Fan staying on on my Cooper S

[Purple S]

Hey folks,

Apologies in advance if this seems like a dumb question...

I've an r53 Cooper S. I had to have a new (reconditioned) engine put in last May and it's been going fine except when I'm in slow moving traffic or if I'm sitting in idle the fan will come on, and stay on even after I've gotten out of the car and locked it. I did get a friend of a friend who is a mechanic to look at it and he said he'd need it for longer to do a full diagnostic but the basics was fine and nothing is over heating and it was more than likely just a censor that was knocking the fan on without due cause. So, I kind of ignored it after that as I just have been mental busy but I've been wondering if putting this on the long finger could be detremental to the car...also does anyone know if this is a big job to fix - in which case I'll probably have to wait till after Crimbo!

Thanks

[gonzales]

I have the same problem with my R53 if I have been sat in traffic for a long time. i have been re-assured by my garage that everything is fine and it is just a sensor that has got out of whack. I have found though then when it happens if you start the car again and then turn it straight back off that the sensor/fan re-sets itself and turns off fine. I think it is just the long time idling that it dislikes (almost as much as I do)

[Eviltad]

Mine does it too. Just check your coolant is OK and half an eye on temp gauge.

[Chr1sch]

TotAlly normal, the top mount intercooler just soaks up heat when stationary and just helps the engine get hotter and hotter, as already said, coolant and oil levels are key, otherwise she'll be fine

If you are planning any mods a GRS intercooler is a great start and way more efficient...

[AARONM3]

Probably not relevant as you've got a recon engine but if you haven't replaced the thermostat it's worth a look. Mine would turn the fan on even after a short while from cold but since replacing the thermostat with its perished gasket it seems a lot happier- although my problem was highlighted by increased water consumption and dropping water after short journeys (before the engine got really hot and presumably then the gasket made a tight enough seal).

[DanGT]

It is normal if the engine is hot for the fan to run on after the car is switched off. the qestion is if the fan is coming on to early or the car is getting to hot. If the water level is ok. Check the heater is working ok. If the engine is not getting to hot and the fan is a bit over active it is just the temp sensor for the fan. I think the is a diffrent sensor that the one that reads to the instruments.