Drivetrain whine normal?

[avidmotion]

I have a used 35,500 mile Cpo SHO with PP. Had car 3 days 160 miles when , windshield wiper motor quit, p0456-purge valve code came on, stalling and a whine from back seat area. Took to local dealer. Had two weeks waiting on part, told me it was a PTU, but was a full rear axle assemble with new axles etc. At first I was happy to get car back. Windows open 70 degrees cruising along hearing that highway sound......next few days I thought I heard a whine again, but not everytime. I convinced myself it was nothing. I don't want to lose my car again. But today I could duplicate it everytime. Close windows, close moonroof, radio and AC off, wa la....instant whine in drivetrain, from 5 mph up you can hear it. It stays at same rpm sound, the pitch, even as speed progresses, it just gets louder. I have 3:16, does everyone's car make that drivetrain whine when everything all closed up and off? My 95 SHO didnt...is it just the AWD and it's normal? Only hear it under those conditions. Even if only moonroof is open can't hear it any longer. I just want to make sure before I do anything to the car, it is bone stock now

 

[ajpturbo]

Is drivetrain whine normal?

Lets think about this for a second......ok...survey says no

 

[FoMoCoSHO]

Since its in the back of the car and not rpm dependent I'm thinking possibly LPFP?

 

[ajpturbo]

Maybe they didnt fill the rdu?

 

[avidmotion]

If they did not fill the RDU I would imagine there to be some hidious noise from it. This sounds like from passenger front seat area. Has a gearbox kind of sound. Maybe normal that why I ask, my car is so quiet on level straight road, exce poo t the whine.....

 

[SHOdded]

Ok, so the PTU was untouched?  I'd definitely check fluid fill level.  Also check the wheel bearings on the right side, maybe it needs a hub/bearing job.  I have had a "whistling" sound happen when weatherstripping/mirrors have been moved around, but not a "whine".

 

[glock-coma]

I had a RDU fail but it took the dealer FOREVER to diagnose. My issue was a pulsing vibration from 55-80. They replaced everything in the rotating drivetrain. Then finally the RDU replacement fixed it.
There is a center driveshaft bearing that's part of the driveshaft assembly. But I would think it would change with rpm.

 

[Vortech347]

Mine whines just a hair when cold (winter, sub 40* temp) for about the first mile.  Up in the front.  Wife thinks I'm nuts because she can't hear it.

 

[SHOdded]

Wife thinks I'm nuts because she can't hear it.

Usually it's the other way 'round isn't it? LOL

 

[avidmotion]

It is definitely there, I tried to convince myself otherwise, sounds like a gear whine it don't change pitch just gets louder with speed, if you have good ears it starts around 5 mph, for sure hear it at 15, loud at 35 even for an old crotchy mechanic, by 60 it is humming right along.  Can reproduce everytime with radio and AC off and windows closed. It sounds like coming from front passenger seat area. If up to me I would change the PTU lube and trans fluid now at 36,000 miles. But want them b to deal with it and have on record. Wish this was not happening to me. I should have kept my G8, I did love that car and it was unique and ran awesome. But again wife hated it, damned if you do damned if you dont.

 

[SHOdded]

Make them give you a good-sized rental car while your car is in the shop.  Sucks though when you have to deal with these issues even with a CPO (though CPO is def no guarantee of 100% correctness).

 

[polskifacet]

I only have a little bit of whine if i do like a 0-60 run. The ptu fluid being even a little bit  low will whine louder than normal. Automatic trans also whines a bit compared to a manual trans.

 

[avidmotion]

...just an update....PTU and fluid replaced, rear diff and fluid replaced, still whines, might be the cheap chinese tires dealer put on