05 Aviator Fan Roars

[DigitalAviator]

Hi all,

Anyone run into a problem with the cooling fan where it roars loudly under normal acceleration? The Aviator sounds like the roar of a heavily loaded semi accelerating...there's a ton of fan noise, but you dont have the thing floored and you're not really moving very fast.

So far, I've replaced the electric cooling fan relay (no change to the roar) and replaced the fan clutch. The roar used to happen 90% of the time regardless of engine temp, rpm or anything else. With a new fan clutch, the roar happens for about the first 60secs after i start the truck when the engine is cold and occasionally comes back if I'm stuck in traffic. The fan clutch I bought was a Four Seasons part from napa. Anyone think I should take that back and get a Motorcraft part? Any other ideas?

Thanks.

 

[DigitalAviator]

I read somewhere else on the web that someone improved this problem by replacing the thermostat but I dont see why that would change anything. The truck doesnt overheat now so this seems unnecessary.

If there is something in the clutch that needs to heat up for 60secs, i'm afraid that when winter comes that 60 sec warm up period will get much longer.

Having the a/c on or off doesnt seem to have any repeatable impact on the problem.

 

[silverfox103]

My fan on my 2003 operates identically. When I first start it in the morning, it runs at 2K rpm for just a few seconds. Then the rpm drops to the neighborhood of 825 rmp. It does roar, but only for a few seconds. I have seen posted for a similar problem, it could be your IAC valve, which needs to be replaced. Also I remember it mentioning, be sure to buy a genuine Ford IAC.

Tom

 

[DigitalAviator]

Ok, new wrinkle. I got a motorcraft fan clutch and installed that today. It keeps the fan engaged and roaring more often than the Four Seasons part so I guess i'll reinstall the Four Seasons clutch. Its amazing how quiet these engines can be when things are working right. Its also surprising much how much of a load a fully engaged fan puts on the engine. With the original clutch that had failed and was always engaged, I was only getting 13.5 mpg on the highway. With the Four Seasons part, i was getting 15mpg city, almost 22mpg highway.

I guess I'll live with the roar during the first minute or so after startup when everything is cold.

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[Slick Fan]

My '03 does the same thing when the engine is cold. It doesn't take long for it to quiet back down during summer months. Winter months will take longer, though.

That 2K startup RPM really bugs me though. I cringe every time, until the oil pressure hits. I'm halfway tempted to see if I can find someone to reconfigure my ECM to only make it rev to around 1,000 or 1,200 RPM at startup.