PMG5 Dual 2.0 CPU Fans Running at (very) different speeds

I purchased a refurbished PowerMac G5 Dual 2.0 from Apple 8-10 months ago and I always thought the fans ran louder than I expected. Recently, I opened the case and noticed that the bottom front CPU fan was running much slower than the top CPU fan (with the clear shield in place). I checked this with software and here is what I found...
CPUA ~ 300 rpm on average
CPUB ~ 3150 rpm on average
CPUA Temp ~ Amb 46C
CPUB Temp ~ Amb 37C
Nothing changed when switching from Highest Performance to Automatic. Is there a sensor that needs fixing/cleaning or should I take it in for service?
Thank you for your help!
-Will
PowerMac G5 Dual 2.0 - GeForce FX 5200 Model   Mac OS X (10.4.7)  

Yes take it in, this is a considerable difference.
There is only a few hundred (at most) RPM difference between my CPU A and B intake fans.
Either you got a dead processor or your fans need to be recalibrated or your firmware isn't right.
All three cases is a good reason to have Apple look at it.
It might be the software your using to read the fan speeds, download Hardware Monitor, it seems to be the most accurate and up to date.
I'm sure you have stressed the processors and checked in Activity monitor to see if both your CPU's are alive and kicking.

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