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Discussion Starter #1
05 V, 87K, Original rear end etc. When driving normally - low RPM's around town - no problems. If I do any more spirited starts, just get the RPM's up a little starting off in 1st gear - I get "The Whine". Sounds like it is the rear end - like it is coming from the floor board of the back seat or under the back seats. The whine tracks the speed of the tires, ie it does not vary with the speed of the engine RPM's. It remains up through all of the gears and does not end - Until I come to a complete stop, put the car in neutral, and sit for while like at a long red light. If I start off again in a calm manner without getting into the higher RPM's, the whine is gone. It seems to appear only when hitting high RPM's in 1st or 2nd gear - if i meander through 1st & 2nd then get on it in 3rd or 4th, it does not start to whine.
Is it about to blow? any ideas? Thanks for any info.
 

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2005 CTS-V
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8,363 Posts
Nothing specifically complies with those variables. The usual suspects, driveshaft and differential are tied to wheel speed, but would presumably be "indifferent" as to whether a particular wheel speed had been achieved with high or low engine rpm. The flywheel/clutch assembly is, of course, affected by engine rpm but not wheel speed. My guess, assuming you still have a dual-mass flywheel, is that the springs in the dual mass flywheel are becoming fatigued such that they are affected temporarily by a high rpm episode.
 

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Discussion Starter #3
The car is Bone Stock - would the flywheel issue cause the noise from the rear of the car (probably showing a little ignorance here)? The thing that concerns me is the whine is LOUD. If it is the flywheel issue - is it a sign of impending doom, or just another lovable quirk?
 

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2005 CTS-V
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If it is the flywheel your clutch will likely fail (slip, starting in higher gears under load) before the flywheel does anything drastic. If the sound is coming from the rear, the likely cause is the differential. If it is the differential (or a drive shaft component) the sound will be much louder with the rear-seat trunk access door open. A noisy differential can still last many miles unless the internal gears are really worn. If the gears are really worn the metal content of the fluid will test high in a used oil analysis such as those available from Blackstone-Lab dot com.
 
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