hey guys i been having problems with my G35 overheating already changed fan clutch and thermostat after these changes it worked fine for like 4 days and then it overheated again it not leaking coolant or anything i ran it with out the thermostat for like a week and ran fine and when i decided to put on the the new thermostat it started heating up what can the problem be

 

Stupid question, but did you put the thermostat in upside down?

 

Test the thermostat...I've had a couple fail right out of the box