Well, that grate leads to the hard drive. Air comes in through that grill, past the hard drive, into the heat sink, through the fan and out the hinge grill. If the grating noise is coming out of the hinge grill also, it is most likely that you need a replacement fan. If it is just coming from the front portside grill, then it would appear to be a hard drive problem. Generally however, hard drive problems cause the the computer to stop functioning. Can you still boot up your system, read files e.t.c?

[quote|QEIIRepair]Well, that grate leads to the hard drive. Air comes in through that grill, past the hard drive, into the heat sink, through the fan and out the hinge grill. If the grating noise is coming out of the hinge grill also, it is most likely that you need a replacement fan. If it is just coming from the front portside grill, then it would appear to be a hard drive problem. Generally however, hard drive problems cause the the computer to stop functioning. Can you still boot up your system, read files e.t.c?[/quote]

Hi there, thanks for your reply - no the system wont boot up at all if the noise begins as soon as you start the machine up. If the machine is already running and the noise starts then it freezes. The thing is it is quite loud, a bit like something catching on a desktop fan, and along with the grating sound there's a kind of screeching. To me it reminds me of a bearing failing on a wheel. If you place your hand under the front port side of the machine while its making this noise, you can actually feel the vibration of whatever it is that is spinning and catching. Its as though something is spinning very fast, but is out of balance.

Thanks for letting me know thats where the hard drive is located. I suppose thats one of the most expensive parts to replace??? Id be very gratfeul to hear any other thoughts you might have on this.

Regards

Shaun

[quote|Nuch]Hi there, thanks for your reply - no the system wont boot up at all if the noise begins as soon as you start the machine up. If the machine is already running and the noise starts then it freezes. The thing is it is quite loud, a bit like something catching on a desktop fan, and along with the grating sound there's a kind of screeching. To me it reminds me of a bearing failing on a wheel. If you place your hand under the front port side of the machine while its making this noise, you can actually feel the vibration of whatever it is that is spinning and catching. Its as though something is spinning very fast, but is out of balance. Thanks for letting me know thats where the hard drive is located. I suppose thats one of the most expensive parts to replace??? Id be very gratfeul to hear any other thoughts you might have on this. Regards Shaun[/quote]

Most likely that is a bad hard drive. They are not overly expensive, but they are a bit of a pain to replace. If you can follow the guides on this site you should be fine, but if that looks a bit beyond what you are comfortable with, you might want to take it to a tech.

[quote|Sarabian]Most likely that is a bad hard drive. They are not overly expensive, but they are a bit of a pain to replace. If you can follow the guides on this site you should be fine, but if that looks a bit beyond what you are comfortable with, you might want to take it to a tech.[/quote]

Many thanks to both of you for your help. At least it helped me diagnose the problem. I looked at the guide, and I reckon I could do it, but whilst hunting for answers I came across a local Mac repair guy that can replace it for £30 labour charge. Having spoken to him on the phone Im confident enough that he can do the job, so Im going to let him tackle it. Thanks once again.

Rgrds

Shaun

[quote|Nuch]Many thanks to both of you for your help. At least it helped me diagnose the problem. I looked at the guide, and I reckon I could do it, but whilst hunting for answers I came across a local Mac repair guy that can replace it for £30 labour charge. Having spoken to him on the phone Im confident enough that he can do the job, so Im going to let him tackle it. Thanks once again. Rgrds Shaun[/quote]