It seems to be related to engine and/or ambient temperature, because I haven't really noticed until things have gotten more chilly!
Noise 1: There's a squeaking at startup/when the engine is cold. Maybe squeaking is a bit harsh, much more like a chirping sound. I'm guessing it's the alternator belt as it squeaks when turning the Air Con on and when the revs dip a little.
Noise 2: Slightly more worrying is this noise from the engine again, on startup and noticeable when I reverse out of my driveway. It's hard to describe but it sounds like the sort of metallic rattling like the exhaust is loose/vibrating. If it was this though, it would presumably do this all the time, but once the engine is warming up, it no longer does this. Turning the steering wheel to full lock seems to also bring this vibrating noise as well.
Noise 3: Even more worrying is a whining noise from the engine, Again, it's when the engine is cold and seems to be loudest at around 1800RPM. It sounds a bit like this one, but not as severe and it disappears/gets drowned out when the revs climb above 2500. https://www.youtube.com/watch?v=e9pk1gLQNtM
I don't know if all of these sounds are related. I tried getting my ear down and finding a location under the bonnet but there doesn't seem to be a particular area where it's coming from.
On a potentially similarly related note does anyone recommend an interval for getting the cambelt/waterpump replaced? It's done just shy of 82000 miles on a 56 reg, but I don't seem to have a bill for when it was last done from a previous owner.
As far as I can work out apart from the noises everything else is running pretty well, a little down on power when cold but once up to temperature all is well!