G35 cooling fan

[mb32]

I'm trying to figure out the cooling fan operation on my 2006 G35.

I believe when the A/C is switched on both cooling fans should engage on low speed. I seem to be getting strange operation from my fans.

The driver's side fan wasn't working at all. I checked the wiring and rotated the fan and it spins freely. I turned the A/C on and low and behold it started to work.

Now both fans seems to be working but they are cycling on and off for about 5 seconds when the A/C is running. Is it normal for the fans to cycle on and off even with A/C engaged? The A/C compressor is running continuously so I would think the fans would staying running as well.

 

[hyperscion]

has the water temp been running hotter tan norm? if not check the battery, a bad cell in the battery can cause wonky stuff.

 

[CBR.worm]

There was an extended warranty for engine fan issues on '06 G35's. Mine failed at 96k miles, the issue was that one fan didn't work at high speed. It might be worth looking into.

Beyond that, if you can get a copy of the service manual (they are floating around in .PDF form) it explains exactly when the fans should do what, including fan speeds relative to temperature and ground speed and other conditions.

The fan speeds do change based on A/C system pressure. Mine run at low speed for about 1 minute and then stay on high for the rest of the time the compressor is running.

 

[mclasser]

Originally Posted By: CBR.worm
Beyond that, if you can get a copy of the service manual (they are floating around in .PDF form) it explains exactly when the fans should do what, including fan speeds relative to temperature and ground speed and other conditions.

+1 On my I35, the FSM has graphs detailing the operation of the fans -- they have low & high speeds.

 

[mb32]

Originally Posted By: CBR.worm
There was an extended warranty for engine fan issues on '06 G35's. Mine failed at 96k miles, the issue was that one fan didn't work at high speed. It might be worth looking into.

Beyond that, if you can get a copy of the service manual (they are floating around in .PDF form) it explains exactly when the fans should do what, including fan speeds relative to temperature and ground speed and other conditions.

The fan speeds do change based on A/C system pressure. Mine run at low speed for about 1 minute and then stay on high for the rest of the time the compressor is running.



You're right. Looks like the fan motors do go bad but since I'm well past any warranty extension looks like I will be replacing these on my own.

I reviewed the FSM and it states that both fans should come on low with the A/C operating and high once temp or A/C pressure reaches predetermined threshold. Both my fans are coming on intermittently with the A/C on.

I think I'm going to just go ahead and just change both fan motors for peace of mind since a replacement fan motor is only $40.

I wonder how much disassembly to get access to the fan motor and if I have to take the entire fan shroud assembly off to replace the motors?

 

[Johnny2Bad]

Usually there is one fan that comes on whenever the A/C is operating, and a second fan that is controlled by the coolant temperature thermostat. So, it's normal if at idle one fan operates with A/C on and none with A/C off, or both with A/C on and one or both with A/C off. Sometimes the fans are two-speed as well, so they might operate at different speeds

Once again, we have a question that is vehicle-specific, so should be asked at a G35 forum, not BITOG. I guarantee you will find answers there, because every single vehicle on the planet has, at one time or another, cooling issues, so the search button will always yield results.

You can investigate further with a Digital Multimeter (DMM) but if the above checks out and you are not overheating in normal driving conditions, you probably don't have an issue.