hey guys found that my Z was overheating again last night (i had this problem before but found out it was a cracked radiator and we replaced it with an aftermarket) i already bled the system and everything n it was still overheating.

now i found a hole in the lower radiator hose and that should explain the overheating. past few weeks ive been losing coolant and i added more coolant to the reservoir and the car was not overheating however the A/C wouldnt blow cold air unless the engine was revving and the heater would not blow hot air unless the engine was revving as well. my question is is the hole in the radiator hose the cause for the A/C and the heater to not function properly? its odd that the car didnt overheat when i put a lot of coolant in the reservoir but once the reservoir was empty it started to overheat but in both cases the a/c and the heater did not function unless the engine was revving. any inputs or suggestions guys? thanks.

 

First of all, REPLACE THE COOLANT HOSE ASAP! A hole will become a rupture if you keep pushing your luck, and the system may have a hard time maintaining the correct pressure when you have a leak in the cooling system... the lower the pressure, the lower the boiling point of your coolant. Check to make sure that both of your cooling fans are coming on, it is pretty common for one of the fan motors to go out, in fact Nissan extended the fan motor warranty for 04-06 cars. With the AC turned on, both radiator cooling fans should kick on, if one of the fans does not come on you either have a bad fan motor or relay/wiring to the fan motor. There must be airflow through your AC condenser in order for the AC to cool properly, so if the car is not moving and the cooling fan is not working properly the AC will not work as it should. It is NOT odd that the car starts overheating when you allow the overflow tank to run dry... when this happens the cooling system starts sucking in air and air in the coolant leads to overheating and the heater not working properly.