acr2001

So, at this point my 05 C240 with just under 40,000 miles seems to have a new (expensive) problem every week. I am disgusted and ready to sell the car. I really loved it for a while and I took great care of it, always following all of the maintenance and using OEM parts. I'm going to post a thread soon with the entire list of everything that has broken on this car during its service life.

A week or two ago the transmission was leaking from the common electrical connector failure point.

Yesterday 3 of the 'soft buttons' on the COMAND unit stopped working.

Today, a rear suspension component broke and I am not sure what it is yet as I won't have chance to get under it until tomorrow. Basically every time I hit a bump or dip in the road the rear makes a sprnigy "booiiingoingoing" noise. Kind of like a clown car. The best way I can describe the noise is the type of sound you get when you "flick" a large spring - like the ones on your garage door.
Anyone care to guess?

fookoo303

broken spring. I've heard of it happening to a couple other 4matics

C280AF

I share your frustration, I would be interested in what you find out because I have this same noise and have for quite some time now. I just recently had my rotors swapped and new brake pads put on (im sure its completely not realted but coiencidently) and now I have a "rattle" noise on both sides of the front end when I hit a bump as well. I am taking it in on Friday to have those noises looked at and I have heard and read that trying to keep track of the suspension/steering noises on our cars is almost never ending. Let me know what you find out and Ill share my outcome as well of my "rattle" noise.

fookoo303

For you, it could be bad sway bar end links

C280AF

Yea I have read it could be a multitude of things from bushings, to arms, to bars and I wish I had time to get under the car to fix it myself but unfortunatley I am planning a weeding out of state.

The more I read the common sensus does direct the attention of the noise to the spring. It might be covered under your warranty (if you have one) where your mileage is so low though so might be worth checking into.

Glyn M Ruck

+1 do you have any salt corrosion on your springs?

acr2001

I just had a look under there (without lifting the car) and I can't really tell whats going on. Springs to my surprise look good. Hopefully I'll get a picture later when it's on the lift. Something major has to be broken because this is a very loud "Woah what just happened? Did I run something over?" noise. I'm afraid to drive it any further than to the shop.

acr2001

I finally got the car back from my mechanic. He was unable to find anything wrong with it nor was he able to duplicate the sounds / vibration!!!

I took the car home and it is completely gone. This is very disconcerting to me because this was quite a loud heavy "spring-like" sound coming from the back of the car. Enough that me and my passengers thought it unsafe to drive.

I drove the car around today and tried to stress it. I did hear the noise one more time (but MUCH less loudly) when I deliberately hit a speed bump at high speed. The noise is now completely gone and the car is handling fine.

Any ideas? I'm worried this is going to come back and bit me on a road trip that I have planned. Is it possible that a spring in the rear is lose and came out of its alignment only to be forced back into the proper alignment before my mechanic saw it?

Silver C

Well best bet is to disassemble your spring setup and reassemble it just to make sure..

Glyn M Ruck

Things don't fix themselves unless something was flung up from the road & lodged somewhere & is now gone. I would examine springs very carefully.

Carsy

Rear shock mountings loose or broken & rubbing against springs?

acr2001

This is what my mechanic and I thought. But I did get the noise one last time today like I said when hitting that speed bump, and there is no way anything is still lodged in there. He had it up on the lift. I'm infuriated that after such a huge issue it is suddenly gone, but on the other hand I haven't had to dump any more money into the car for once. On our old E class the hub broke, causing the wheel to nearly fall off, so you can imagine how confident I am....

I'm going to crawl under there again tomorrow but everything looks fine. The springs look good, no rust. One of the shocks DOES have some paint missing and a line of rust where it faces the wheel - as if it had been rubbing against the inner wheel. It's been there since I purchased the car and it is old rust - so it is not currently an issue as far as I can tell.

acr2001

My mechanic said that one of the shocks was "slightly loose" and that he tightened it, but that it shouldn't have made any difference.

OneOfaKindTrini

Is your car financed bro?

samaritrey

When my dad and i did my rear shocks we did not tighten them down enough. I drove it about 15 minutes to my aunts house and it made the worst noise ever like the rear end was about to fall off so it could have been that. I was scared to drive the car that is how bad it was lol. That said i would take the rear springs out to check them if you have a floor jack and the proper wrenches it takes like an hour max to take both off and check them out.

acr2001

It is, but nearly paid off and it's worth more than I owe.
I'm more than likely going to sell it in the next few months. It's just such a gigantic piece of garbage - I cringe when I get in it because I know something new is going to break or the AC is going to emit an unimaginably foul odor.

Why do you ask?

Glyn M Ruck

Have you done the evapourator sanitise?

acr2001

Yes, it lasted for almost 2 months and stinks again. Only masked the problem.
I've sprayed so much disinfectant in over the years that I'm surprised the blower motor isn't rusted out yet.

OneOfaKindTrini

I was going to tell you cut your losses and trade it in bro. I say it all the time, but I did notice all the trouble you are getting with it. Avoid repairs and save your money toward a down payment.. Most dealers don't even look at the car when you go to trade it.

mskembo

Reading your post, I have to share one with you. I had a similar issue on my 528i, loud noise from the rear that I was sure was suspension related. Took it to my mechanic (45 min away) and noticed half way there that it wasn't doing it anymore. Long story short, I had a set of 30lb dumbbells in my trunk, and they were making the noise. Once I cleaned my car out (as I do any time I take a car into the shop), the noise magically disappeared. I felt like an idiot when I figured it out.

mleskovar

My guess is broken spring....like several other people have guessed. Putting it up on the lift extended the springs and they "snapped" back into place and because the springs are aligned they look OK. Lift the rear wheels off the ground and use a piece of wood between the spring coils to force them apart to see if there is any separation crack.