So its overheating. but only on occasion at idle. Now some days this happens sometimes at night in all diff tempatures. the water pump was replaced 1k miles ago. radiator is fine with a dual fan. used to be a single core single fan. whats wrong?

 

Fan kicking on? Check the coolant level after the pump was installed? Does it seem like it takes a while for it to warm up?

 

Did you purge all the air out of the system?

 

both fans worked checked those plenty of coolant. and its run for about a yr on this radiator and new pump without problems till now.

 

What about the radiator cap?

 

u mean the thermostat? or the radiator cap itself?

 

The actual radiator cap. You can check to see if the thermostat is opening by starting up the car with the rad cap off. When the thermostat opens, you should see flow.

If your cap is bad, it can cause overheating issues.

Your radiator could be plugged/clogged as well.

 

ok so thermo is new. i let it idle till it started to get hot. no fans r comin on. those are dead now. how can i check to see if its a relay fan motor or the thermostat for the fan?