My 210 is almost done, one more thing left to do
 

I think I'm almost done replacing stuff on our 2000 E320 that we bought last October, here's a little recap. I replaced the right cat assy. because the right bank of cylinders would shut down under hard acceleration. Last week I replaced the left cat assy. because #4 cylinder was shutting down under hard acceleration. All is fine now!! The left side was making a racket when idling so I knew they were all broken up inside like the right side was.

Now that my running issues are resolved the one thing I have left is a popping noise coming from the front end. It will pop when I use the brakes if I change directions, another words after they are hot (doesn't do this when the car is cold first thing in the morning), when I come to a stop, nothing. I back into my parking spot.....POP from the front left and right areas. I go forward a couple of feet and can get it to pop again. It only does it if I change directions. If I keep going forward all will be quiet. I'm wondering if the caliper bushings are prone to wearing out on the 210's. It sure sounds like bad caliper bushings to me but before I go ordering some I wanted to throw it out here to see if this is a common failure item on the 210's.

Thanks for the extensive help you all have given me. It was you guys on this forum that lead me to replacing my cats the first time when the right bank of cylinders was shutting down. I'm a grateful individual for this forum!!

Dale

At the risk of a stupid question, are you sure you don't have the infamous "popping seat" issue? Every W210 I've ever been in had it -- including the two my family owns.

Cheers, John

It's definitely coming from the front end John. I've had other cars that needed the caliper bushings replaced and they sounded similiar to what mine does. I did a search on here and couldn't find anyone specifically complaining about this is why I was asking if it was common or not.

Might want to look at the spring perches spot welds..
Do a Search ..

Hi Arthur,

Good to hear from you!!

I looked at those closely a couple of weeks ago when I removed the front rotors to have them turned. It was making the noise prior to this so it's not like I left anything loose. There was no rust or cracks anywhere in the welds so I kind of ruled those out. I couldn't feel any play in the caliper bushings when I removed those but then again what are the chances of me feeling any to begin with unless they were about to fall out. Who knows, I'll probably just order some new ones and give it a try because the front end bushings are all just about pefect. The car doesn't wander, no looseness in the tie rod ends or ball joints. Got to be something simple like the bushings....I hope!!! :)

I wouldn't automatically assume brake problem when noise occurs under braking.

Could be loose balljoints, for example.

Its probably the upper or lower ball joints.


My W126 will give a nice pop when I hit the brakes harder then normal, I am 90% sure its the upper ball joint. Currantly I am ignoring the problem, not high on the to do list.

Another tell tail sign is popping when you back down an apron.

Dale,

Just a thought, try shooting a little bit of WD 40 into the swaybar bushings.
There was a time when my girlfriend popped,.......but only once. :Dl

Silicone spray or grease won't harm the rubber and will last longer. Hit the sway bar links too, they can make a popping noise.

Ahhhh, now there's a possibility I hadn't thought of......Excellent and many thanks!! I'll be digging into this popping noise in depth this weekend and will let you know what it is. I believe you may have hit the nail on the head!!

may as well hit the idler arm bushing, too..

although...that one is usually a squeak, not a pop

Dale,
I would suggest you spray one item at a time.
That way you may know for sure what the culprit is/was. ;)

Might want to have a look at the front lower control arm bushings

I have replaced Several on the W210s for the knocking noise

Will do gents and thanks everyone for the suggestions!!