S1 Radiator Fan

[philthy]

What temperature does the S1 fan usually kick in at? Mine has been coming on at 90-95c and making a hell of a noise when it does (bearings starting to go I think)

JJ said soemthing about one of them temp senders being gubbed, doubt its the stack one as it sits at 82-84c on motorway driving

[steve_weegie]

That would seem about right phil - my s2 fan comes on at bang on 100 so you're in the right ball park.

What makes JJ think the sensor is gubbed??

Cheers,

Steve

[jj]

The fan kept coming on whilst driving about town.

Given that its about 3 degrees outside and the stack said 90-91 when the fan was going on and off, I didnt think that was normal, as mine never did that....?

I remembered reading something about whatever sender it is that turns the fan on and off being dodgy?

[Sanjøy]

I think it was 90+ when it came on, I ended up changing the brown or blue sender too. Then the fan died a few months later.

[Stewart]

I think mine is 95 or perhaps higher, it's a rare experience so I couldn't say with too much certainty.

[BiggestNizzy]

95 is about right,

[robin]

On S1 elise the fan comes on when the ECU thinks the engine is up near 100C. The actual indicated temperature will vary as the dash is driven by the other sensor, which has a common ground via the engine block and chassis and so is sensitive to voltage offsets caused by current flowing through that ground path, not to mention there is no calibration of the dash relative to the sensor, so you will probably get +/- 5% error over the complete operating range, I would estimate.

In this weather I would not expect the fan on an S1 to come on all that often while the engine is just idling. Certainly on some of them, the fan just won't come on at all in these conditions.

If your's used not to come on in traffic and now does, then something has changed. It could be the ECU sensor (though I think that is not all that likely), or an airlock in the radiator (due to a leak or worse).

From cold when you start the engine and just leave it idling, the temperature should rise steadily to somewhere around the 80-90C mark and then level out - this is the 'stat opening temperature. It should stay level at that temperature for quite a while. Meanwhile, the radiator should start to get hot from the driver's side and the heat will then spread to the pax side. The temp of the rad will rise steadily towards the fan operating temperature, at which point the fan will kick in (subject to the proviso above - on many S1's it just doesn't generate enough heat to reach that point).

If you get one of those pointy IR thermometer thingmies you should be able to measure the temperature at both sides of the radiator during this process and see what happens.

S2's have poor flow through the radiator on idle at the best of times, so the fan tends to rise much more quickly and the fan is required more often to bring the temp back down.

Cheers,
Robin