What temp should cooling fan come on? S2 K series

[colintinto]

Hi All,

Starting to think I have an issue with my cooling fan. Not sure I've ever heard it, and Friday ended up sitting in traffic for quite a while, and the temperature kept on rising, getting to 103 before I moved off again, and I still hadn't heard the fan.

Firstly, I assume I'd be able to hear the fan, and secondly, what temp does it usually kick in at?

In normal stop start traffic it seems to settle about 95, but living in Stirling, we don't do traffic jams

Colin

[Kev]

I'm sure mine kicks in at 102. Try spinning the fan, they have a habit of seizing

[andyc]

102 for me

[j2 lot]

Sure mine used to be 102 as well.

[whaleys]

Mine kicks in at 103, I think the range is 102-105 that some will kick in. However I'll be corrected if I am wrong, but if you go over 105 that's moving into territory that is not good for the engine.

TBH if its not kicking in at 103 then I would be doing some checks just to make sure that the fan is good. As Kev said I would try moving the fan blades, the should move quite easily with only slight resistance.

[simon]

the range is 102-105

This. The fan on my 111S always came on a short time after it hit 103. I occasionally saw 104 before the fan brought the temp down, usually in the pits at Knockhill!

[gorrie]

Worth checking it out though, in case it's a seized fan... but keep a VERY close eye on it when you do. I noticed the same thing with mine after doing the fast idle test at the MOT station. Came home to test it out so left it idling in the garage for a while.... stuck the kettle on & arrived back in the garage just in time to witness a geysir errupt.
Quickly turned the engine off and it had hit 110C... fan was seized... lol.

[campbell]

A broken wire stopped my S1 fan working. It was routed under the fusebox which wasn't going to help longevity...probably different setup altogether for S2 of course.

There is presumably a way to hotwire the fan to test it?

For ref, my fan kicks on at 102-104 from memory...and goes off again at about 95 or 96.

All the sensors will give slightly different readings of course - remember you're looking at a digital display...we'd never notice this with swept analogue dials

[robin]

The correlation between fan turn on point and indicated dash temperature is much closer on S2 than S1 - on the S1 there are two sensors, one for the dash, one for the ECU (and thus the fan), and so there can be a fairly large difference between the temperatures the two sensors read due to variations in the actual sensors. With the S2 there is one sensor that feeds the ECU; the ECU then feeds the dash with a PWM signal which is reasonably accurate - I would expect 1% tolerance, max (i.e. 1 degree of variation). On my 135R the turn on temp is 98, but I do believe that for the VVC the turn on point is higher (102-ish).

Cheers,
Robin

[KingK_series]

The correlation between fan turn on point and indicated dash temperature is much closer on S2 than S1 - on the S1 there are two sensors, one for the dash, one for the ECU (and thus the fan), and so there can be a fairly large difference between the temperatures the two sensors read due to variations in the actual sensors. With the S2 there is one sensor that feeds the ECU; the ECU then feeds the dash with a PWM signal which is reasonably accurate - I would expect 1% tolerance, max (i.e. 1 degree of variation). On my 135R the turn on temp is 98, but I do believe that for the VVC the turn on point is higher (102-ish).

Cheers,
Robin

That I agree on totally, however having calibrated my Omex ecu to the black sensors on my S2 I discovered 2 things;-

1/ the sensors themselves are all remarkably consistant, 22 were tested
2/ but the pmw signal gives a inaccurate by as much as 5/6 deg to the dash - it doesn't matter because the ecu once calibrated has the correct temp, but the stack value will be off.