[child_of_fire]

i have a 2003 impala 3.8L motor with a 180 degree thermostat in the car. normal operating temperature is usually 185-200 depending on the outside temperature and what kind of driving i am doing. but with the ac on and lately with the very hot summer weather while driving in stop and go traffic the temp gauge will hit about 215. does this behavior sound normal? i realize its only a 15 degree increase but it only seems to happen when its really hot out. the vehicle has a lot of miles on the motor and i'm just trying to gauge its cooling capability and make certain everything is working properly. the vehicle is very well cared for.

 

[kingnutin]

Are you going off the gauge in the dash, or an actual thermometer in the engine bay? You shouldn't be seeing temps anywhere near that high.

 

[DrewImpala]

Check the stat and make sure it's not clogged. Dexcol tends to gel up sometimes when not maintained. Check to make sure both fans turn on at higher temps. Check on the fins of the radiator to make sure they are clear of dirt, trash and bugs. And also check you coolant mix ratio. Most find that a 70dex/30water mix works better in hot areas. I had the same problem for a while.

 

[child_of_fire]

Check the stat and make sure it's not clogged. Dexcol tends to gel up sometimes when not maintained. Check to make sure both fans turn on at higher temps. Check on the fins of the radiator to make sure they are clear of dirt, trash and bugs. And also check you coolant mix ratio. Most find that a 70dex/30water mix works better in hot areas. I had the same problem for a while.

i'm going by temps off the cluster gauge. thermostat is a new 180 degree stat, both fans work, radiator is clear, maybe just a little old.

 

[kingnutin]

I would verify the actual temp with an infared thermometer, it could just be the temp sensor.