Fan noise in a G5

:confused I have a G5 with a single processor. When I first bought it the Mac was very quiet. My problem is now the fans go crazy almost immediately after start up or activating from sleep mode. I'm running OSX Safari, I'm not computer geek so I may look stupid. I'm just a user that likes the Mac and wants it to work correctly like it used to. I put in a temp monitor utility and it says CPU temp avg. is 130-135 deg. Bay temps are ambient. Relocated computer for better airflow, tried a PRAM zap (whetever that is) per advice from cousin. Didn't help. I would appreciate any advice for this dummy on what to do next. Thanks

My dual G5 does that too since 10.4.4, and still does it with 10.4.5.
It only does that when CPU performance is set to automatic. If you set it to reduced or highest, the fans won't go up unless it is really needed.
In automatic mode it seems to always try to keep the temps at a certain value, and thus blowing full blast every time the CPU get's used a lot, even if it's only for a very short moment.

To change that setting, go to System Preferences -> Energy Saver. Click the Options tab and there you see the Processor Performance setting.

Tried that in reduced, enhanced and automatic. No Change. Now the temps are hitting over 160 with drive bays at 92 deg. Mac goes nuts and starts partially shutting off. I have to shut it down quick before it fries itself ! It's not located in a confined space.

My Quad G5 does not have this problem on a regular basis only when the computer is not responding or when I when I am seriously using it for hours.. What are you doing on your computer normally, and are any programs locking up when this is happening?

What operating system are you running 10.?.?