General Maintenance & Repairs - temp gauge issue?

My car usually gets up to 210-220, once warmed up and stays there, I hear the fan kick on after driving for longer then 20mins and coming to idle and then it keeps turning on and I see no fluctation on gauge, I also feel like motor starts to stuggle and lose power, could I be overheating? And gauge not working?

You are gonna lose power at higher temperatures. The stock tune has your fans coming on at 215*, if I remember right. So the fans kick on at a certain temperature and then kick back off below another temperature.

The gauge isn't going to give you an exact reading of the temperature b/c it's located in the block and the ECT that the PCM uses is plugged into the water pump so they're going to read differently. It's probably working just fine. Just need a 160* thermostat and a tune to have the fans kick on at a lower temperature if you're worried about it. I would recommend it b/c running at cooler temperatures can extend engine life.

On '99-02 cars, the gauge doesn't really move once you reach normal operating temp. It will show about ~210° any time that the actual coolant temp is about 190-230°F. It's normal to hear the fans cycle on and off without seeing any movement in the gauge on a '99+ model.

Would I benefit from an aftermarket radiator with 160 Thermostat? Motor has 150k on it and reason I'm asking is cause I live in south Texas and its hot almost all year round, stays in 90s, 100s + summertime

Stock radiator is gonna do you just fine. If you have an LS1 car, put an LT1 radiator in it. 160* thermostat is gonna help some but not a lot. You're gonna have to get the PCM tuned so the fans turn on at a lower temperature to really see a difference while you're idling. When I drive around, my temp stays around 190, but if I sit there and idle, it jumps. Also, check that your air dam is intact.

Why's lt1 radiator better?

Thicker and cools better. It also has an extra hole on the bottom driver side that the LT1 uses but the LS1 doesn't. So you just put some hose on it and plug the end of the hose and then you have a drain that works a lot better than the factory drain.