Thanks so much mate. I will check the coolant tempt next time I'm driving the car. Sadly the fan doesn't work on low speed, so it's going to need attention.
Is it DIY or best to get someone who knows the cars to do it?
Get it tested properly first, ideally by a Rover friendly garage with a T4 or some decent diagnostic kit. It is probably worn brushes in the fan but sometimes it can be a sender unit fault that tells the fan when to come on.
i.e. My 75 is odd because the demist test works 'But' the fan does not kick in when it should i.e. at 100oC. Your Rover does not always need the fan so this is fine for normal driving but if I do ever hit traffic and using the on board digital temp gauge I stick the fan on if it goes past 96oc, How do I do that?? Basically by triggering the air con on 'LO' and with 'econ' off triggers the fan to spin, hey presto, temp soon comes back down again in no time.
Not ideal I know, but fan replacement with all the gubbins is a front bumper off job.
Don't worry, I have a list of jobs to get done on mine somewhere and it looks like a new loo roll, the fan replacement is on there somewhere near the top!!