Motor vibration and whining sound.

[Best Vette Yet]

I have a 2003 coupe, done 46000 miles. For a while I have noticed that when the vette is stationary, in neutral, and I rev the motor very slowly, there is a vibration felt which develops around 1300RPM and continues till 1800RPM then seems to smooth out. I also notice that this is the same RPM range used when cruising on the freeway at 70 MPH in 6th gear. Are there any other vettes with the same issue out there?
I also have a whine coming from the car at that RPM. It is not speed dependant but RPM dependent so that sort of rules out the drive train if I am correct in assuming. The whine sounds like the old "diff whine" but it seems to be emitting from the front of the vette. It occurs in the same RPM range as the vibration mentioned above.
There are no codes.

I have done a search on the forum and this seems to be a question other vette owners have asked but no replies have been posted. We would appreciate some thoughts on this topic if possible.

 

[Huskerman]

The whine could be the alternater going bad or power steering pump low on fluid or the belt tensinor pully maybe......the vibration I donno....

 

[tmkassin]

Check your harmonic balancer. They have been known to fail and can cause all kinds of issues. Put a light on it and rev the motor to the range you describe. If you see it wobble it is probably bad.

 

[Best Vette Yet]

Check your harmonic balancer. They have been known to fail and can cause all kinds of issues. Put a light on it and rev the motor to the range you describe. If you see it wobble it is probably bad.

By putting a light on it, are you referring to a timing light? I put that in series with plug #1? Been nearly 30 years that I have used a timing light. These high tech cars??? I will try that this weekend and report back. Thank you for the comments.

 

[Best Vette Yet]

The whine could be the alternater going bad or power steering pump low on fluid or the belt tensinor pully maybe......the vibration I donno....

The wine is deeper than you have described. It sounds like it is coming from the rear of the motor if I take a stethoscope and listen as close to the rear as I can get. Any other thoughts would be appreciated.

 

[Huskerman]

The wine is deeper than you have described. It sounds like it is coming from the rear of the motor if I take a stethoscope and listen as close to the rear as I can get. Any other thoughts would be appreciated.

Hmmmm......the torque tube sometimes will amplify sounds coming from the tranny or rear end forward.....just thinking out loud....