need help

[Beasty306GT]

So i was driving last night to a car show the temp read 180 when driving...but then when i got into stop and go the temp started climbing to 210+..it didnt do this the whole time before even on the dyno it stayed under 190 thw whole time...but i recently changed my heater core could that have something to do with it? its a 180 t-stat new aluminum radiator also new engine with all new parts ...just wondering what u guys thinik..could it be air in the system? its also a 306 so its bored over and on the drive home it was nice a cool out the car ran at 170-175 the whole ride home like 20 min ride...stock fan and shroud

 

[HISSIN50]

I'd take a look at the fan (for cracks) and the fan clutch (wear). The clutches can lose RPM over the years.

 

[Beasty306GT]

how can u tell if the clutch is bad on the fan?

 

[steelie4u]

i have whats in my signature and i had to upgrade to a electric fan cause the clutch fan just cant keep it cool, i tried everything before i switched but now it runs 180 the whole time no matter what, i used a Mark VIII fan

 

[885ive.0]

How long has it been since you replaced the thermostat?it could be sticking

 

[Beasty306GT]

thermostat is brand new 180 motor only has couple hundred miles on it..i did relize now that i think i put the thermnostat in backwards...but why all of a sudden would it get hot at idle and didnt when i let it run before the heater core replacement

 

[885ive.0]

The heater core should make it overheat because it doesnt have anything to do with the water going in the water or cooling the water but if the thermostat is in backwards thats problem and are you sure all the coolant lines were hooked back up in the correct place after installing the new heater core

 

[Lawbreaker5.0]

If you put it in backwards you would instantly overheat. I would think you have a bubble. I always pull the temp sending unit and fill it up behind the thermostat.

 

[885ive.0]

I meant to say shouldnt