Suspension noise diagnosis

[nsk040]

I need to do the suspension refresh - plan on doing this one http://www.zhpmafia.com/forums/showthread.php?16182-Help-with-Suspension-Refresh-at-50k-miles-10-years however probably will skip the front control arms as those were done a while back - but haven't gotten around to it given a very short commute.

I've noticed my car seems to make a knocking noise going over most bumps. A partially depressed manhole cover is a good example of something that would produce a slight knock/thud from the suspension, not the tire itself.

Will this go away post-refresh most likely? Any likely suspects r.e. what's causing the noise?

Thanks

[san]

Is the noise from the front or the rear?

If front, then could be fcabs, end links or the strut mounts

If rear, then similarly could be rtabs, end links or the shock mounts themselves...




Sent from my iPhone using Tapatalk

[nsk040]

I'm inclined to say front. But since front is what hits the bump first maybe that's just what I hear more. Sounds like all of those items - with the possible exception of FCABs which I replaced not too long ago - are going to be replaced with the refresh so it should go away.

Any Charlotte, NC located members with adequate tools want to help me with the DIY? Would love to learn about working on these cars and happy to make it worth your while.

[ZHPizza]

I'm inclined to say front. But since front is what hits the bump first maybe that's just what I hear more. Sounds like all of those items - with the possible exception of FCABs which I replaced not too long ago - are going to be replaced with the refresh so it should go away.

Any Charlotte, NC located members with adequate tools want to help me with the DIY? Would love to learn about working on these cars and happy to make it worth your while.

Uptown Charlotte checking in with more tools than time. You can borrow anything you need, but me finding the time to help is more difficult. Spenser is in South Charlotte and has a similar clunk that he's chasing. Maybe you guys could compare?

[704sw]

As Pizza mentioned, I'm down in South Charlotte near Ballantyne. I'm starting operation suspension overhaul soon, and I too am chasing down a phantom sound. I have a couple ideas, but I'm happy to compare sounds and see if we can chase it down.

[slater]

I need to do the suspension refresh - plan on doing this one http://www.zhpmafia.com/forums/showthread.php?16182-Help-with-Suspension-Refresh-at-50k-miles-10-years however probably will skip the front control arms as those were done a while back - but haven't gotten around to it given a very short commute.

I've noticed my car seems to make a knocking noise going over most bumps. A partially depressed manhole cover is a good example of something that would produce a slight knock/thud from the suspension, not the tire itself.

Will this go away post-refresh most likely? Any likely suspects r.e. what's causing the noise?

Thanks

hard to say without driving the car, but normal clunks are caused by:

- a bad ball joint
- a bad swaybar endlink
- a bad strut or shock (depending on if the clunk is in the front or rear)

if you're refreshing enough parts, you'll cure it. ;)

[johnrando]

FCABs can cause a clunking sound too.

[slater]

FCABs can cause a clunking sound too.

generally for me they always generated a slight tug in the steering wheel under light braking, but no noise - i guess they would have to be REALLY bad to make noise. ;) :)

[nsk040]

About how long does it take to put in shocks/struts and all the associated hardware if I were to undertake this project with another member?

Thanks

[BMWCurves]

The first time I did the shocks/struts it took me about two days on my car, but I was taking my time. When I did the same replacement on my sister's car it took me an afternoon. Having an impact wrench sped up the process immensely. Also, be sure to take pictures of the front strut assemblies i.e. the front strut with the strut mount and spring all together before you disassemble it. I made the mistake on my car of assembling the left strut with components for the right side...sort of. But it meant I had to completely disassemble the front strut assembly all over again.

[nsk040]

May also try to do the rear lower control arm which got bent somehow (how does one bend a control arm?) - is this something that could be done along with the suspension refresh or is this better left to an indy shop? If so, how much complexity does it add?

ZHPizza - Appreciate the tools offer, however I'm probably lacking the skills do do this on my one.

