FiZzd

We might be stumbling onto something here..

Tell me if yours is an automatic, and check the tensioner see if it bounces up and down when the noise is happening, and gas it a little .. if it stops ... than ... we can continue.... the alternator from France has me intrigue..

Choreo

I do have an automatic. I still need to get someone to help check the tensioner.

I only have 37,000 miles, but 8-years is a long time I would guess for a tensioner to hold it's spring!

FiZzd

Alright... lets get started!!!

Look at your tensioner & let me know if its bouncing up and down (when its making the noise)

Let me know when you gas it a bit... does it stop

Choreo

Got everything all set up with a mirror so that I could watch it this afternoon and of course I could not get it to vibrate once in any gear. So I gave up, put the hood down and as soon as I got the street corner it started rattling like my brain after my last female experience.

I will try again tonight - it may just be shy and won't do it with the hood up.

HP3

I have this same exact problem

FiZzd

here a tip .. to see if it really rattles, turn your lights on, ac on, put it in reverse....

watch it rattle....

Choreo

Just installed new tensioner, idler pulley and Gatorback serpentine belt - just to see if that might not be part of the problem with my voltage dropping momentarily when coming to a stop. No difference. Apparently my old belt, tensioner and idler were performing fine.

Very slight movement in the tensioner arm at idle which is normal.

RedRckC5

got the same problem on my 03. She would stutter and shake after a drive at a stop light and also with the ac on on reverse. I vote for the alternator. Going to the dealer (under warranty) next week to check it out.

Choreo

Already replaced my alternator with a new GM unit last month, also replaced battery and ignition switch. Still dropping voltage when I come to a stop.

RedRckC5

Check the connection and the battery. My voltage would drop after i put in a new battery and realized that it was a bad battery. The 2nd time, my connection was loose. Good luck.

robsc501

Hi There:
Wow! your car has really low miles. 4k on the clock & 8 years as a garage queen.I would rule out the alternator as the problem. Because of the low miles I would be checking the fluid level of the a/t transmission & shifting plate for security or being bent.All your drive & a/c belts have long exceeded their self life. I would inspect them for weather cracking & change all of them, then you will at least have a good starting point if the problem still persists.Next I would be looking at the belt tensioner.
robsc501

Steve Davis 706

I have read quite a few threads on here and never took time to set up account, finally took time so I could throw out my 2 cents. but never seen someone say they found problem with vibration in reverse and drive in A4. But I'm glad to say I finished replacing my old motor mounts today and problem fixed. You can see in pic a good difference in height. Mine is a 97 with 150k and mounts were not broke visually but all these years holding up this LS1 they just were hard and shrunken. Which while I was in there i went ahead and installed a underdrive dampener and still have 14.2 volts at idle. Couple of you guys post had me nervous about underdrive dampener but so far only Con is power steering but I'll get use to it.
And I would like to thank you guys for all post I've read and learned from. But there have been quite a few I tried to comment on where problem seemed obvious but was sent to set up acct and just never took time.
One post on here i remember was a guy with a manual with a bad vibration and believe it didn't do it until he had new clutch installed. And his clutch didn't last long and shop had him return it but not sure what happened from there. But it sounded like someone left a dowl pin out and I'm sure the shop would never admit it.

Vetteman Jack

formvman

Just saw your posting on Vette noise. My noise only occurs at low rpm at 500 or below. How did you ever resolve it? thanks

kh400

Put it on a drive-on lift and sit in the car in the air and have someone underneath looking for the problem. Basic NVH. Good luck!