Suspension noise after coilover install - any pointers as to what it may be?

Hello

First of car is a 2011 335is with about 105KM.

I get this noise. Started after coil over install. My top mounts are torqued to spec. Everything is torqued to spec. It does the noise only sometimes , and only when bringing back the steering from almost full lock right, as you can see in the video.

I was about to remove my end links and drive as an easy way to rule them out see if noise is still there. Any other ideas what it may be? Maybe because I re-used old top mounts?

If you know which side the noise is coming from, and there’s nothing obviously wrong, put the old parts back in on that side as a test. Only a test, don’t drive with a mixed set of suspension parts. If the noise goes away you know there’s something faulty with those new parts on that side.

I guess I am not hearing the right noise. Sounded like it was something in the steering column.

i assume you have a pic of new strut assy’s? maybe from website? what does your old strut assy look like as a comparison?

Some people say it might be coil bind?

Well, it’s different for sure.

I don’t really have a whole assembled pic of the old stuff.

If what you are calling coil-overs are what I think, coil-overs are noisy. Are they these;

image

The springs can rub the threaded portion.

If it isn’t the spring, I’d guess the stab bar links were “spun” with an impact wrench during the install. Makes them immediately noisy.

Yes those are coilovers, mine speceifically are these.

What do you mean by stab bar links? Sway bar end links?

Yup, stab bar links = sway bar links.

One of the better kits, IMHO but the threaded collars need to be tight once set to the proper ride height (lowered or stock). The springs can still rub up towards the top, as well. You said you used the original top mounts… are you sure they were in good condition?

Yeah I did impact them off. When I’ll take them of that will rule 'em out.

I’ll double check to make sure it’s tight and the coil seats ok.

And yeah, they look ok, the rubber at the bottom seemed thick (on these cars the rubber gets thinner) and I spinned it on and did not feel to much grit/resistance. Was spinning smoothly.

When you impact wrench thenlinks, you must hold the stud so it doesn’t spin. If it does, it wears out the inners and causes clunks.

Is this the stud which goes through the center of the cylindrical bushing? Wouldn’t shops normally avoid spinning that stud as a matter of course? Since it is pretty obvious the threads moving against inner surface of the bushing could enlarge or otherwise damage it, sort of like a drill bit would?

I believe your suspension actually turns the strut when you turn the wheel… Some are setup this way and some are not, but if I recall correctly your strut does turn with the steering wheel as BMW was rather fond of this setup for many models and years. This adds quite a few things to look for on the side that is noisy. It could be the top strut mount bearing that allows the strut to turn with the wheel. It could be that the spindle is not tightened properly to grip the strut base…or the strut is not seated all the way down into the spindle mount. The spring might also not be seated properly…meaning the ends of the spring are not in their contoured mount cushion, etc… You have plenty of things you look into here…

The stab bar links that attach to the struts themselves are little ball joints. Like @Honda_Blackbird writes, they turn when you steer and the rotate with suspension movement.

Typically, the ones I have seen have either an allen hex or Torx inside the stud end or a hex on the outside to allow you to hold the stud to tighten or loosen the torque prevailing nuts. Those nuts don’t usually want to come off easily so it is common to hit the nut with an impact wrench to break them free. You can’t hold the stud when you do that so it spins the joint which wears out the nylon/torlon/plastic inner part and causes clunks.

Replacements often have a hex on the backside so you can hold it while using an impact and they often have grease fittings, too.

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Correct. My top plate turns with the car so yes a lot of things with the strut itself could be wrong.

I’ll remove both end links this week end and test it, if it doesn’t work I’ll try see if I can open the top plate off without removing my shock out