704sw (Spenser?) - At this point I'm pretty committed to just doing the full refresh, not just diagnosing the noise. Shoot me a PM if it might make sense to do the refresh in conjunction with each other.

Thanks guys.

[ELCID86]

I had a knock when going over speed bumps, etc. turned out to be the nut on one of the end links/stabilizers.

[BMWCurves]

I had a rattle that was a loose caliper bolt. I also had a sort of "thud" sound when going over minor bumps that I think was effectively just the shocks/struts having no rebound at the first two inches of travel. My sister's 330Xi had an intermittent clunk/rattle in the rear that was a blown rear shock mount.

I think you're taking the best route since you're already refreshing the suspension, you'll most likely eliminate the rattle/clunk in the process (depending on how many components you replace). I'm not sure on how much work it takes to replace the rear lower control arm.

[nsk040]

Found a good shop to do the refresh. 3 questions before I order parts:

-I have been advised to go with Bilstein HDs, but also considering the OEM Bilsteins as the OEM car was great earlier in its life. How much stiffer are the HDs relative to fresh OEMs? Is the real benefit of the HDs that they will last longer?

-After getting the car on a lift, I was advised that the RTABs were totally fine and not worth replacing. What would be the benefit of doing the RTAB replacement now (110k miles)? If I don't do them now, what symptoms may appear in the future that would suggest they are due to be replaced?

-Rear diff bushing...how tough is this install? Sounds like mine is fine for now, but something to keep an eye on...

Thanks

[ZHPizza]

Which shop did you end up at?

And I'll always recommend Koni FSD's for a street car. I just finished putting them in my ZHP if you want to give it a test drive and see what you think (once I get the car put back together).

[nsk040]

PM sent.

[quikryptonite]

I had a knock when going over speed bumps, etc. turned out to be the nut on one of the end links/stabilizers.

This happened to me as well. Just tightened it up and the noise went away.

[nsk040]

I got my car done with Bilstein HDs, Lemforder FSMs, Turner Aluminium RSMs, and reinforcement plates. Totally transformed the car. 98% of the suspension noise (knocking going over bumps) is now gone.

1) There are still a few small knocks (much quieter). I'm guessing probable culprits are FCABs (replaced at ~75k), FCAs (never replaced per recommend of tech who did the FCABs at 75k), tie rod endlinks, or sway bar endlinks? Anything else?

2) Looks like the front is now a little bit higher - i.e. more wheel gap. Is this normal until the car "settles" into the new suspension?

[nsk040]

I did Lemforder FCAs, FCABs, and sway bar endlinks up front. Steering does feel a touch better, but unfortunately there are still a few knocks/taps which come from the front end. Front sway bar bushings looked very solid. I guess I could do new tie rods but would like a little better diagnosis before I spend another few hours under the car.

Any ideas?

[704sw]

Hmm...steering coupler? You've hit the big items other than the tie rods.

I just did FCAs and tie rods (FCABs were still good so I reused them) and it totally transformed the car. I'm doing the steering guibo when I do the oil pan gasket as a "while I'm in there" kind of thing.

[Oli77]

2) Looks like the front is now a little bit higher - i.e. more wheel gap. Is this normal until the car "settles" into the new suspension?

I think the reinforcement plates might be the culprit for this. At least, this is my conclusion. My car also sits a tad higher a year later after redoing my front suspension.

[nsk040]

I think the reinforcement plates might be the culprit for this. At least, this is my conclusion. My car also sits a tad higher a year later after redoing my front suspension.

I think your right about the plates. It has also settled a bit by now so I think it's back to normal.

[nsk040]

Hmm...steering coupler? You've hit the big items other than the tie rods.

I just did FCAs and tie rods (FCABs were still good so I reused them) and it totally transformed the car. I'm doing the steering guibo when I do the oil pan gasket as a "while I'm in there" kind of thing.

My steering feels very good; the issue is just the annoyance of the noise. How long did the tie rods take? I guess each one has 2 potential areas of noise (outside and inside) so crossing off those 4 potential areas of noise may be a good idea. The tech who had my car on a lift though said my tie rods were fine but that was just using his hand to pull and stuff to see if there was movement.

