2008 Jeep Hydraulic Fan Always Running?

  • Thread starter Thread starter whip
  • Start date Start date
W

whip

Guest
I have a 2008 Jeep Grand Cherokee 5.7L with a Hydraulic Cooling Fan, ie. fan is driven by the Power steering Pump. Problem is that It is running at high Speed all the time except at Idle. I understand that the fan has a minimum Fluid flow which will turn the fan at 100-500 RPM, But my fan anywhere off idle is running at thousands of rpm, very loud. It doesn't matter if the engine is cold, AC off, even cruising at highway speeds in Cool weather. Not towing anything? Don't understand, any ideas appreciated.
 
We've seen this happen in the past. The silicone fluid coupler isn't functioning properly. Most likely there is a mechanical bind in the free wheeling bearing inside the fluid coupler. This is definitely a warranty issue. They can not be serviced. In most cases the blades can be removed from your present fan onto a fresh de-clutching fan hub assembly.

I sympathise with you as these fans have several deep pitched blades and if the hub is locked up 1:1 with no slippage the air roar racket is defining!

Your assesmant of how thes fans are supposed to work is pretty close. Actually the fan blades draws air of varing temperatures through the radiator. The hotter the air the fluid inside the fan hub provides less slippage to the blades. Thus it will pull more air. Take into consideration the movement of the car. The faster the speed of the car more air is forced through the radiator. This amazing fan hub when working properly constantly "feels" the temperature of the air as it passes by the finned aluminum hub assembly.
 
Back
Top