If you are sitting in traffic in hot weather you may notice your coolant temperature going up to 210 degrees or higher.  Most new owners of a Buick Reatta panic when they first notice the temperature going up so high. It is normal for the 3800 engine in the Buick Reatta to go up as high as 220 - 230 degrees. What causes the high temperature is the ECM was programmed at the factory to turn on the main cooling fans at around 220 degrees allowing the engine to get very hot before cooling the engine back down. The 3800 is designed to run at the high temperatures and should not be damaged by temperatures in that range. Many Reatta owners have changed the stock thermostat to try to lower the temperature. Although that may help, the problem will not be solved without reprogramming the chip in the computer to turn on the fans at a lower temperature.

Warning! Never remove the radiator cap when the engine is hot. Personal injury could result.