COU fan (I believe) Is randomly spinning faster than it should

this is rather normal. when your cpu is idle it's using less power and requires the fan to spin at lower rpm's to keep it at decent temperature. when its loading a video/game the cpu has more to do and will consume more power thus making it hotter and requiring the cpu fan to spin faster to keep the cpu cool. same applies to a gpu.

bump

Well the thing is that it shouldn't be speeding up like that on non stressful situations, its not just when it starts up a game, it revs all throughout it, it also does the same whenever i put it to sleep, it'll simmer down then BOOM, speed up again and then calm down after a bit.

If the contact between HSF and CPU is weak, the CPU may be heating up more easily/quickly than it normally should and cause the fan speed to spike under short CPU load bursts.

SO how can or should i diagnose or fix the problem? Should I tighten the screws securing the fan to the CPU or what? (I'm also working on a very tight budget here if it requires a replacement or professional repair)

Well I would check the temperatures and perhaps post them here for people to take a look at (at idle and when busy) usually the motherboard comes with utilities for this. If you go into the BIOS at boot there is usually a monitoring page in there for cpu and voltages.

The 8150 can get quite toasty under load and takes some decent cooling. I recently built one of these for my friend and whilst it doesn't concern him I find the stock cooler unbearable. It doesn't help with him insisting on running boinc so every chance it gets it does the helicopter thing. Even under normal loads the fan varies quite a bit and you really hear the ramping up and down. These cpus have fairly aggressive power saving features so they do vary from minute to minute it seems. You can switch some things in the BIOS I guess and set your own ranges, but to be honest I'm not so comfortable doing that on a beefy cpu.

At the end of the day, the supplied cooler is a noisy bugger (and doesn't cool that well under heavy load either) so I'll be swapping my mates out as soon as he's settled into his new flat.

I shall be changing it over to the Hyper 212 Evo, seems a popular choice, effective, reasonably cheap and doesn't look too painful to fit (as my mate's case has access to the back of the motherboard). Would be nice if someone released a decent cooler that isn't huge and just used the standard AMD fitting instead of back plates!

Do post your temps up if you can though, it will give people a clue if there is a maybe a mounting problem. Don't worry too much in the meantime, I doubt very much that there is anything that warrants professional repairs!

Its all science, you need the large surface area to disperse that heat, hence the heatsink is large (the 212 EVO isnt even the largest on the market by any stretch, look at the Noctua NH-D14). And that much metal needs something better than clips to hold in place.

You fan will spin faster and slower depending on the load the CPU is under, that's to be expected. As for the loud noise, stock heat sinks are never that great (Intel ones are even worse). If it seems excessively loud, check if there are any wires in the fans path, that can cause a lot of noise. But otherwise follow Womble's suggestions.

Hmm...just realised that it is an HP system so may not be the standard AMD cooler and case room...my bad 

Still post some temps though if you can, not going to hurt and maybe some more suggestions to come though.