Radiator fan runs when engine is cold

[mlupone]

I have a 2004 Suburban Z71 with 205K miles.

QUESTION: Should the radiator fan run at initial start-up when the engine is cold?

I have never noticed whether it runs or not when you start the engine from a cold start. Yesterday, I noticed that the dashboard temperature gauge wasn't operating; e.g. the needle was sitting at/just below 160 degrees after driving for 30 min or so. I thought the engine coolant temp sensor was bad, but this morning the dash temp gauge was reading properly. I also noticed that the fan was running from a cold start. Since the fan is connected to the water pump pulley and the water pump is continuously running when the engine is operating, shouldn't I expect the fan to run continuously as well?

As an aside, the cooling system has always been properly maintained and the water pump was replaced at 150K miles.

Matt

 

[B-train]

Your truck has a viscous fan coupler. They will run when cold and should taper off after a few minutes. Then kick on when the temp rises to the point of needed airflow for cooling

 

[mlupone]

Your truck has a viscous fan coupler. They will run when cold and should taper off after a few minutes. Then kick on when the temp rises to the point of needed airflow for cooling

Thanks B-train!

 

[mattbta]

If you replace the fan clutch, go OEM. There have been numerous reports of cheaper aftermarket clutches causing the truck to sound like a freight-liner after startup. I went OEM and it was still quite noticeable. Or do an e-fan conversion.

 

[Sam Harris]

If you replace the fan clutch, go OEM. There have been numerous reports of cheaper aftermarket clutches causing the truck to sound like a freight-liner after startup. I went OEM and it was still quite noticeable. Or do an e-fan conversion.

Efan conversion 100%.. and since you’ll need a tuner to enable the fans.. I mean, you have to do a tune as well.. it’s a cheap, easy, and definitely worthwhile upgrade. And it will also give you a lot more room up front for something to assist with eh.. proper air induction..

 

[mlupone]

Thanks for the e-fan recommendation. Seriously thinking about going this route. Why would an e-fan need a "tune".

I found this on YouTube. Seems somewhat complex.

 

[Fless]

The fan will be (should be) loose on the clutch when the engine is cold, but there is always a little engagement and centrifugal force that makes the blades move. As the clutch heats up the connection to the fan tightens and it forces it to run at speed.

When the engine is cold (and off) you should be able to easily turn the fan blades. After a warm shut-down, the fan blades should be tight to the clutch and hard to move by hand.

 

[mlupone]

Here's an opinion against; e.g. e-fans are huge power hog, need bigger alternator/fuses... (per this YouTube video).

 

[Fless]

I've towed several different 4K lb campers in the Rocky Mountains (Denver to Western Slope, multiple high passes) for several years now and haven't needed the conversion to keep the engine cool. If the rest of your cooling system is good, the non-efan should work fine.

 

[Marky Dissod]

Thanks for the e-fan recommendation. Seriously thinking about going this route. Why would an e-fan need a "tune"?

If the vehicle's original fan is mechanical, then that pcm is so written - it will not bother trying to control it.
If the vehicle's original fanS are electrical, that pcm is written to control electrical fans in response to either coolant temp or AC psi.

If your pcm is 'unaware' of an electrical fans conversion, then your electrical fans will be inert -
UNLESS your electrical fans are NOT controlled by the pcm (older style conversion?)

Here's an opinion against; e.g. e-fans are huge power hog, need bigger alternator/fuses... (per this YouTube video).

1ROAD's truck is a GMT431.
Did ANY GMT400s have electric fans, or OE electrical wiring commensurate with electric fans?

Put another way: how well does this apply to GMT800s?
How many e-fan conversions had the same problems as 1ROAD with his aftermarket dual electric fan conversion?