Pontiac GTO 2004-2006 - Bad T-Stat

Yesterday i got some goodies delivered. My Vararam intake 160 T-Stat and my O2 extentions So i can get my headers put on. Well I put my stat in and my car is still running hot. Its been running around 195-200. I know its hot outside but that seems like its running like stock?? What should it be running around

With my 160 stat, the needle stays between the 2nd and 3rd line I think thats around 160-170 maybe. I dont know how to check my numbers exactly. Thats were my needle always stays at on normal days. never been on or past half.

I know in extreme heat (like in AZ) 160 T-stat's are too cold. And are pretty much the same as running no thermostat, as the coolant doesn't stay in the radiator long enough to pull the heat out.

Unless there's something else wrong, did you flush the radiator or coolant system? Maybe an air pocket?

The fans don't come on unless it hits a certain temperature. You need to adjust your fan settings in HPTuners to take full advantage of a T-Stat. It's not like a belt driven fan that's always going to be pulling air through the radiator.

You can run the car with no thermostat, but if it's hot outside and there's no air moving through the radiator it's not really going to effect the temperature much other than the extra flow from not having the thermostat.

I have a 160* stat in my 05 and on the freeway cruising my temp is about 173*
Yet sitting in traffic I see temps close to or over 200*

iirc 05-06s you cant alter the temp when the fans turn on, but you can alter the intensity of the fans once they are active.

As long as your cooling system is doing ok, your cruising temp should be lower than with the factory stat as that is around 186* or so. But once the vehicle stops moving your temps will climb until the fans turn on and maintain the temperature at the set points.

Aside from that, just make sure the system is purged of all the air, and you should be fine.
--Glenn

i believe a 160 t stat starts opening at 160 and is fully open at 180 degrees. and as mentioned the fans need to be adjusted to help at slow speeds

Yeah i drained all the fluid out and i made sure that i got all the air bubbles out. I ordered another stat to see if it runs any cooler.

When are you checking temperature? Your car will run the same temps at idle without adjusting fan speeds/upgrading fans. Take it on the highway and set the cruise for ~10min and see what the temperature reads. My Vette has a 180 T-Stat, runs ~176 on the highway regardless of outside temp (even when it was 100deg outside it was still 176-180 on the highway), but due to stock fan settings it runs around 200-205 when sitting still.

Yeah i drove around for 2 days and took some long drives and it is running like a stock t-stat

You need to adjust your fans to take advantage of the 160 stat. It will NOT run cooler all by itself. Keep in mind that too cool is as bad or worse than too hot.

Yeah i drove around for 2 days and took some long drives and it is running like a stock t-stat

You checked it after driving ~10min with the cruise set while still moving and it was the same temp? Your cooling system might not be efficient enough to take advantage of the lower t-stat. What are you running for a water/coolant mix, and did you use distilled water? What are outside temps like? There's a lot more to making a car run cool than just swapping out the t-stat.

You checked it after driving ~10min with the cruise set while still moving and it was the same temp? Your cooling system might not be efficient enough to take advantage of the lower t-stat. What are you running for a water/coolant mix, and did you use distilled water? What are outside temps like? There's a lot more to making a car run cool than just swapping out the t-stat.

Yeah it was a 50/50 mix and it was like 90....my daily is a 2000 Grand Prix GTP that has a 180 stat and even on hot days with the a/c running it stays around 180

So your reason for the new stat was what?