Also, I've used Stant thermostats before with good success. Any other suggestions or brands to stay away from, assuming it is a thermostat issue? Thanks a lot.