Rumbling
02-12-2018, 10:46 AM
#1
Instructor
Thread Starter
Rumbling
I am going to do my best to describe my noise. 2009, A6, Z51 and the car is stock with 75000 miles. It has a rumbling noise that starts when the car warms up and only under acceleration. I have tried running it up on blocks, driving down the road with the door open and standing on the side of the road while a friend drove by, no noise. I checked the rear hubs, axles and the exhaust system, nothing. Any ideas?
02-12-2018, 11:28 AM
#2
Team Owner
Member Since: Mar 2004
Location: Oklahoma City OK
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C6 of Year Finalist (appearance mods) 2019
Exhaust pipes hitting on something under the car?
02-12-2018, 03:15 PM
#5
Le Mans Master
I am going to do my best to describe my noise. 2009, A6, Z51 and the car is stock with 75000 miles. It has a rumbling noise that starts when the car warms up and only under acceleration. I have tried running it up on blocks, driving down the road with the door open and standing on the side of the road while a friend drove by, no noise. I checked the rear hubs, axles and the exhaust system, nothing. Any ideas?
02-13-2018, 08:40 PM
#10
Melting Slicks
Member Since: Jul 2014
Location: The Lowcountry South Carolina
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Go to a GM dealer and look up the service history on the VIN. Likely something in its past, having only owned for a relatively short time. Did you get a car fax upon buying? Have you seen it from the bottom side, upon a lift? .... look to it’s past.
02-13-2018, 09:09 PM
#11
When you had it on the lift, did you check the motor mounts? If one is broken, you could have the torque of the engine causing something to touch that shouldn't...
PS: How is PP these days? I went to Dixie Hollins
PS: How is PP these days? I went to Dixie Hollins
Last edited by RogerRamjet21; 02-13-2018 at 09:10 PM. Reason: Additional information
02-14-2018, 12:46 PM
#12
Melting Slicks
If the you can feel the rumbling as a mild vibration and especially if it's reduced after an upshift, it could be a worn or failing clutch in your A6 transmission. 75k miles is a little early for this, but it's been known to happen.
On the other hand, if the rumbling is not mild at all and is worst at about 2,000 rpm, 4,000 rpm, etc., then it could very well be your harmonic balancer.
On the other hand, if the rumbling is not mild at all and is worst at about 2,000 rpm, 4,000 rpm, etc., then it could very well be your harmonic balancer.
03-02-2018, 02:28 PM
#18
Le Mans Master
These cars "warm up" very quickly, often within a mile or so. Saying it only happens when the car is warm does not mean much unless you have tested it for the symptom immediately upon starting. Please let us know if it also happens when cold.
Most of the symptoms people have suggested would occur regardless of op temp., such as motor mount/HB. Heck, it could be a wheel that is just very slightly loose. Or, it could be a bad differential, or many other things.
When you find out what it is, be sure to let us know.
Most of the symptoms people have suggested would occur regardless of op temp., such as motor mount/HB. Heck, it could be a wheel that is just very slightly loose. Or, it could be a bad differential, or many other things.
When you find out what it is, be sure to let us know.