[704sw]

My steering feels very good; the issue is just the annoyance of the noise. How long did the tie rods take? I guess each one has 2 potential areas of noise (outside and inside) so crossing off those 4 potential areas of noise may be a good idea. The tech who had my car on a lift though said my tie rods were fine but that was just using his hand to pull and stuff to see if there was movement.

I had GMP do mine. I couldn't get some of the rusted connections undone, so I just had them do a lot of things in one fell swoop. If you do the entire rod I think they'll say "we have to remove a bunch of shit and charge you a lot," whereas the outer ends are a lot easier to do.

If the outer ball joint "was fine" I wouldn't think the rods are your issue. Absent the clicking from the ball bearings in a bad joint, I can't imagine the ties making any noise (just sloppy steering when they're failing). If I'm wrong, someone please chime in.

[nsk040]

By "outer" I assume you mean this part? https://www.fcpeuro.com/products/bmw-tie-rod-assembly-left-e46-32111096897-1

Or do you mean just the outside half of the linked part?

[Vas]

Personally when doing tie rods, I recommend doing both the inner and outer at the same time ( complete tie rod assembly )

The inner joint does wear out as well and create play But the inner will not make clunking noises. A bad ball joint can make noise though.

[704sw]

By "outer" I assume you mean this part? https://www.fcpeuro.com/products/bmw-tie-rod-assembly-left-e46-32111096897-1

Or do you mean just the outside half of the linked part?

Just the black half of the linked part is the outer tie rod end.


Personally when doing tie rods, I recommend doing both the inner and outer at the same time ( complete tie rod assembly )

The inner joint does wear out as well and create play But the inner will not make clunking noises. A bad ball joint can make noise though.

Bingo. I'll always recommend doing the whole thing, but this is absolutely right. I personally only replaced the outers because it's what finances allowed for at the time. It (among other replaced parts) resolved my sloppy steering, but I obviously know at some point I'll be replacing the inners too.

[nsk040]

I would just do the whole thing as you recommend (i.e. part linked). Never saw just the outer half of the tie rod available for sale so was curious.

[nsk040]

Maybe the noise is coming from the back, and I'm just mistaken in thinking it comes from the front. What would be likely culprits at the back for the subtle knocking/tapping noise (kinda sounds like someone tapping the bottom of a kitchen pan with the soft part of their finger)?

Shocks, shock mounts, and reinforcement plates are brand new at the back. Everything else at the back is original.

[704sw]

I don't know about that specific sound, but there are a lot of wear items in the back:

sway bar end links/bushings, subframe/diff bushings, control arm bushings, RTABs.

[ZHPizza]

Drive with the rear seats down and you'll know if it's coming from the rear. There's very little sound deadening in the trunk area.

[nsk040]

Good call on putting rear seats down. That experiment only gave me more confidence that the noise is coming from the front. Anything left up front besides tie rods and sway bar bushings?

[holyc0w]

Does the noise occur during braking, turning, acceleration, steady speed?

[nsk040]

Does the noise occur during braking, turning, acceleration, steady speed?

I tend to hear the noise (may actually be two distinct noises) driving down rougher paved roads at ~20mph. These roads don't have potholes, probably best described as having been excavated before for sewer or whatever and then repaved...and the repaved spots create indentations or humps. Car is basically static as it goes over this road...i.e. no turn/brake/acceleration.

On a smooth road, I can't reproduce any noise by getting on the brakes hard or aggressive steering inputs. My steering feels like new on on ramps so I'm not thinking tie rods or guibo are the issue.

Are tie rods and sway bar bushings (only 2 things left to replace) good for well beyond the 110k miles I have on the car? As replacing the sway bar end links didn't really seem to accomplish anything I'm hesitant to continue replacing stuff w/o a good reason to.

[nsk040]

At this point the entire suspension is new, yet the noise remains.

