Guys I am new to this site. I just recently purchase a 04 Infiniti g35 sedan, after 4 month of owning it with 68 k miles the radiator cracked causing it to over heat. I took it to a local repair shop had the radiator replaced and new thermostat replaced as well I even replaced the cooling fan because the OEM fan motor went bad. My heater works I don't believe to have air in cooling system but for some reason my new fans run more then my other one did and on high after 10 mins of driving it's annoying. I took it to Infiniti they said everything is good my car seems to be working fine which I know it's not because before my repairs I never heard my fans before. I even replaced cooling temp sensor and still same shittt!!!! Plz help any ideas as!!!

 

Did you fix this?

 

Probably installed a different temperature rated thermostat (hotter thermostat) which is causing the car to spend more time with the fans running.

I prefer the 68C thermostat from the rev-up VQ35DE, not the ones for the regular DE. The rev-up opened at 68C, the normal thermostat opens at 76C. A lot of that is because of where I live though, my car isn't driven in the winter and we regularly hit 115F-120F here plus I was doing occasional track days.

The fans should be kicking on low at 208F, high at 212F. You can use an infrared thermometer and shoot the engine block right next to the engine temp sensor to get a pretty accurate reading to see if your car is actually running hot.

When the fan motors start to wear out they usually start to spin slower and thus push less air past the radiator, this will make the car switch to high speed fan quicker because it's not pushing the correct amount of air past the radiator.

A radiator that has some blockage won't dissipate heat as well causing the fans to work harder to get the coolant temp to drop.

Both of these things might be an issue for you.

 

I have the same issue as the OP.
-my G35 overheated
-replaced thermostat, but still overheated
-found that radiator was leaking and replaced
-no more overheating BUT
-the fans will be on high and will stay On until I turn off the car.

thanks for suggesting the original thermostat. I will replace it and see what happens!


I replaced my leaking radi

 

Does your HEATER blow HOT AIR?

If so I would pressure test the system, your fans should definitely not be running on high all the time unless you're really pushing the car.

Mine would kick to high and not go back down to low once our weather hit about 110F, anything under that and it would cycle back to low fan speed intermittently depending on how I was driving.

Also, anytime your AC is running the fans will be locked on to high fan speed.

 

Yes, my heater blows warm air. I believe air has been bled out of cooling system. I don't know what is pressure test. Do you have an instruction?

 

Just google something like "standt coolant pressure test" and see if any videos pop up. Lot easier to watch a video than to have it explained.

 

The coolant pressure test wasn't anything I didn't already know about.

Thanks, cleric670, again for suggesting the sensitive nature of thermostat. I swapped my new thermostat with the old factory installed one. Voila! The fan works normally now!