E46 knocking sound

[John_D]

Hi all,
Trying to track down an annoying knocking sound, sounds like it's coming from the floor area or perhaps bulkhead.
I've checked everything within reason. All arb bushes and drop links are ok, no slackness in suspension. Car is super tight on the road. Exhaust is mounted firm, front bracket hanger is in good condition, no loose bolts on control arm bushes or subframe reenforcement .

All out of ideas, any thoughts or suggestions?

You only hear it at low speeds and usually over bumps or undulations when at steady speed not usually while accelerating or deceleration.

[HealyC]

Front anti roll bar rubbers John, mine went the same but very hard to see them gone when there on the car

[John_D]

I did them two years ago Conor, they are still fresh.. Ish. Suspension is all dead tight, car feels solid.

[Venom]

I did them two years ago Conor, they are still fresh.. Ish. Suspension is all dead tight, car feels solid.

how are your mounts for drive train?

[John_D]

No obvious movement, new rear diff bushing just fitted. Like I say the car is solid, if it was a suspension bush or mount I'd definitely feel it.. Trouble is I can't feel any knocking to coincide with the sound. I'm thinking it's something 'ancillary' like a bracket or something but just can't find it

[John_D]

Update, I had a good poke around the engine bay. There is significant play in the steering u-joint, I can replicate the knocking by moving it with my hand.
I still am surprised I didn't feel the knocking through the steering wheel!

[John_D]

Turns out it was just a worn droplink. I feel like a tool I should have investigated them properly in the first place. The movement was tiny but enough to cause a racket.
All sorted now.

[DJ Genius]

Glad to hear that. I was just about to suggest to check the drop links again as clicking/knocking noises over bumps and stops is 95% drop links. And they need to be checked thoroughly as they might look good, but are really shot.