Hi everyone, I'm new here and this is my first post so be gentle ,I'm not getin much help elsewhere so maybe it's a uk thing,. I just bought a new car 2 weeks ago (2008 325i m-sport) car has been great and I love everything about it, however I have noticed a strange humming type motor-ish noise coming from the car when idle and revs at 1000rpm, it wasn't much of an issue when I first noticed as there are a few strange (electrical) noises come from these cars (so I've heard), but now I've realised how to get the noise on I realise it isn't right and it's also got worse. I am pulling my hair out over it as I've been to 3 garages to check what it is and all said they can't put a finger on it as noise wouldn't come on all the time (typical) bmw also said it would need to be on constant for them to look at it, the reason I am stressing out over it is that although car has warranty it's still under guarantee from the garage I got it from (but 200 miles away) so would like to get a answer so if any issues I can speak to garage. Basically, it doesn't do the noise first thing when started (cold) but gradually builds up as car heats up. Then when at running temp that is the worst and comes and goes, it sounds like some fan or pump on its way out, I will add a video and would be hugely gratefull if anyone can help. Or even say they recognise the noise, thankyou everyone who takes time to help. (Everytime noise appears I am revving engine at 1000rpm)