tick-tick chassis noise - ideas anyone?

A6 All/ S6 All
#1

I am hearing quiet “tick-tick” on the left side followed by a matching “tick-tick” on the right from somewhere behind the driver. It usually happens after I slowly accelerate from a stop, in stop & go traffic, or after a speed bump. It sounds like the tires are kicking up a pebble, but the tone and rhythm of the “tick-tick” is always consistent and it always travels left-to-right so it must be something mechanical attached to the chassis.

I tried to record on my iPhone but it is not loud enough.

It could be a complete coincidence, but I noticed it after I had pads and rotors replaced. But we looked at the brakes and suspension and there is nothing obviously wrong/loose.

any ideas?

#2

What you’re describing sounds to me like axle noise. Check your inner axle boots would be my first suggestion. The other thing I think of is suspension (spring) bind/sway bar end link noise.

Excuse my ignorance on the S6 chassis. Is there a subframe? I just bought a D3 S8 last week so I’m new until I start digging and taking it apart. And I plan to hang out here due to the traffic compared to the S8 subforum.

#3

trillypop welcome maybe concider making a new member post and put up some pictures

#4

Dose the noise get faster and faster as the car accelerates. If its comming from behind your seat It might be the exhaust getting into contact with the drive shaft. but there will be other things it can be. If we start working through all the things that are going on we should be able to get to the bottom. Other then brakes did you get any other work done recently

#5

Do you have slotted brake disks?

One of my disks has a very slight warping to it, so one of the slots hit the brake pad on each rotation, making a tick-tick-tick sound. The sounds goes away when I hit the brakes (or rather, get’s muffled by the sound of all the rotor slots hitting all the brake pads), then comes back when I let off the brakes. It never bothered me enough to do anything about it.

#6

No, not faster and no other work in that timeframe - although, since then the intake manifold was carbon cleaned and broken flaps removed… And no slotted brake discs, just hi-carbon centric

I only hear the “tick-tick” once traveling from left-right as I add throttle after a stop or rolling stop. I don’t hear it once I’m up to speed - but then it might be hidden by the roar of the engine. It doesn’t seem to be related to wheel or axle rotation.

Maybe as the chassis weight moves to the rear on initial throttle? But it’s not heavy accel - stop 'n go driving is enough to trigger. But the left-right nature makes me think it’s something like an anti-rollbar. But I don’t know enough about what is happening under the car.

#7

It sounds just like tires kicking up loose pebbles. But it’s so consistent and repeatable that it couldn’t be that.

#8

This is kinda hard to pin down. Sounds like it can be in the suspension. Is the sound at a constant rate and what pace would you put the noise. Is the clicking a constant clicking or speratic

#9

I can hear it maybe 50% of the time I move forward in stop and go traffic. Maybe takes 1 sec to go from left - right. here is a sound file where you can barely hear it over the engine noise. But it’s not in stereo so it won’t travel from side to side.

https://clyp.it/0sul4al1

#10

I wasnt able to make anything out. Im going to try and plug in later with my head phones and see if I can hear anything

#11

I listened to it a few times and it sounds like plastic dash or interior noise. You said it feels like its located under the car so that kinda rules out the dash. Something that loud can you hear it more if you have the windows down or if you have the windows up

#12

It’s hard to hear with the windows up because the sound is masked by wind/road/engine noise. But from the passenger seat it seems to be coming from a location at about the middle of the car (b-pillar) - but still a left-to-right sound. Again, it only occurs on initial launch from a stop or rolling stop (i.e. stop and go traffic).

The left-right nature of the sound is so consistent I’m guessing it has to be something like a roll-bar or maybe engine/transmission mount??? But is there anything that would possibly be in the middle of the car?

#13

Get under there and shake anything you can (exhaust, heat shields, etc).

#14

I’ve recently been having problems with my anti-theft system - sometimes I try to start the car and I get a random ‘parking brake’ fault and the car won’t start because the fuel is cutoff. My mechanic taught me to lock the door - wait 5 minutes for the anti-theft system to reset, and voila(!) it starts again.

The last time this happened, I was clicking the lock/un-lock on my key and it sounded remarkably like the tick-tick sound. And this morning, I finally made the connection - I pressed the “lock” button on the door while the car was already moving and it was the EXACT SAME sound that was haunting me from above.

Apparently, the car does not register that the doors are locked and it continues to auto-lock the car in stop-n-go traffic. I also noticed that the lights no-longer blink when the car is locked by the key, but they do blink when un-locked.

Now I know what is wrong, but does anyone have insight into what is happening and a possible fix?

#15

Depending on the system it might be the pump in the trunk area. That trunk pump bulds pressure and locks and unlocks the doors at your request. You can stock the constant locking by going into vag com and turning off the auto lock function when you hit a specific speed. Also when your in vag com check the central locking module for codes. It should lead you in the area of whats wrong