Anybody heard the, "Bilstein knock"?

[SoupAnxiety]

My BMW E92 is sat on fresh (<20,000 mile old) suspension components - bushes, arms, struts, springs. For around 10,000 miles there's been a creak / knock from the front. It's present all the time, but especially noticable when coasting to a stop / setting off, driving on uneven roads and driving in warmer ambient temperatures.

I've tried PTFE on the suspension bushes I can get at in case there was an angry suspension bush, but it didn't help. I'm not due a service for a while and although it's only a niggle, it's annoying!

The struts are Bilstein B8s and the springs Eibach. There are plenty of folks online talking about the, "Bilstein knock" developing after having some Bilstein components fitted. It's an annoyance apparently, rather than a defect. Does the above line up with this?

I appreciate it could be anything and it's hard to diagnose from my ramblings, but pointers would be welcome!

[jkh112]

Not heard of it before. My car had all new bilstein suspension a few years ago and no knocking.

[Butter Face]

Funny you should ask this, I’m currently experiencing the same thing.

I have Bilstein B8 and Eibach Pro Springs and have the odd knock, it’s very intermittent, some days it’s knocks it’s tits off, others not a peep.

I’ve been convincing myself it’s the top mount, but having read some stuff I think it’s just the shocks and I’m going to have to live with it.

[SoupAnxiety]

Butter Face said:

Funny you should ask this, I’m currently experiencing the same thing.

I have Bilstein B8 and Eibach Pro Springs and have the odd knock, it’s very intermittent, some days it’s knocks it’s tits off, others not a peep.

I’ve been convincing myself it’s the top mount, but having read some stuff I think it’s just the shocks and I’m going to have to live with it.

I'm not alone!!! Thank-you for restoring my faith in my sanity.

I thought top mounts, but my mechanic can't find anything wrong with these or components elsewhere.

The warmer weather has made it much more noticable, it seems to be linked to ambient temperature rather than component temperature.

It does seem to be a Bilstein quirk from what I can find. The setup works brilliantly for me and rides great, just a shame about this knocking.

[Butter Face]

Yes we’ve already done top mounts once, I won’t be doing it again!

Have you had your car up in the air with the wheels still on and moved the shock around? The inner tube (if you know what I mean) has play in it with no weight on it, but when it’s down there’s movement. I had this verbally confirmed to me by Bilstein as correct last year.

The knock is annoying, I am half tempted to change the shocks but as you’ve said they are a great setup!

[jimmy the hat]

Mine was my top-mounts. I appreciate that not everybody's will be so if you've changed yours and are happy that they're fine, they probably are.

B8s and Eibach Sportlines, it was the shock turning and the spring staying still, causing a creak when the plastic sleeve on the end of the spring rubbed on the spring cup. Stuck some new, heavily greased, top-mount bearings on. Smooth as silk.

Any checks need to be done at ride-height, as soon as you jack it up and unload it all everything's in a different place to when (where) it makes the noise.

Cheers, Jim

[SoupAnxiety]

jimmy the hat said:

B8s and Eibach Sportlines, it was the shock turning and the spring staying still, causing a creak when the plastic sleeve on the end of the spring rubbed on the spring cup. Stuck some new, heavily greased, top-mount bearings on. Smooth as silk.

Thanks for this. Sounds plausible, my top mounts have been checked but I don't think they are greased. Can they be removed, greased and reseated without requiring suspension realignment?

[loose cannon]

I fitted a bilstein kit and eibach springs to my e46 touring and found the rear shock dust covers would knock and clang around over bumps so I removed them and the problem dissapeared with them

[The Wookie]

Dry ARB bushes?