Knocking in front end when braking, also when hitting some bumps

[pezgoon]

Alright, so I've got a new to me 2010 q5 with 160k miles on it. It was taken care of muuuuch less meticulously than my own cars are, but I was able to get it for half as much as any other options around here, so, that's good? I guess.... lol

What this means is though I am having to sort through a ton of shit that should've been fixed previously in its life but here I am!

So anyways, I've had a clunking in the front end. Originally I believed it was the lower control arm (only) bushings on the driver side, as one was completely torn and the control arm was literally hitting the subframe when I was braking and hitting bumps. Replaced those (both sides) well that sure as shit fixed A BUNCH of the knocking/slamming but now that it has been quieted down I have confirmed two new ones! yayyyy

The first is when I brake "hard" or pulse the brake pedal hard. The instant I do that I get a thud that I strongly believe to only be coming from the driver's side wheel area. I will have my wife drive me and repeat the tests so I can see if it's both sides or just the one. Searching the internet has been largely useless although I have heard vague mentioning of a TSB that directly mentions this issue. Talking about the brake pads being "too small" and allowing movement or something. Since it only happens with the initial application of the brakes, and only when forceful, I think there is some evidence that this might be the case. But I also can't find the TSB to see if that is what it actually describes. Along with that, I don't really know how to inspect or verify this and I don't think I can afford to just slap new pads in. I may look into it, but I've already invested quite a bit in parts so far.

Next! The "undulating" knocking. I am like 75% its sway bar related as I have experienced the same knocking once before on a ford focus and it was the sway bar, nearly exact sound, the difference being though that I was able to verify that the end links were bad because they moved. Maybe I am just not testing it properly, should I have the car in the air or not, should I have a jack under the wheel or something to lift some pressure off etc. Anyways, its not every bump but definitely any uneven bumps that give me the knocking and I am pretty sure I hear it from both sides, drivers may be worse but I can't tell.
When I was under there today with it in the air, I tried moving the end links, I inspected all 4 bushings in the end links and both sway bar mount bushings and honestly, they all look fine, no cracking at all which is terribly surprising. I don't particularly wanna throw 200$ at them if it isn't going to be the issue, so I am looking for some help diagnosing it. Honestly I have tugged and tried to move everything possible and I am just surprised that there is 0 movement at all in the end links if that is the issue.

I just had the thought, could it be the engine mounts? I did the trans service and the trans mount is fine, but honestly I haven't looked too closely at the engine mounts. I am sure they are bad, but I am just not sure if it would cause such a noise. Do keep in mind that the car spent at least the last 3 years in a city nearby me that I know has horrible road conditions everywhere so it definitely spent a large amount of time hitting tons of bumps and potholes so that's why I so strongly believe its the suspension.

Any suggestions will help.

[asiwa]

99% sure it's the upper arms based solely on your testimony.

I had a similar noise, though mine was a repetitive knock under braking. It started out as very infrequent and increased in volume and presence over the course of several months. This was between 100k and 110k miles or so.

When I took it for inspection, I told the tech exactly what I'd heard. Dude put it up in the air and claimed that "everything was tight". I asked him to actually drive it and listen, and when he came back and heard it only THEN did he say it needed one - not two or three or four - upper arm. Good news is that he put my stickers on before that diagnosis so I didn't have to redo my inspection...

When I finally took it apart to do the arms (the full set, upper and lower on both sides) the ball joints on the uppers were completely shot. The car needed four arms, not just one. Trying to wiggle them by hand while installed yielded zero play. It's just the way the suspension is set up on the car; it's really tough to diagnose play in the front arms and bushings unless they're completely destroyed.

I would also recommend doing a full refresh of the front arms on a car with that many miles (the back could probably use some love too). Even if they've been done once, you have no idea which ones and at what mileage. Worst case is that some of them have NEVER been done if it was as poorly maintained as you say. Never a better time to get it done!

Fingers crossed for your pinch bolts, too

Sent from my Pixel 7 Pro using Tapatalk

[pezgoon]

99% sure it's the upper arms based solely on your testimony.

I had a similar noise, though mine was a repetitive knock under braking. It started out as very infrequent and increased in volume and presence over the course of several months. This was between 100k and 110k miles or so.

When I took it for inspection, I told the tech exactly what I'd heard. Dude put it up in the air and claimed that "everything was tight". I asked him to actually drive it and listen, and when he came back and heard it only THEN did he say it needed one - not two or three or four - upper arm. Good news is that he put my stickers on before that diagnosis so I didn't have to redo my inspection...

When I finally took it apart to do the arms (the full set, upper and lower on both sides) the ball joints on the uppers were completely shot. The car needed four arms, not just one. Trying to wiggle them by hand while installed yielded zero play. It's just the way the suspension is set up on the car; it's really tough to diagnose play in the front arms and bushings unless they're completely destroyed.

I would also recommend doing a full refresh of the front arms on a car with that many miles (the back could probably use some love too). Even if they've been done once, you have no idea which ones and at what mileage. Worst case is that some of them have NEVER been done if it was as poorly maintained as you say. Never a better time to get it done!

Fingers crossed for your pinch bolts, too

Sent from my Pixel 7 Pro using Tapatalk

Sorry it took so long to respond. Honestly I read it the day you posted it I was just so upset I couldn’t respond lol.

I see your in PA I’m in Nh so both rust areas. What were your pinch bolts like? I’ve heard horror stories about them on my B7 A4 :(