Hello, I have a 2004 G35 sedan and it just started to overheat. The coolant has been changed and system bled a month and a half ago and my heat inside the car is good, The first thing i notice was the fans are always running like its actually overheating but stay at the normal temp looking at the gage and now while the fans are running the temp gage slowly creeps up past the registered line on the gage. I'm trying to figure out if there's any issues with the fans, Thermostat, water pump or maybe a coolant leak. What should i test to figure out the problem? Thank you

 

Start the car up and keep your hand on the top hose to see if the thermostat opens. If the hose gets hot and is cycling like it should turn it off in a quiet garage and listen for any hissing. Check between the radiator and AC condenser to see if there is debris like leafs/grass/dirt restricting air from flowing through.

Just a couple things I can think of off the top of my head. I just had this problem on the 04' and it was a crack in the plastic tank on the radiator and also had tons of crap between the radiator and condenser that had to restrict the airflow quite a bit.

 

It looks like i found the issue, I just opened the hood and the pics show coolant spraying from the top of the radiator along the seams. There was a smell of coolant when the fans was running and the running fans was spraying coolant all over the top hose and all the along the fan area, I didn't notice any leaks from the thermostat, Hoses or water pump areas. I had a Acura and the same thing happened when the radiator was failing...Thanks for replying

 

I wish all car problems were this easy to diagnose. Glad you're able to get this fixed, if you haven't purchased new hoses it's a good idea to replace them with the radiator while you've got it all apart. As inexpensive as they are this seems to be a no-brainer to me.

 

I agree, It was a easy fix and when i accelerate the pressure from the cooling system would spray coolant everywhere and i also notice my reservoir bottle was low from the leaking radiator, I don't know if the radiator was ever replaced or if it was the original, As you can see it have a genuine Nissan radiator. I will also take a look at the hoses and other cooling parts when i remove the radiator...I flushed the cooling system about 2 months ago using Nissan blue coolant so i can reuse the coolant and i have the Lisle spill free funnel to help with the long bleeding process...Thanks again

 

Be sure to research how to bleed the coolant system. The process is a pain but you will overheat if you do it wrong.