I'm thinking the noise is related to a little movement from something heavy. Likely mounts for the transmission or the diff. It could be engine mounts, but there is zero vibration so these are probably fine.

[Sockethead]

Don't rule out motor mounts. You should check them.
Also, I've had the OEM LCAB fail at 40k. So you might want to check them... If I read right, you didn't replace them this time around?
Recheck you swaybar end links for tightness. When you jack up just one side of the car, you are preloading the end link so it will appear to be tight even if it's a little loose.
Check mounting bolts on engine mounts, steering rack and subframe. Little chance they're loose but when hunting down a noise, you need to eliminate

I read through real quick, did you replace your top strut mounts? That could also cause the noise you are describing. Again they will be preloaded by the weight of the suspension when jacked up. Jack up the car so the tire is only a couple of inches off the ground. Use a big pry bar to lift the tire/suspension up and check for play. Even a little bit of play here will make noise because the strut tower will act like an amplifier.
The reinforcement plates are just sheet metal they won't change ride height.

You mentioned one of your rear lower control arms is bent. That usually happens when the car is towed. The tow truck driver puts the J hook there because it's convenient but it ends up bending them because they weren't designed for that kind of load.

Also, did you check the rear diff mount when doing the rear suspension ? They are notorious for failing. Not related to front end noise but probably needs to be addressed

[nsk040]

Thanks - really appreciate all the info. Trying to respond in order.

LCABs are original. RTABs new. Swaybars have been checked w/ no preload. Tie rods new/checked...though perhaps steering rack could have some internal noise?

Need to get car on lift to check subframe, motor, diff, and transmission mounts.

Shocks/struts all new with new mounts and reinforcement plates.

Very slight bend in lower right control arm. Had an alignment last week and they were able to get it to spec. Car has never been towed, so no clue how that got bent but can't see it being related to the any noise.

[Sockethead]

No, I was just mentioning the bent arm as FYI.
If the LCABs are original, I'd start there. They are fluid filled. If there is any brown around that area, the fluid has leaked out... Mine we shot with only 44K original miles on the car... probably replaced them 3 or 4 times since then... I have 143k on the car now.

If the rear diff mount is shot, it will be easy to tell by prying with a pry bar. If it's torn (usually the first thing that happens) you'll have to physically eyeball the rubber while prying...

[nsk040]

The noise is clearly coming from the front so not likely LCABs.

Had a shop get the car in the air. Engine mounts, transmission mounts, diff mounts are all good.

Their only idea was that one of the new struts was somehow misaligned, however this was only a theory as everything looked good from top and bottom (but we didn't actually take the strut out to confirm). I have trouble believing that the struts were not installed/torqued correctly.

Back to square 1.

[Sockethead]

If you installed Koni yellow struts, there is no nub on the shock body to line it up properly in the steering knuckle. It's easy to get it misaligned. I did it myself the first time I installed them.

[nsk040]

I have Bilstein HDs

[Sockethead]

Ok yea I remember now reading that earlier in your thread

[Sockethead]

You left out the original bump stops on the front struts, yes? The Bilsteins have internal bump stops

[nsk040]

Yes, only replaced the rear bump stops.

[Sockethead]

and you checked the front lower control arm bushings very carefully yes? ( leakage and pry bar for excessive movement)
Running out of things to check...

[nsk040]

FCAs and FCABs are new Lemforder parts, replaced this summer. Didn't pry on them though.

Noise could be something like the wiper fluid reservoir or something like that moving around a bit creating a noise that isn't suspension-related.

[Sockethead]

Yep! These type of noises are a bitch to track down for sure

[704sw]

If you installed Koni yellow struts, there is no nub on the shock body to line it up properly in the steering knuckle. It's easy to get it misaligned. I did it myself the first time I installed them.

My Koni Yellows have an alignment nub! Maybe Koni finally got wise?

[Sockethead]

My Koni Yellows have an alignment nub! Maybe Koni finally got wise?
or they forgot to put it on my set lol

[704sw]

or they forgot to put it on my set lol

I would say "maybe it's personal," but usually that goes *against* me, and not *for* me lol.

