OWNED

Ok, I just noticed this... when I turn my car on (after sitting a night... or any time) the fan turns on (just starts spinning like it was at normal op temp...)

Anyways, I was thinking it could either be my fan clutch or a problem with one of the sensors...

before I go ripping things apart and replacing stuff I just wanna know, if it was a sensor... wouldnt that mean that the sensor inside the gauge cluster would read hot aswell?

A little info for you guys, my car runs good, but overheats when it sits still for awhile. (this sounds like fan clutch to me!!)

I hope its the fan clutch so I can just go get a nice E-fan and 'strap er on'.

Anyways, any help appreciated... any way to check?

Hollywood56

It could be the fan clutch,also change your t-stat with a mazda one if you don't have it on there.When my fan clutch went 138,000 it had the same symptoms.And while your doing that might as well flush the radiator.To check the fan clutch you can just most likely stop it with a wrench or a pencil.if it stop very easily that your problem.But make sure that the car is warmed up fully to do this test.

allforjesus06

on the neck from the water pump, near the top coolant cap, you'll see a 1 wire sensor, when your car is running wiggle that sucker slowly, and pull it out and put it back. that connection might be your problem.

OWNED

Ok, well i'll try that.

I did replace my T-stat and flushed the cooling system about 2 months ago (But I replaced the T-stat with one from Part-Source..?? Is that ok?)

And Hollywood56, while running at normal op temp I should stick a pencil in the fan... if it stops its a bad fan clutch.. and if it pulls my arm in and makes me a war-amp the fan clutch is good?

Thanks guys

SureShot

There is a part of the stat (brass disc) that extends below the stat valve.
It must cover a bypass port down in the pump housing or much of the hot coolant will bypass the radiator.

The fan clutch uses a silicon oil viscous fluid in two chambers inside.
The Bi-metal strip on the front bends outward as it warms and opens the valve from the reservoir side to the clutch side.
Centripetal force provides the pumping action to move the fluid.
When it sits for a few hours, it will spin the fan briefly on startup, then freewheel.
After 100,000 miles the bearing seals inside wear, and the bearing lube starts to weaken the clutch fluid's grip.
Both the S4 & S5 clutch freewheel when cold.
The s4 clutch increases it's bite gradually with temperature rise.
The s5 clutch is more on-off. (It just coasts until is gets warm)
Once they are warm, the fan speed goes up with engine speed to about 4000 RPM.
As the engine revs higher the fan stays at ~4K.
If your warmed up fan only revs up to ~2500 RPM, it's bad.