Knocking sound from rear right of my Audi A4 2005

[Johann]

Hi Eric.

I am in need of your help.

I have this knocking sound (sounds like metal to metal) when going over bumpy roads and uneven surfaces. I hear it coming from the rear right of my car. Sometimes when I accelerate and brake I hear it to. This sound is now beginning to really irritate me because I can’t enjoy my car any more. It’s an Audi A4 2005 B7 Executive.

I’ve gone to a local mechanic and he found nothing. Me not so easily convinced jacked up the car and did a inspection myself. I checked everything and every bushing seems fine. But when I inspected the rear sub frame bushing situated at the right where the sound is coming from. I found this. See attached picture.

Can this be the cause of my knocking sound Eric?

To me the bushing really looks in a bad condition.

Thanks a lot

Attachments:

• IMG_20140530_152010.jpg

Topic

[EricTheCarGuy]

Looking at your picture I’d say that’s a prime suspect. You might try removing just the one bolt to inspect the bushing. If it’s the sub frame as you say, the other fasteners should hold it in place just fine if you only remove the one bolt. If the bushing is damaged, replace it, which may require removal of the entire assembly, and then recheck for the noise.

Good luck and keep us posted. Additional information here if you’re interested.

http://www.ericthecarguy.com/faq/diagnosing-noises-in-your-car

[Jamie]

That would also me by first suspect. Espessialy with the noise being there on accel or de-accel. First things first check the bolts for the sub frame are tight. Unless your car has been lowered you should be able to roll a jack under the sub frame beside that mount and put lifting pressure on it, you don’t have to lift the car off the ground. Watch for any movement in the mount. You can compare it to the other side as well. You can also watch it while someone jumps up and down on the back seat, or in the trunk.

At 9 years its a bit early for it to fall apart like that unless the bolt was loose at some point. but different road and weather conditions have effect on rubber bushings.

If you replace it and the sound goes away do all the other ones as well, you want to have even balance. Even if you drive through salt daily the bolt shouldn’t be too corroded as most those are a high grade coated bolt. A half inch ratchet and socket will work. Re install with medium thread lock.

[Author]

Replies