Is my Mac dying on me?

[TonyDA]

Having had my G5 for a couple of years, it's developed an intermittent fault over the past few months:

If I leave the machine on for a long period of time, for example overnight, on many occasions the tower will start to make an extremely loud noise, like an aircraft taking off! The mac also crashes when this happens.

It only happens if the mac is left on, but untouched, for a long period, but doesn't happen every time I do this. Also, I can have the machine on for hours during the day, using it, and the fault doesn't occur; leave it on overnight, or go out and leave it on, and the noise may occur.

Any suggestions as to what's wrong? Is it a dodgy fan, or something worse?

Thanks
Tony

[Distant Cousin]

I can't offer any advice but it seems very odd to me that it only crashes when you're not using it =/
I'd have thought that'd be when it's least likely to crash.

[bingowings]

sounds like it's overheating for some reason - might be worth opening it up to see if it needs a clean. my G4 was black inside as the mate i bought it from had it sitting on the floor, and it was hoovering up all kinds of crap.

[TonyDA]

Distant Cousin - Yep, I agree. Then again, I left in on last night and it didn't do it at all, so go figure!

Bingowings - ta for that, will have a look later on. Think the G5 is easy to open...