Question about Strut bearings

[ArdAtak]

Hi Everyone,
New Audi owner here. I have a 2009 A4 Quattro with 2.0 Liter, 4 cylinder engine.

I've been hearing an odd knocking sound from the front left suspension when I go over speed bumps and sometimes when accelerating or going uphill (I guess anything that causes lift to the front end). I took it to 2 different mechanics and both claimed they couldn't repro the issue but visual inspection of everything (control arms, strut mounts, etc.) was solid and everything seemed OK. In both cases, I had to drive the vehicle to show them the noise and they just defaulted to the problem being the struts, more by process of elimination and the fact that the inside of the struts is the only thing they can't see.

But just based on the nature of the sound, I have a suspicion that it might be the strut bearings, but I might be speaking out of ignorance since when I went to inspect the strut bearings from under the hood and all I saw was a metallic mound which is basically the same color and part of the car body. I was expecting to see a plastic cap that I could remove and see the strut bearing. But this wasn't the case. I could still see the 4 strut mount bolts. 2 of them accessible directly and the 2 closer to the windshield require removal of the weather strip and plastic cover by the windshield. They also require removal of the windshield wiper fluid pour tank (not the container itself) if you want to work on them.

I can post pictures if anyone's interested but I suspect you experts know what I'm talking about.

My question is: Is there even a strut bearing in this scenario? If so, how does one access it? Also, can the problem be anything other than struts? I could be wrong but I feel that the diagnosis by the mechanics was a bit lazy and uninformed (neither specialized in European cars).

Any advice would be greatly appreciated.

[Luis_Heineken]

Strut bearing

https://www.ecstuning.com/b-genuine-...ch/8k0412377c/

check control arms

[ArdAtak]

Thanks. Would lubricating the joints and connections be appropriate? Any downside? What's the best lube to use?

[Jacon]

Subscribed.

I started noticing the same problem on my 09 about 4 weeks ago. The noise comes and goes and isn't predictable with every bump I go over or steering input I give the car.

IIRC, the suspensions for these cars are contained to almost one 'unit' that can be removed once all the control arms are disconnected. I believe the bearing rides underneath the 'cup' you're describing. Someone with a picture should help out.

I'm at 107K miles on my KW coilovers with original strut bearings.

[Luis_Heineken]

Thanks. Would lubricating the joints and connections be appropriate? Any downside? What's the best lube to use?

No, they just break, thats why the knock sound

[ArdAtak]

So if it's cracked bushings is replacing the entire strut the best way to go? Or just replace the bushings?

[CONative]

I can confirm the front suspension is 'contained to one unit' - had some pics of mine when I was installing the Bilstein kit earlier this summer - not the easiest to remove.

OP - how many miles on your Avant?


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[U_know_me]

It is assembled as one unit, see page 15

What you are describing is generally the shock, tie rod end link, or the control and not the bearing, since you had it all inspected I would bet it is your shock. The bearing will generally pop when you turn and you can usually test it by turning the steering wheel while stationary and listening for pops or creaks. If you have anything over 100k miles I would not be surprised that your shock has gone bad. If you decide to replace the shock I would be sure that the bearings are replaced at the same time.