Does the iMac G5 get too hot?

Question

Greetings to all.
I would like to start a thread about the iMac G5 and heat. I found a few old threads, but I would like to bring that topic up again.
I have a 1st Generation iMac G5 (purchased end November 2004). For the second time since November 2004, it was defective and the Logicboard was replaced (so my Apple Dealer told me).
First time, in November 2005, the screen went pink. Second time, earlier this month, my Mac didn't boot anymore.
The full amount for the repair (including shipping to Apple (Belgium), work hours, etc.) was over 500.00 euro (about 700 USD for you, Americans).
I believe that the iMac G5 (at least: my 1st Gen one) is simply getting too warm.
The day before, I installed "Hardware Monitor". It gave the following (average) temperatures:
CPU: 60.6 - 63.8° Celsius (141-164° F)
HD: 57.5° C (135.5° F)
It is my opinion that the (my) iMac is getting too hot to be "healthy". I have 2 PC's, in which I installed extra fans (at the back and at the side). One of these, with an Athlon64 3000+ (1.8 GHz) and a 120 Gb Seagate Barracuda gives (average) temperatures for the:
CPU: 36.5° C (97.5° F)
HD: 26° C (78.5° F)
My second PC, an old (modded) HP Vectra, with an Intel P4 at 1.6 GHz and a 80 Gb Seagate Barracuda, gives as average temperature (HD only):
HD: 37° C (98° F)
It may not be correct to compare my iMac with PC's - but harddisks are harddisks, wheather it is a Western Digital (250 HD in my Mac) or a Seagate (PC HD's), and it is only logical that a(n average) HD temperature of 57 degrees Celsius (128° F) in the long term can not be healthy, while the harddisks of my PC's are a lot, lot cooler.
The PPC, too, gets much hotter than my Athlon CPU (and the P4 most likely too).
Therefor: is my suspicion correct that the/my iMac G5 in general is getting too hot for its own good? Even though it may be summer here (Belgium), I still find such a difference in heat values between my iMac and my PC's not "right".
Both the times that my iMac was defective, the Logicboard was replaced.
Is it possible that in both cases heat is the problem (directly or indirectly) of the defects of my iMac?
Basically we have a desktop computer constructed like a laptop, with all the hardware stuffed together in a very tight space. Why did they not keep the heat issue more in mind, when the iMac G5 was designed?
I believe that the heat is a very negative factor in the/my iMac G5. If I will have to pay such a small fortune, every time my Mac breaks down, being a Mac owner will become quite expensive.
iMac G5 (PPC), 17-inch, Superdrive, Mac OS X (10.4.10) 1.5 GB RAM, 250 Gb Western Digital HD
iMac G5 (PPC), 17-inch, Superdrive, Mac OS X (10.4.10) 1.5 GB RAM, 250 Gb WesternDigital HD
iMac G5 (PPC), 17-inch, Superdrive,   Mac OS X (10.4.10)   1.5 GB RAM, 250 Gb WesternDigital HD

Answer 1

Your Mac should have been repaired under the Apple power supply or video and power issues as long as your serial numbers were covered.
As far as normal operating temps are concerned, my Rev A is at this moment, running at CPU T-Diode 144∘and my Hard Drive is at 128∘so your temperatures seem well within normal ranges.
Yes, the machines tend to run a bit hot, but as long as the ambient temperature is not too high, they are fine. The failures were originally cause by a bad batch of capacitors but since those have mostly been replaced, the machines are much more reliable.
Some people train a small fan on the back of the computer to keep it cool, that may help you.
Miriam