Really? Cuz I used to have a truck that I installed a manual fan on and the only time I turned it on was when I was stopped or going very slowly.

It was also on an episode of top gear (American version) where they were driving thru the desert, one of them lost a challenge and he had to remove his fan belt, making the fan useless. He had no problems at highway speeds.

 

Pretty sure highway wind gusts would probably be stronger then the fans.

 

Exactly.

 

No way... you are absolutely wrong.

Electric cooling fans are mostly off in all vehicles when the temps are below a certain point or if you are moving over a certain speed. This is real obvious to anyone who rides a motorcycle since the fans are directly below your tank and you can hear them come on. They come on only when you are in traffic and the coolant temperature rises above a certain point... typically 212-223 degrees Fahrenheit, depending on the bike.

Mechanical fans (on vehicles equipped with those) mostly will be on whenever the motor is running because they are driven by the main serpentine belt and are usually not attached to a clutch, but just about every electric fan in any modern car will not be on when the vehicle is moving above 35-40 MPH.

 

Here are two links that describe the operation of electric fans in both early and newer vehicles.

http://www.aa1car.com/library/electric_cooling_fan.htm

http://independent.co.ug/society/mot...nning-all-time

 

Well from my experience thus far dealing with this issue, I've been having to use the G35 to drive to school every day which is about a 40 mile highway commute from my home. Although I still haven't been able to replace my fan motors yet, the car has been running well on my way to school and the temp gauge has been stone faced just below the middle point (as a result of the 60+ mph wind gusts like you guys said). Its not until I start to drive around for parking on campus that I start noticing the temperature increase because of the slower movement.

But thankfully it doesn't increase to the point of hot temperature as it used to. Putting more coolant in the reservoir solved that issue already. But I will definitely have to replace those motors because life doesn't tell you when you'll get stuck in dead-stop traffic haha. Thanks for the comments and suggestions guys.

 

smh.... lol ok well you can think what you want. but your fans not moving while at speed will block more air than they let through. they are running while at highway speeds i can assure you.
thinking that they dont need to and manually turning them off during highway speeds, doesnt mean they dont need to be running. it just means you turned them off.
american top gear is a joke and a tv show. that offers little to 0 real world knowledge about cars. the only thing worthwhile on that show is Tanner foust, and he is a driver. not a mechanic.

coming from an actually racing backround and doing everything involving in cars top to bottom for over the last 10 years. im confident in telling you. you need your ****ing fans on and moving, even at highway speeds.

i understand while moving you are getting good wind movement. but pushing air through tiny holes, is a completely different story than pulling it. air will take the path of least resistance. and if you think even for a small second that air will travel through your opening in your bumper, through your ac condenser, then through your radiator. instead of going under, over, and around your car? you super high and dont know how air or wind travel works.

 

most motorcycles are air cooled and have the engine open and out to the world where wind and air travel effect it much differently than in a car. hahaha is this seriously a conversation we are having...

and NO, your fans are not off over certain speeds. once it hits its operational temperature. they are on. it doesnt matter if its 5 mph or 100 mph. in a car just to be clear. a motorcycle is whole complete different question.

 

hey thats a neat read. but we are talking about the g35 fans.
and ill wait here while you research how the g35 fans work.....

i honestly wasnt aware some top end brand new vehicles were starting to use speed sensors to kick them down to a lower speed. but its clearly stated, that over the temperature sensor when its supposed to kick the fan on, its still on, even at speed. it might be less due to the more efficient air flow. but they are still going to be on over temp.

 

"Most motorcycles are air cooled" is a blatantly false statement. No modern performance bikes are air cooled. Basically just Harley Davidsons (most of them) and some other American-made chopper style bikes are air cooled, but just about everything else modern is watercooled. Even modern dirtbikes are watercooled. And guess what... no dirtbikes even have fans because you don't need them when you are moving. Air doesn't directly hit the motor on a sportbike because it's covered by a fairing and also blocked by the front wheel, fender and nose fascia.

I just checked the Factory Service Manual and here is what it says about the cooling fan on page EC-120 for a 2004 G35 Coupe (straight from the manufacturer's specs):

FAN STATE: COOLANT CONDITION
OFF = Engine coolant temp < 201 deg. F
LOW = Engine coolant temp between 203 and 210 deg. F
HIGH = Engine coolant temp > 212 deg. F

http://www.nicoclub.com/FSM/G35/Coupe/2004/ec.pdf

I use an OBD-Link MX real-time engine monitoring tool on my G35 all the time and the coolant temperatures while moving over 40 MPH are never over 191 degrees, which means the fans are always off in that situation and basically anytime you are moving at highway speed. FACT.

End of Story.

 

Just cuz TG is a joke show doesn't mean it didn't happen, and I was just using that to support my very real world experience. Remember? My manually operated electric fan I talked about?

And what do you mean the fans black the air? The fans are behind the rad..meaning they're after the fact. I promise you that you get plenty of air at highway speeds for the fans to not be needed. OP just confirmed this as well.

 

andrewvk, I was out of town and couldn't respond, did partyman66 clear it up for you with the service manual reference he provided? The same reference is found in my 2003 manual EC-123. Do you now understand how the G35 cooling fans which of coarse is what we are talking about work?

 

yes the fans turn off and on with HEAT. THEY DO NOT TURN OFF AT HIGHWAY SPEEDS.


I get that you are getting more air once you are at highway speeds, but just because you are going faster doesnt mean they turn off.
they run once they are warm enough to get kicked on. our g35 fans have nothing to do with speed.

its CLEARLY POSTED. by the guy trying to prove the wrong point two post above you.

 

comparing motorcycle cooling to car cooling isnt even in the same sport of comparisons.
no ****ing duh bikes can be air cooled at speed. the engines are out in the open to the world.

and again, i stated that on our cars. the fans are NOT controlled via speed sensor. so thank you for posting up the correct information that i have already said.


bottom line, if you think you can shut your fans off because you are on the highway. you are wrong. sure you might be able to do it, but your cars cooling system will not run as efficiently with the fans not pulling air through the radiator.

 

I did a little more research because you were waiting for me to do it. Here is a some more neat read for you straight out of my 2003 Coupe Service Manual. Hopefully this will finally clear up how the G35 cooling fan system works. The table clearly shows engine speed and wheel speed inputs are provided for fan cooling control. The graph shows the correlation between vehicle speed, coolant temperature, refrigerant pressure and air conditioning switch in the on and off position. It is as clear as a glass of clean H2O to me. See next post for attachments.