I have a 97 Z/28 a few years back i installed a 160 thermostat and hooked the seccondary fan on a toggle switch and you could let the car idle in the staging lanes with the fan running it would never go over 170 with the fan running out on the road same thing 170, Now the car out on the road runs 170 on level and on a hill now it starts to heat up and with the car idleing now it goes up 200 to 225 could this be because of a stopped up radiator or could it be one of the fans not kicking on i noticed it was running about 200 degrees and neither fan was working and i fliped my toggle switch on and it realley didnt help it much anyone know what it might be. Thanks

 

What kind of shape is your air damn in? when check the front of the rad. for debris. When was the last time you cleaned and flushed the rad?

 

As far as i know its never had anything done to it. The car has 117000 miles on it.