Hello guys,

I've got a real head scratcher for you that I have been trying to research/figure out what is going on.
I have a 2003 C5, approx 48k mi on it. Completely stock, nothing is changed on it, other than tires.

Probably a month or so ago, it developed a noise on a long trip (approx 300 mi) that I couldn't quite place, as I could only hear it after approx 100 or so miles. After parking the car over night, the sound went away the next day, until I had drive 100-150 mi back to my house. The last few weeks, it has taken less and less time for the noise to start, usually by the time the oil hits 137f and water is at 187f. Now for the confusing characteristics of the noise.

Speed: At roughly 57+ mph
RPM: Rpms corresponding to 5 and 6th gear, at the speed above, any other gear and the exhaust covers it I believe.
Location: Hard to place inside the cabin, but I believe it coming from the rear. Again, hard to tell.
Sound characteristics: Oscillating mechanical sound, kind of a wurrr sound.
Gas pedal position: Accelerating(Gaining speed) - minor noise, mostly exhaust. Constant(Holding speed) - Very apparent. Decelerating(Losing speed) - Noise absolutely 100% gone.
Clutch position: At constant speed, in - Noise absolutely 100% gone, out - Very apparent.

I jacked the car up this morning after my shift, and found this.

Engine running, clutch in - nothing but sweet ls1 purring.
Engine running, clutch out, in neutral - metallic clackity noise coming mostly from around the TT-Trans join.
Engine running, clutch out, in first - Less metallic clackity noise, "pops" every so often from drive train.

Any thoughts? This is really driving me crazy. Thanks guys.

r2h


P.S. If anyone is in the Baton Rouge, LA area and wants to lend another ear/perspective just message me and we can meet up. This is my first and only corvette and would be nice to see what another owner says/thinks of my car and it's crazy noises, and maybe a beer or two.

 

maybe CV Joint wearing out.... i know that not very likely at all with your year, milage and seeing as your car is stock. you might try grabbing the axle and seeing if you can move it to see if there is play

 

When it cools down (just got done running hard ), I'll go out and give them a good shaking. Wheel bearings feel good and tight.

Also, bump for more suggestions on what to check

r2h

 

Sounds to me like you should leave the wife home on these trips. Let us know if the noise goes away.

 

Might add ...changing the diff. fluid to your list. Rear wheel bearing on the C5 will be difficult to isolate out sometimes.

 

Wish it were her making all the noise!

 

Change probably about 10k miles ago. Amsoil

 

Gave the back axles a good shaking and could not discern any play in them. Anything else I could try to diagnose the diff/axles?

I found this on another forum, any input related to it?
Low pitched "card in the spokes" is a very good way of describing this sound.