[nsk040]

Update: 2 shops have told me they suspect it's the top nut in one or both of the front struts. Unfortunately, getting access to this nut and putting everything back together + the alignment is a pretty large bill to test a theory.

[Oli77]

Top nut can be tightened of checked very easily with a strut nut socket. It has an opening so you hold the center of the strut with an Allen wrench and tighten the bolt. Worth purchasing maybe.

[ZHPizza]

Top nut can be tightened of checked very easily with a strut nut socket. It has an opening so you hold the center of the strut with an Allen wrench and tighten the bolt. Worth purchasing maybe.Shawty I got what you want I got what you need

https://i.imgur.com/PHelGny.jpg

Swing by whenever and take it

[nsk040]

Amazing! I'll text you Nate - thank you.

Is there anything else that could be loose in there (i.e. in the top of the struts)? It seems like the shop which came up with the confident "top of the strut" noise diagnosis would have been aware of this very easy way to test their theory without hours of work.

[ZHPizza]

Shawty I got what you want I got what you need

https://i.imgur.com/PHelGny.jpg

Swing by whenever and take itJust realized that it's a simple spark plug socket with the rubber core removed. You may already have one?

https://i.imgur.com/bkc1Ibo.jpg

[danewilson77]

Just realized that it's a simple spark plug socket with the rubber core removed. You may already have one?

https://i.imgur.com/bkc1Ibo.jpgSo it's a 13/16?

Sent from my S8+

[ZHPizza]

So it's a 13/16?

Sent from my S8+Yep. It worked when removing my OE struts, but it was too small for the nut on Nick's Bilsteins.

We ended up throwing a 7/8" socket on a 1/8" impact driver and got it to tighten 1/4 turn without the strut spinning. Hopefully that was enough.

[danewilson77]

Yep. It worked when removing my OE struts, but it was too small for the nut on Nick's Bilsteins.

We ended up throwing a 7/8" socket on a 1/8" impact driver and got it to tighten 1/4 turn without the strut spinning. Hopefully that was enough.Yeah. Mine is 7/8" as well.

Sent from my S8+

[nsk040]

Noise is gone after tightening up the single nut on the top of the strut! As seen in the pictures above, no need to take out the strut to accomplish this in case others are trying to find a similar noise.

Now I just need to figure out the seat squeak noise.

[slater]

Noise is gone after tightening up the single nut on the top of the strut! As seen in the pictures above, no need to take out the strut to accomplish this in case others are trying to find a similar noise.

Now I just need to figure out the seat squeak noise.

excellent - love the easy ones.

now, about the squeak... driver's seat, rear left corner?

[anandoc]

excellent - love the easy ones.

now, about the squeak... driver's seat, rear left corner?

Peter man, help me diagnose a seat squeak as well. It has been driving me crazy for the last few weeks :(

Seems to be coming from the passenger side....I am guessing its the seat...I have banged around with my fist but cannot reproduce it while the car is stationary. Only happens when I am driving over bumpy roads (which we have plenty here in TO).

[slater]

Peter man, help me diagnose a seat squeak as well. It has been driving me crazy for the last few weeks :(

Seems to be coming from the passenger side....I am guessing its the seat...I have banged around with my fist but cannot reproduce it while the car is stationary. Only happens when I am driving over bumpy roads (which we have plenty here in TO).

weird! try flipping the seat up into 'flip forward' mode and see what happens?

my driver's seat in the X3 is squeaking/creaking a bit in the back left corner. if i push on it with my fingers, i can reproduce the sound. just need to take it apart now to figure it out....

[704sw]

just need to take it apart now to figure it out....

I’d expect nothing less lol.

My driver seat is noisy, but it’s from my leather belt rubbing the leather seat.

[slater]

I’d expect nothing less lol.

