NC Cooling Fan

jackdog · Postby **jackdog** » Thu Jun 19, 2014 6:39 pm

The cooling fan on my 08NC stays on after I switch off the engine. Is this meant to be the case and if so how long should it stay on? If I switch the ignition on and off the fan stops. Is this normal and if not what should I look at first?

JBT · Postby **JBT** » Thu Jun 19, 2014 8:44 pm

It has never happened on mine. I have no idea where you would start to find out why it does this. Is the car modified? Aftermarket PCM?

jackdog · Postby **jackdog** » Thu Jun 19, 2014 8:59 pm

The car is standard, I was thinking it might be a faulty relay.

JBT · Postby **JBT** » Thu Jun 19, 2014 9:18 pm

Could be...but which one? You'd need to trace wires or get hold of a wiring diagram to find it. Auto electrician or Mazda dealer?

Dan · Postby **Dan** » Thu Jun 19, 2014 11:00 pm

Does it turn off eventually if you don't switch the ignition on/off?

Many cars have a feature to leave the cooling fan on if the thermostat reads a certain temperature (my Evo's fan stays on quite often due to heat). If the NC has this feature then it could also be something like the Thermostat Sensor.

Regie · Postby **Regie** » Fri Jun 20, 2014 2:32 pm

Yep my fans stay on after the car has been switched off. It's normal.

It only did it on a stinking hot track day

Charlie Brown · Postby **Charlie Brown** » Fri Jun 20, 2014 4:23 pm

As Regie says, fan stays on when the engine is turned off and the operating temperature is higher than normal.

As the weather isn’t hot at the moment, I’d check your fluid levels.

Also check the header tank as they get brittle with age and crack around the neck.

jackdog · Postby **jackdog** » Sun Jun 22, 2014 8:20 pm

Thanks everyone, at least I know the fan is working properly. The coolant level was ok, I think I'll get the cooling system pressure tested.

jackdog · Postby **jackdog** » Wed Jun 25, 2014 9:33 pm

Hi Everyone

I was just wondering how far the temperature needle should move and where it should sit on a stock car. Mine is presently getting to a bar over half way and then dropping back to half or just under half way. I've never noticed it really move previously but I've just glanced at it, not watched it. Is this normal? There's sufficient fluid, no obvious leaks and the oil is clean with no obvious water in it.

If this isn't normal does anyone have an idea as to the likely culprit.

Thanks

Regie · Postby **Regie** » Wed Jun 25, 2014 10:38 pm

i have my dash dyno attached all the time so monitor temps through that

mine goes anywhere from 75 to 105* the fans kick in when it hits 100* (heavy traffic hot day)

I haven't noticed my gauge moving much, its sits at the halfway point all the time

What year NC and how many Kms have you got?

jackdog · Postby **jackdog** » Wed Jun 25, 2014 10:43 pm

Sounds like I have a problem! I'm guessing its a thermostat. It's an 08 roadster manual with 30,000km.

JBT · Postby **JBT** » Thu Jun 26, 2014 10:25 am

jackdog wrote:If this isn't normal does anyone have an idea as to the likely culprit.

It is not normal.
My gauge has never moved off normal (once warmed up) including at track days in Brisbane's summer heat. My car is 6 years old with 85,000km.
I have also never heard the fans operate after shutdown.
The standard temp gauge has a "dead zone" for the normal temperature range - see Regie's post above. If the gauge indicates high then you have a problem.
It may be a thermostat issue or one of your fans may be crook or something else.... I think Charlie Brown had a thermostat go bad - search in the technical guides area.
I believe the fan relays (three of them?) are in the relay and fuse box.

Mr Morlock · Postby **Mr Morlock** » Thu Jun 26, 2014 11:40 am

endorse JBT's comment. Nothng wrong with getting it checked by the radiator people or a mechanic.

jackdog · Postby **jackdog** » Thu Jun 26, 2014 1:50 pm

Thanks again, booked it in for a checkup!

Charlie Brown · Postby **Charlie Brown** » Thu Jun 26, 2014 1:56 pm

My thermostat went at 120K and was stuck in the full open position, so the temperature would drop to the bottom mark once you drove the car and rise towards normal when stopped.

I'm surprised that your fans don't stay on after a track session JBT. Mine are always on for a few minutes after a session. Seems pretty typical condition for NC's when I walk around the pits at Wakefield. Must be the lower humidity down here.

jackdog, I'm not sure that you have a problem. My temperature gauge will wander left and right of the vertical position, say 11:30 to 12:30.