Radiator Fan

[TTT]

Just a few questions.

The Fan that runs off the water pump - what makes it engage and/or release?

when you first start the car it is engaged and releases as soon as you start moving.

then seems to come on once up to operating temps and release again as you get moving.

Occasionally mine will stay engaged for a lot longer.

I've had it engaged even when over 4500rpm in 1st at some stage.

so....

is my car running hot?

is the fan assembly faulty?

is my water pump faulty?

I'll be getting a ECUDATASCAN device soon enough to see the actual temp but at the moment, the factory gauge sits at half way as usual.

[blind_elk]

From the Davies Craig website (http://www.daviescraig.com.au/Fan_Clutches-b-content.aspx)

A thermal clutch fan operates using silicon fluid as a viscous coupling medium. When the clutch is cool and disengaged, most of the silicon fluid is stored in the reservoir allowing your fan clutch to slip relative to your water pump shaft thereby spinning at a lower RPM than the water pump. This saves you money because the horsepower from your engine is not wasted driving a clutch fan when it's not needed. As your engine heats up, the thermal spring on the front of the clutch expands, which opens a valve allowing the silicon fluid to drive your clutch at an increased RPM. This provides more air flow through your radiator, preventing your car from overheating.