[danfratamico]

Last week, I replaced my severely shot front shocks, mounts, bump stops, bellows. After replacement, when I drive the car around for a bit I start to hear heavy squeaking/creaking coming from directly under the engine. I hear it mainly when I am traveling over uneven surfaces and when coming to a semi-pressured stop. I can even replicate it when pushing directly in the front-middle of the hood. I am thinking the new shocks are applying more pressure on the sway bar, hence the bar bushings may need to be replaced. I put my ear right up to them and they seem fine, unless the sound is resonating throughout the body of the car. It almost sounds like motor mounts but I only hear it when moving and not when I rev the engine or when it idles. Definitely suspension related. Any ideas? I am going to disconnect the sway bar linkages to test.

[Hoody007]

Sounds like sway bar bushings.
Had the same thing happen in an old Mercedes - replaced the sway bar and end links, and the noise went away.

[danfratamico]

Originally Posted by Hoody007

Sounds like sway bar bushings.
Had the same thing happen in an old Mercedes - replaced the sway bar and end links, and the noise went away.

I'm thinking more of the bar bushings. If the end links were bad, they would make more of a clunking sound rather than a rubber squeak right? I'm going to spray the end links and see.

[Hoody007]

Originally Posted by danfratamico

I'm thinking more of the bar bushings. If the end links were bad, they would make more of a clunking sound rather than a rubber squeak right? I'm going to spray the end links and see.

Yes, you're probably right.
On that car, I replaced both since it was 15 years old and had 185K on it.

FYI, there are BMW Performance bushings for maybe $5 more. Should be more durable, I would think…

[danfratamico]

Update: I drove around with both sway bar links removed and greased both sway bar bushings. Still makes the same noise. It is coming from both wheels. What could I have done wrong with mounting the shock and what are my next items to check? I don't think a ball join would make a deep creaking sound.

[mainbearing]

Did you loosen the lower control arms (tension strut and control arm)? And if so when you tightened everything back up, was the suspension loaded?

Another thing is to double check the strut rod nut is correctly tightened. What struts and mounts did you use?

The sway bar is not torsion loaded when both wheels of the axle travel together. Therefore I doubt pushing down on the middle of the hood (be careful the soft sheet metal) that the bar was the reason.

See the AutoDoc video I linked in this post, 4:23 into the video:
https://www.e90post.com/forums/showp...1&postcount=13

[danfratamico]

Originally Posted by mainbearing

Did you loosen the lower control arms (tension strut and wish bone)? And if so when you tightened everything back up, was the suspension loaded?

Another thing is to double check the strut rod nut is correctly tightened. What struts and mounts did you use?

The sway bar is not torsion loaded when both wheels of the axle travel together. Therefore I doubt pushing down on the middle of the hood (be careful the soft sheet metal) that the bar was the reason.

See the AutoDoc video I linked in this post, 4:23 into the video:
https://www.e90post.com/forums/showp...1&postcount=13

Yes, the large control arms were loosened and retightened after assembly with the car lowered. Yes, the strut mount nuts were properly tightened - first tightening by hand with a socket and Torx bit then final tightening with an impact gun. I used Bilstein touring shocks and Sachs strut mounts.

I just used grease on the sway bar end links as well as the top and bottom shock pads. Still making the same noise. What is very odd is that it sounds like the noise is coming from the center of the vehicle, sort of under the oil pan. Makes zero sense, especially after a shock replacement. Sometimes I can replicate the noise when everything is cold, but I hear it a lot more when I drive around for at least 2 minutes.

[danfratamico]

Update: The lower control arm was the cause of the squeaking. I neglected to mention that I did replace the large control arm bushings but did not replace the lower control arm. I also lowered the wheel assembly without loosening either of the two control arms. I'm guessing this caused internal damage to the lower control arm. If I leave this control arm loosened, it does not make the noise. Safe to drive like this or does this arm need to be torqued under load as well?

[mainbearing]

BMW's recommendation when replacing struts is to loosen the inner mounting nuts and bolts for the two lower arms. This allows for more downward movement of the knuckle for the strut assemblies to clear the fender well. And if you force the knuckle down for the strut assembly to clear, then that can place more stress on the rubber bushings. It may or may not damage them, depending on age I suppose.

The movement on the bushings is limited, and too much can cause them to tear. If you loosened the mounting nuts and bolts, then they need to be torqued with the suspension loaded, as in the AutoDoc video above.

I would only drive with everything properly installed and torqued down.

And how easy was replacing the large bushings by themselves? I should do mine as well if not replacing the entire tension strut.

Picture of the lower arms. Tension struts on the outside and control arms on the inside.