Need help

I have a '03 G35 sedan that started overheating a few weeks ago. The first time it did it, I was a several miles from home so I cranked up the heater and rolled the windows down. The temperature gauge went back down once I got up to highway speed. The heater took a long time to get hot. Every time I slowed down or stopped the temperature would go back up.

When I got home, the coolant level was down and the reservoir was full. I filled the coolant back up and took a short trip - the temperature gauge went up after driving for a few minutes.

I finally got a chance to look at it today. I started it and let the temperature gauge get up to the below halfway mark while idling. The main belt driven fan looked to be working fine. The electric fan in front of the driver side never came on/ never started turning. I am no mechanic, but I am assuming this is the issue?

If so, has anybody changed this fan before i.e. is it a simple job? I can do most minor work myself, but usually I can find a step by step or youtube video. I haven't seen one specifically yet. Any help would be appreciated.

 

Any codes? Could be a temp sensor issue not causing the fans to kick on. Could also be a bad thermostat or air in the system.

I would start by trying to bleed the cooling system. https://g35driver.com/forums/g35-cou...ng-system.html

 

if any of the radiator hoses feels limp or not pressurized when the temp gauge is halfway then you have a problem and bleeding will fix it (provided the air isnt able to get back into the system through a leak afterwards)

 

Could be electric fan motor not working.

G35 Electric fans have a high failure rate.

Remove Electric fan motor harness plug and check resistance.

 

If you haven't loss coolant or just had your coolant replace, I would start with the fan. I would bleed the system just yet. You should be able to jump the fan to see if it's the problem and go from there.

 

Failed electric fan was my problem too. New motor (about $80) and about 10 minutes was all it took to replace it.

 

There is a tsb on the fans I got something from Infiniti about it..

 

03 Sedan means you have a fan clutch...

the electric fan in the front is an auxiliary fan meaning it only turns on for certain events. In example:

A/C ON
205 TEMP with AC off turns on at 50% power
215 temp with ac off turns on at 100% power.

If you are experiencing the reservoir full under highway speeds but the engine cold and the radiator empty then your engine is TOAST you need a new head gasket. The engine can self bleed itself but it takes FOREVER! But when the engine is under consistent load the thermostat opens and closes continuously thus providing even pressure which will open the cap and self bleed itself. Just in the mornings you'll open the reserve along with the radiator and all the fluid be missing.. Keep filling until you notice everything is great.

If you have a fan clutch I suspect you do... chances are that it is worn out and it's no longer functioning properly. You need to test it and if faulty you can replace it. But if under highway speeds the engine is spitting out fluid chances are the head gaskets are done. You'll change the simple stuff first it's the right thing to do... like, Radiator Cap, Thermostat, Bleed the system, Fan clutch.... then youll notice
it's still doing it... at that point youll have no other choice but replace engine and/or headgaskets.

 

faulty fans or thermostat

 

+1 Eric, couldn't have said it better myself

 

Update:

Thanks for all the responses. I changed the electric fan motor, burped the system per the procedure, and also replaced the thermostat. Still overheating and heater not working.

I was idling the car and waiting for it to get up to midway on the temperature gauge when I noticed coolant drip coming from somewhere above the radiator fan. After close inspection, it looks like coolant is leaking from the top of the radiator where the aluminum meets the hard plastic not far from the cap.

Again, I am no mechanic but I think that is my problem.
Has anyone heard of leakage in this spot on a 2003 G35? Just seems like a weird place to fail.
Also, I have some time before I need to drive the car and was debating on changing the radiator myself - anyone have any experience with this?

Thanks again!

 

Sounds like where I had a leak years ago on another car. A spot where 2 materials are attached seems like a likely failure point.

 

That's the same spot the rad on my I35 failed just over a year ago. Replacement was straight forward on the I. Can't see it being too much different on the G.

 

Recently noticed the temperature gauge creeping up while driving yesterday, and then eventually got really high. Turned on the heater with windows down to drive home. This morning I checked the coolant level and it was between minimum and maximum, turned on the a/c and both fans were running, after driving a little, I noticed the coolant level was well above maximum. Didn't notice anything leaking, but as soon as the fan comes on, it doesn't shut off until I turn the car off. Bringing it into dealers later this week, but wanted to see if anyone had the same symptoms/issue and know what it could possibly be. It's a 2006 sedan BTW!