Aux Fan Always on

Discussion in 'Technical' started by Pepper, Nov 7, 2011.

  1. Pepper

    Pepper 1991 N/A Slicktop

    I have an aftermarket rad on my
    NA and the aux fan is always on, CTS has been replaced, no error codes.
    Running under 80C

    Im assuming it has to do with the wiring.
    Whats the added fuel consumption on running the fan 24/7?

    Should i be concerned? Or should i just not try fixing
    Something thats not broken? :p
  2. rollin

    rollin First 9

    the relay could be faulty
  3. OZX_320

    OZX_320 Detachable Member

    the aux fan in front of the ac radiator, or a thermo fitted to your aftermarket radiator?
    How is it controlled? via ecu signal, thermo switch or hob switch? or directly from the ignition?
  4. Pepper

    Pepper 1991 N/A Slicktop

    Between rad and engine.
    Big mofo.

    Unsure of wiring, thats the issue.
    Im wondering if the added stress on alternator and slightky extra fuel consumption vs better cooling.

    Is it really worth the hassle of fixing
  5. dinh300zx

    dinh300zx ZLOVER

    I use thermo fan for my TT , too . I use relay and adjustable thermo switch to control the fan . It will start at 85 degree and off at 80 degree . If your fan start instantly when you turn the ignition on , then likely it get power from ignition . Even if it use relay , and fan start after you turn on the engine , then the relay signal wire still come from ignition . Further more , if fan use relay and thermo switch , then thermo switch activated too early , trigger the fan run and possibly never stop .
    Running the engine too cool is not really good . As the operating temp is around 83 to around 90 degree . And the thermo fan will suck around 12 amp , so not really good if you have too many accessory .
  6. Pepper

    Pepper 1991 N/A Slicktop

    Its the clutch fan.

    My bad.

    Let me get my facts straight and ill re-post later.
  7. Sanouske

    Sanouske Retired Moderator

    White fan attached to the viscous clutch bolted to the engine? That (should be) a black shroud covers intirely? Are you talking about that?

    If so in an ideal world when the engine is cold, the viscous clutch will allow the fan to free spin up until the clutch plates warm enough to grip the fan into full swing. This is meant to allow the engine to come up to temperature but also allow for less engine strain upon start up.

    When these viscous clutches wear or fail the fan will be locked and will be powered up into full swing on first engine start. This can decrease the engines efficiency for warming up to operating temp slightly. But isn't a be all end all factor. Yet should be replaced or repaired.

    Failing all that and it's not the engine fan. You've been smoking far too much hooch and need to work out what your on about. Than let us know. Lol.

  8. a2zed

    a2zed Guest

    No, completely wrong man.

    The viscous hub is a fluid coupling, there are no internal parts to wear other than a seal and bearing. A correctly operating viscous hub will allow the fan to spin at less than engine RPM as the bi-metallic strip that senses airflow across the front of the hub has closed a small valve internally that limits fluid flow.

    Once the engine is up to temp, the bi-metallic strip allows the valve to open giving greater oil flow, this causes drag in the internal vanes making the fan spin at a higher rpm. Most viscous fans are limited to 3000ish rpm to prevent cavitation and excess fan noise, fuel consumption and vibration.

    All viscous fans will give a bit of noise for the first 10 seconds or so on start as the fluid has had a chance to settle in the hub. after a few spins, the fluid and coupling are now working as they should.

    Pepper, does your car have a viscous fan or an electric?
    Last edited by a moderator: Nov 10, 2011
  9. Sanouske

    Sanouske Retired Moderator

    Man ive been working with ****ing tractor parts for far too long. Keep mixing up my absorbed information, between them and automotive. Bad run of late. =(

    I need a holiday. And a new job. **** it.

Share This Page