As the title asks why? What I learnt from working on old small block and big block engines is that they score zero points against an Electric-fan. It is outdated technology and with all the fancy electronics a GMC sierra comes with, why not an E-fan?

Clutch fans above all rob power from your engine (8-20hp) on a small block engines. They suck more fuel, are much much less reliable, are dangerous for your engine and yourself, and are less effective.

Honestly, before I got my 2002 sierra, I thought that clutch fans had died away in the 80's. So I was pretty surprised when I saw my truck with one.

For example mine, I can tell mine needs replacement as I've recently been hearing it when the engine isn't even hot. Like when I first start it, during cold wet days, the clutch seems to engage for no aparent reason.

So, can anyone tell me why GM still uses these things?

 

Very reliable and move a ton of air.

 

+1 and inexpensive and easy to produce. There's enough room to fit the clutch fan (efans have often been used due to space constraints), the vehicle is rear wheel drive with the engine facing forward so a clutch fan will bolt right on easily (you'll notice that front wheel drive vehicles with transverse mounted engines all have efans as there's no way for the engine to drive any sort of fan). The e-fans came about on the trucks as a way to improve fuel economy I believe, but they work out great for those of us interested in performance.

 

Really? I have to disagree with reliability. I've seen countless clutch fans with seized clutches making the fan turn constantly non-stop.

But do they really move more air? Suppose you compare it to a dual electric fan?

Reason I'm asking is because the fact that it runs when not needed is a sign of break-down and should be replacing it soon. I'm 99% sure i'll go electric but don't want to make a bad decision.

The fact that you say it moves more air questions my thinking though. Maybe to someone who owns a muscle or sports car, moving more air isn't so important because by the time the engine is working hard enough to need the fan running, the speed will be elevated enough to bring in tons of air.

But on trucks, such as mine, I tend to use the engine a lot for towing and off-road, making the engine work hard at low speeds, therefore not raking in much air. So obviously a truck needs a more airflow-capable fan than a muscle car.

So, you guys tell me, if I'm using my tuck mostly for off-road use and towing, not higher speeds, is it a wise decision to switch to an E-fan?

 

So it works normally then when it breaks it is always on? That sound pretty reliable to me since there will always be airflow regardless if the clutch works or not. With Efans, motors can fail, alternator can fail, batteries can fail, wires can corrode....see my point? There is a higher potential for failure with efans.

Fans are pointless above 40mph since as you point out when you get up to speed, there is plenty of air coming in through the grill anyway. This is where efans are more efficient and they can be turned off above a certain speed.

In your case I would do Efans since they are more controllable than a clutch fan. Also, if you ever ford water its a good idea to turn the fans off since if you run into water and the fan is spinning quickly you can potentially destroy the blades from the sudden impact.

Clutch fans have their place. They are cheap, reliable, capable, and simple, therefor they suffice very well for the majority of people.

 

Don't clutch fans just freewheel above a certain speed so they're not really dragging on the engine?

 

I don't like them strictly for the power robbing application of it.

 

I had a 96 tahoe and that fan clutch went bad,it was constantly engaged and you should have heard it at 4000+RPM LOL,it was Loud but damn it was pullin some air.

 

One big plus I like about e-fans compared to a clutch fan is if your engine is overheating, you can turn your engine off and still have the fan running. I like the additional control you have over your engines cooling as well. Setup fan speed, turn on/off at will. cleaner, usually provides more room.

And overall, it won't start damaging the bearings on your water pump over time if there's a slight imbalance.

I just hope that when I'm spinning my engine at 4500RPM in deep mud and snow, an e-fan it will provide as adequate airflow for my engine.

 

Dont't get me wrong, I prefer efans, I have them myself, but the factory clutch fan is a time proven piece. I agree, I like how I can turn my efans on with the engine off...only thing is that you're cooling the coolant sitting in the radiator which isn't circulating through the engine