Fans on all the time? (sorry if this is old..)

[greenmachine]

Hi, just got myself a lovely 1996 Mk2 NA.

Should the two engine bay fans be running all the time the engine is?

(sorry if this has been asked alot, i did search)

thanks

[jasongtr]

2 engine bay fans?

[greenmachine]

That'll be one fan then

[jasongtr]

never seen one with 2x engine bay fans thats why i commented, usually theres just one in the drivers side intake vent in front of the rear drivers side wheel.

wheres the other one?

or do you mean the fans in the engine lid - ie a more common turbo modification

[greenmachine]

I just assumed there was one both sides.

Just one.

So is this normal?

[alanmr2turbo]

you will only have 1 in the engine bay on the drivers side

[greenmachine]

So should it run all the time the engine is?
Temp gauge is fine.

[alanmr2turbo]

no

There is or should be a sensor on the engine lid. If this is missing or broken then they will be on all the time.

[jasongtr]

the other side will be open to feed the airbox,

anyway my understanding is the temp probe on the underside of the engine lid controls the engine bay fan, so shouldnt be on all the time

[greenmachine]

Yes i can see the probe on the lid, but as far as i can tell the wire just runs to an earth behind the airbox.

Can i rule out the Thermostat sensor for this problem?
Will it be something to so with the Lid sensor?

[jasongtr]

nothing to do with the thermostat in the cooling system, theres more than one wire off the sensor, theres also a fan controller box behind the carpet in the boot next to the ecu, that controls the engine bay fan

[greenmachine]

Does the fact it runs only when the engine starts, shed any light on it?

[Marlowe]

Does it run the moment you turn ignition to 'on' (ie before you start engine up)? If so sounds like the problem I had - the previous owner had fitted a NA temp switch instead of a Turbo temp sensor. You could have the same issue (with it being a NA could be the wrong temp switch or a Turbo temp sensor fitted, or simply that the switch has failed?)

If it is the same symptom have a look at your temp switch as a starting point.

[greenmachine]

no, like i say its only when the engine is running.
I can have the ignition on, but the fan wont start.

[vishpish]

mine runs all the time when the keys turned (even if engine is off)

[greenmachine]

Thats interesting.
The guy i got it off is an MR2 enthusiast and swears its ok to be on all the time..
Any definitive answer here..?

[mrfil13]

The fan should come in if the engine bay is about 85 degrees at the sensor on the lid or if the wire to the sensor is disconnected or broken. No issue with it been on all the time. Normally it would only come on when sat in traffic.

[alan wheeldon]

Thats interesting.
The guy i got it off is an MR2 enthusiast and swears its ok to be on all the time..
Any definitive answer here..?

This is fine, my car is set up for the fan to be on constantly when the ignition is on. Personal preference but i believe it keeps things running a little better.

Dont worry about it and start enjoying it