netsatwork

I have been searching the forums, but have surprisingly not seen anything on this yet - I have a 2000 A4Q and when braking I hear a pop noise coming from both sides in the front. It started as a pop in the passenger side only, but recently the driver's side has started doing it too. I changed the pads and rotors on all four wheels a few weeks back, so I am leaning towards it being a suspension problem. I do not feel much of any feedback from the pop noise and it is really only noticeable with the windows down, but it is still pretty loud. The passenger side has been doing it for many months and there doesn't seem to be any problems with the handling or braking, but I'm getting worried now that the driver's side is doing it too.

To describe it more - I push the brake pedal and right when the brakes start to slow the car I get a quick pop from both sides. If I release the brake with the car moving and then press the brakes again, I will hear a pop again. If I press the brakes repeatedly with the car in park or neutral, the pop does not repeat.

Any ideas?

[ driven daily ]

I think we're experiencing the same thing with our vehicles, and it has to do with the calipers shifting within the caliper carriers. I asked my old shop (2Bennett Audimotive of Davis, CA) about this noise a couple of years back. The noise was most noticeable when I was backing out of a parking space, for instance, with the windows down and stereo off. Their thoughts, though never verified with a full, hands-on inspection/diagnosis, were that as the calipers grabbed the rotors, which are rotating either forwards or backwards, and because there was some slight play between the caliper and the carrier, the caliper was striking the inside top or bottom of the carrier, depending on which way the rotor was spinning.

This also explains why you wouldn't hear any noise while stationary. The cause? Worn and slightly stretched out caliper carriers that are, in my case, 15 years old. The fix? Probably new carriers, possibly new calipers as well to really tighten things up down there.

I can reproduce this noise very well by performing the following:
1. Reverse a few feet, apply brakes, caliper shifts slightly (should hear the pop)
2. Pull forward a few feet, apply brakes, caliper shifts slightly (should hear the pop)
3. Repeat.

Of course it very well may be something else. Hope this helps!

ThunderDent

Guys, my Q5 has this exact same issue. The audi tech's couldn't figure it out. My Audi specialty shop tech's think it's the carriers being flexed as well. Or possibly the bushings.

I had the calipers "professionally painted" and the guy painted the carriers and I think heated them. That is probably my issue. But I'm looking at $420 to replace them with new ones and may put that money toward new rotors if I can upgrade to the 2013's. Here's hoping!

But I have the EXACT same issues. Reverse about 15 feet. Loud pop. Forward, loud pop again, then everything is fine. It's really freaking annoying!