This is the second summer now that my car is running hotter than normal. It used to always stay below the first tick mark with my 160 degree t-stat and csi electric water pump. I noticed today while sitting in traffic that it climbed a little over the first tick mark, and then dropped down to and stayed at the first tick mark while going down the highway.

The pump and hoses are fairly new, but the t-stat is a hypertech that is 10 yrs old now. The radiator and recovery tank are ok and clean, and there are no leaks. The coolant is only 2 yrs old and I am running a bottle of water wetter too.

Where should I start investigating?

 

Check the thermostat first, since its 10 years old.... Boiling water and a thermometer..

 

not that much money just get a new one, i have the same one in there. 160 and now and then in traffic mine goes rite up to that mark.

 

Is the fast fan kicking on when it gets that hot? It should kick on and keep it below the first tick (that's if you have the hypertech or something set to turn them on).

Hal