My driver seat is noisy, but it’s from my leather belt rubbing the leather seat.

ha, yes... well, i am going to be retrofitting lumbar into the X3 seats anyway, so i'll just wait for that.

the leather-on-leather rubbing would drive me nuts! good thing i don't wear leather pants...

[704sw]

good thing i don't wear leather pants...

I guess your 80s hair band days are behind you, huh?

That’s cool about the lumbar in the X3. I drove my old X3 to Harbor Freight yesterday (got a steal of a deal on a new jack), and I’d forgotten how quiet and smooth it is.

[slater]

I guess your 80s hair band days are behind you, huh?

That’s cool about the lumbar in the X3. I drove my old X3 to Harbor Freight yesterday (got a steal of a deal on a new jack), and I’d forgotten how quiet and smooth it is.

yeah... i started playing guitar in '93, so i was past that anyway - went straight for the grunge/death metal look. ;)

was yours a 2007 also? the LCI updates are great. there is some slop that needs to be eradicated in the trans- and diff-mount areas. and some of the interior plastics are kinda cheap, and noisy - but overall i'm pretty pleased with it. lumbar and FSDs will improve it even more. :)

[nsk040]

The seat squeak noise can be produced by pushing myself back into the seat. I hear it going over bumps usually. It sounds like it's coming from inside the seat - I don't think it's rubbing on anything externally.

r.e. seatbelt noise: I was getting some rubbing from the seat belt a few inches up from where it mounts, so basically by my left hip. The belt was rubbing against the plastic base of the seat so I put some clear tape on the plastic which has helped a lot. The belt makes noise when it rubs on plastic, but not smooth packing tape.

[danewilson77]

Finally found the kit I was looking for.

https://www.ecstuning.com/b-schwaben-parts/strut-nut-socket-set-5-piece/003046schkt/https://uploads.tapatalk-cdn.com/20171026/18f9508bbfec846f7453b0abd97d4387.jpg

Sent from my S8+

[slater]

Finally found the kit I was looking for.

https://www.ecstuning.com/b-schwaben-parts/strut-nut-socket-set-5-piece/003046schkt/https://uploads.tapatalk-cdn.com/20171026/18f9508bbfec846f7453b0abd97d4387.jpg

Sent from my S8+

oh, that's for a honda - see it says "CR-V" on it?


:rofl

[704sw]

oh, that's for a honda - see it says "CR-V" on it?


:rofl

It’s even hyphenated correctly [emoji23]

[Sockethead]

Nice addition to the tool collection... one of those tools that you don't use very often but are thankful that you have it when you need it

[slater]

It’s even hyphenated correctly [emoji23]

i know, i wouldn't have bothered otherwise. ;)

[danewilson77]

oh, that's for a honda - see it says "CR-V" on it?


:rofl!

Sent from my S8+

[Boris3]

Just one more note of thanks guys for this site. I had a front end clunk after I did a suspension refresh earlier this summer (Koni yellows front and rear, front control arms, FCABs, strut mounts, reinforcement plates, sway bar end links). It seemed to start a few weeks after the refresh and I figured it was the tie rods which were also shot but I hadn't done. So just replaced them this past week and went and got the car aligned. Still had the clunk on driver's front. Read through this thread and went out and checked the top nut on the strut...and it was loose. Passenger side was tight. Doh!!!

[704sw]

Just one more note of thanks guys for this site. I had a front end clunk after I did a suspension refresh earlier this summer (Koni yellows front and rear, front control arms, FCABs, strut mounts, reinforcement plates, sway bar end links). It seemed to start a few weeks after the refresh and I figured it was the tie rods which were also shot but I hadn't done. So just replaced them this past week and went and got the car aligned. Still had the clunk on driver's front. Read through this thread and went out and checked the top nut on the strut...and it was loose. Passenger side was tight. Doh!!!

My driver side Koni yellow also likes to loosen itself. Blue loctite on just one side lol.

[Boris3]

Thanks for the suggestion, I'll keep an eye on it. Funny that driver's side loosens up. I used the new nuts that came with the struts and tightened them down the same on both sides before installing.