johnand

Ok, so I posted a few months ago that I was getting a rocking motion when coming to a stop. I am at 76K miles. Now I am getting a popping or knocking sound just as a come to a moderate or hard stop (like pop-pop). I also get the popping of knocking to a lesser extent when accelerating from a stop (same pop-pop). I also have had a popping coming from the steering when turning the wheel coming off my driveway with the suspension flexed/bound (This produces a similar pop but is not just pop-pop, it pops many times, how many pops depends on how far I turn the wheel). I have a very steep driveway, so when coming off of it and turning, one wheel is compressed, the other is extended, putting bind on the swaybar, so I am thinking swaybar endlinks, or strut thrust bearings/bushings. What do you guys think? Would either of those cause the rocking motion as well?

I was under the car this weekend, and the torque strut and cross strut bushings look perfect/new. So, it appears the new torque strut bushings are so far, more robust than the old ones. The rack bushings look perfect as well since the rack in new and only has a little over 25K on it.

TruTaing

Does it not make the sound during basic driving over rough roads?

Glyn M Ruck

Damn John. I would be highly suspicious of the sway endlinks. Not sure this would cause rocking though. popping yes. If the castor bushes look OK they probably are OK. My new ones are thusfar wearing well compared with the originals even though they were the same part number. MBSA said they had been improved under the same number & I did not believe them. Maybe I will have to take back my words

I would also check the main sway bushes.

You have a new rack - are you sure that the rack bolts are tight? Also - when they replaced the rack did they install 4 new rack mount bushes/rubbers. Presume these are what you are saying look good?

Is this pop pop more of a creak or groan or the sort of noise you would expect if something was worn & had play in it? Some carefull application of rubber grease will stop creaks & groans.

johnand

No solid and smooth when driving over rough roads at speed.

johnand

Definitely more of a worn out/play thing and not creak and groan. Yes, when they replaced the rack, the new rack came with new bushings, and yes, those are the bushings I checked that look good. Have not checked rack bolt torque. Will start with that. Then will disconnect the swaybar endlinks and drive the car and see if that changes anything. Main swaybar bushings look good, but do squeak a little on occasion. If the rack, and endlinks are good, I will check the strut bearings mounts, by disconnecting at the top and checking them by rotating and looking for rough or play.

TruTaing

If the end links are worn or lose, they would make noises over rough roads, not just coming to a stop. I believe you can rule that out.

seagel1000

I have the similar issues. When letting my car stand for a few hours. Basically here is my issue:

After a few hours of having the car parked, say I'm reversing out of a drive way or parking spot, as soon as i apply the brakes to be able to shift to D, it makes a knocking-popping sound twice one after another. Then, after that noise, when I come to a stop it does it again twice. After that, the noise goes away until the next time I settle my car for a few hours. Doesn't happen over bumps or any rough roads. Just when applying brakes on a reverse or take off from having the car sit somewhere for a while. I saw the thread that TruTaing made about common suspension noises. I ordered sway bar end links and replaced them last week. Issue is still occurring for me.

Any other ideas?

My vehicle is a 2005 C230 Sport Sedan

johnand

Sounds almost exactly like my issue. Mine only does it when cold sitting like overnight, then goes away after a short drive too. I think between you and John (TruTaing) we have ruled out swaybar endlinks. Does yours make popping noises while turning the wheel?

Took a very mechanically inclined coworker for a drive at lunch. He said it is the exact noise his 3 series made when the strut bearing crapped out. I turned the wheel side to side, and he said I definitely had play in the strut mounts up top. Going to drop the top of the strut down this weekend and turn the strut mounts and see how the bearings are acting. He said on his, he could barely turn the mount by hand.

LILBENZ230

I look forward to hearing what the cause is. My car makes no noises during stopping or acceleration, nor does it "rock" but..

If the car is at a standstill or slow roll (i.e. out of my driveway, backing out of spots, etc) and I turn the wheel back and forth it goes pop-pop-pop-pop-pop-pop-pop-pop. Can feel it slightly in the wheel. Other than the noise there are no symptoms at all. It's done it since ~70,000 miles and is at 89,000 and change now. I'm not too concerned with it. Tire wear is fine, alignment is fine, no vibrations or such. But I would like to remedy it at some point.

johnand

I bolded exactly what mine does and has done for the last 10-15K or so.

LILBENZ230

Weird, though, that I get no rocking or popping when stopping or accelerating and you do. Maybe our cars both have the same thing wrong, but you also have another problem? I can tell you that it's just a nuisance in my experience. It isn't affecting the car at all in any other ways. I'm interested in fixing it, though, because it's just annoying.

Another thing.. mine does it sometimes, doesn't do it at other times but it has nothing to do with temps or when the car was driven for mine. It might not do it when I back out of the garage in the morning, but may do it after I've driven 100 miles and it's hot, or vice versa. There's not a pattern for me.

FrankW

sounds like the sway-bar bushing/bracket is loose. common for the front as well as rear. it causes a semi-loud popping noise.

seagel1000

Mine goes away after just stopping once in Reverse and once in Drive. After that, no noises until the car settles. But yes, night time it seems to come out more frequently (versus day time, the car doesn't have to sit in as long for the popping to occur again). Mines doesn't do it when turning the wheel, only in the R & D instances of stopping. Nothing else.. Well nothing else, for now hopefully lol

Chris

seagel1000

I took my sway bar off when I replaced my sway bar end links. When I removed the bushings and brackets to hold the sway bar, the nuts were tight. I tightened them even more when I put it back on after sway bar links were replaced.

FrankW

the 203 top mount is suppose to rotate when you turn the steering wheel. BMW's doesn't.

Glyn M Ruck

Are you sure this is not brake pads settling one way - then the other in the calipers?

Glyn M Ruck

John - It could be strut bearings - they do get noisy when buggered - but your mileage is low for that problem????? How often do you drive on poor roads?

Don't write off sway related problems just yet. Sway links & bushes can do what you are experiencing in the early stages of failure. They are under tension most of the time & need to get bad to rattle on rough road surfaces.

Glyn M Ruck

John - remember that you & I are hyper critical & sensitive to changes in a vehicle that others might overlook. As a result we catch wear components before they clonk in a suspension.

seagel1000

The noise is definitely coming from the front, engine bay area. For example yesterday after a golf game, I had parked rear in first. It did the noise after a immediate stop sign. 25-30 minutes into driving, i pulled into a parking lot to grab a bite. I had to reverse. When i stopped on the reverse, it made the popping sound again. After that, no noises were made for the night since I "covered" the D & R short stops.

Last time I replaced my fronts was about 7-8 months ago. My rears need changing. This popping issue has been occurring for about half a year.

OneOfaKindTrini

.. John 76k miles? On a 07? Wow man, and I used to a pop when de-accelerating to a stop. From the rear tho.

johnand

Thanks for all the suggestion guys. I will start with the swaybar stuff and rack bolts this weekend. I got my transmission parts to, so it looks like a weekend of wrenching. I'll let you know what I find.

Velociabstract

I agree on the sway bar. Mine was making a popping noise after I did some work on the front end. (swapping springs without a spring compressor) I was winging it without instructions and I left one side of the sway bar connected and disconnected the other. When I got it all back together (didn't want to go easy) whalla! Pop pop pop. The solution was have the alignment shop loosen and re-torque with weight on the wheels. I was tired of fooling with it.

Les

johnand

Crap, my laptop is dead and left the power cable at work and my DVD is dead on my home PC. Anyone have the torque specs for the steering rack bolts, and the swaybar bits?

mleskovar

I agree with Glyn on this one, I had the same problem. Solved it with new pad retaining clips in the front. Couldn't find just the clips anywhere so had to buy a new set of cheap pads to get them

W203E35

Off Topic

Love you sig Matt