Jack the front up and spin the tires by hand, maybe debris got caught up in there, maybe the brake pads broke or bolts are coming loose, maybe the lug bolts are loose, maybe your tires have a defect or flatspot.

 

Don't forget to look and see if an old baseball card is caught there.

Buellwinkle is probably right. Check anything that's speed sensitive. The only thing that is speed sensitive and not engine sensitive are wheels, tires, powertrain. And speedometer.

 

rock caught in the tire tread?

 

Thanks for all the ideas, but it is fairly consistent in that it only does it after driving for maybe a half hour. Doesn't do it until then...

 

After half an hour of driving? Possibly sounds to me like a wheel bearing. The wheel bearings are packed with grease - obviously! But, what happens is, when the wheel is cold, the grease is tacky/sticky. As the hub warms up, the grease thins out, dries up a bit, and the bearing has a tendency to wear a little. Over time, the bearing simply makes noise. As a simple check, when it makes noise - and on a relatively dead street - swerve left and right. If it is indeed a wheel bearing, you should be able to tell which side it is on.

 

How would swerving left and right help me determine which side it is on?

 

Okay, so usually after driving for 1/2 hour, I start to hear this noise coming from the front end (or within the dash -- it's hard to tell!). It sounds like when you put a card in the spokes of your bicycle -- remember that?

Anyway, it is speed related. Speeds up, slows down as in relation to my mph. Is NOT engine speed related. It's not really loud, but loud enough to be noticeable and annoying.

Any ideas? Wheel bearing? Axle? Normal noise?

Try checking your insulation in the drive shaft tunnel. Mine was making the same noise. At the rear of the driveshaft, the insulation is fastened in the center but not on the sides (you'll see what I mean when you look at it.) The sides curled down and starting rubbing on the driveshaft making a click-click sound. I trimmed the two sides that were rubbing and no more noise. You'll have to remove the heat shield to get to it. Hope this helps.

 

A world of THANKS to you! 15 years after you posted this, your suggestion got a grandma (travelling alone) out of the middle of nowhere without stroking out from the worry of making things worse.
Who would've guessed?

 

How would swerving left and right help me determine which side it is on?

When you swerve from side to side, it puts more load on the one wheel bearing and less on the other. So, lets say it is the right front wheel bearing. As you turn to the right, the load is alleviated from the right and placed on the left, reducing the amount of noise from the right. When you turn to the left, the load is placed on the right wheel bearing, causing it to make more noise. Same goes for the rear.

 

Try checking your insulation in the drive shaft tunnel. Mine was making the same noise. At the rear of the driveshaft, the insulation is fastened in the center but not on the sides (you'll see what I mean when you look at it.) The sides curled down and starting rubbing on the driveshaft making a click-click sound. I trimmed the two sides that were rubbing and no more noise. You'll have to remove the heat shield to get to it. Hope this helps.

Hey...This is NO JOKE. I found mine was indeed BENT when I went to install my Remus setup. I would suggest it highly likely that C320_User is correct. The fact that metal EXPANDS when it gets hot even supports the theory. SIMPLE to check! Use jackstands, and NOT just a jack, okay? -Good luck!

 

it might be the center support bearing --mine is making the same noise but i have not wanted to go up underneath and replace it----It is not the rear end either because i know what that sounds like!

 

Maybe Its Insulation under the driveshaft tunnel...

Check this Thread

http://www.benzworld.org/forums/w203-c-class/1191074-ticking.html

 

What's a center support bearing?

 

I do not think the C-Class has a support bearing due to the short driveshaft. Otherwise, the support bearing usually holds the front half of the driveshaft.

 

Well Whosdis, since you seem like a decent human being, and since for some reason everyone else simply guessed at the answer to your question rather than providing you with anything even remotely helpful, I will answer you:

The problem lies with either Component M2/10 or M2/11, the Left Footwell Flap Actuator or Right Footwell Flap Actuator, respectively. One of those components is Stiff or Blocked, which causes the clacking sound periodically. It will cost you a few hunski to get it fixed because it requires getting behind some of the dash components.

It's not at all a serious problem, you ought to just wait and have it fixed next time you get your oil changed. Good luck with that, and to all of you who provided no help to this poor guy, shame on you.

 

Eureka! That's it! Makes perfect sense because it started after they removed my dash to replace the A/C evaporator. Thanks!

 

But wait, on second thought and upon further reflection...

How could it be a flap actuator if it seems to speed up when I speed up and slow down when I slow down. And I turned off the fan last time it happened, but continued making the noise.

Does that diagnosis still make sense?

 

It is a ROTATIONAL noise, which has nothing to do with the flaps, any good mechanic will know this---especially when it has to do with speed of the noise as the car gets faster-- turning the drive shaft, hanging of insulation etc----shame on who???

As for the center support, all w203 cars have a 2 part drive shaft and have a support bearing in the middle of the car--I have had this apart to check on another of my sportcoupes-----just like the old w126 cars when you hit the gas it causes a thumping noise in the middle of the car if bad--- but if seperated or bearings are shot will cause the rotational noise ----especially if you get on it all the time

I think landsharks problem could be the insulation but like i said before have not gotten up underneath the car to troublshoot my rotational noise any further---

 

I have had the same issue for months. I'm so glad you posted this thread. I'm going to see if I can get it on a lift and take some pictures this weekend if my buddy can fit me in.

 

Shame on you, HeirKranz, did I not make that clear in my post? You needed clarification?

I will wager my car on the fact that it is the footwell flap actuator. Take it to the dealer, and if I'm wrong I will give you my car. If I'm right, HeirKranz and the rest of you should trade your cars in for Honda Civics and stop shaming us real Benz owners.

Center support beam my ass... but I have another question, what good is it recieving all these inexperienced guesses as to what the problem is? A message board reply won't fix your problem, and if you dont have the ability yourself to diagnose the problem, then you most likely won't have the ability to fix the problem and will have to take it to a shop anyway...

 

Okay... well, you are right Jerk, in your assumption that I don't have the ability to fix the problem myself. BUT, I'd really like to have a good idea of what the problem is so I can tell my service advisor. When I first mentioned it, I was told to bring it in when it was making the noise -- not really practical since I'm usually no where near the dealer when it starts.

I have checked the undercarriage for the insulation theory, but I do not see anything that would be remotely close to touching the drive shaft so I thing that possibility has been ruled out.

After reading your suggestion, it certainly does sound like it is coming from the dash...

 

And the winner is:

C320_User!

Noise positively identified as: Insulation hitting the driveshaft.

 

Shame on you, HeirKranz, did I not make that clear in my post? You needed clarification?

I will wager my car on the fact that it is the footwell flap actuator. Take it to the dealer, and if I'm wrong I will give you my car. If I'm right, HeirKranz and the rest of you should trade your cars in for Honda Civics and stop shaming us real Benz owners.

Center support beam my ass... but I have another question, what good is it recieving all these inexperienced guesses as to what the problem is? A message board reply won't fix your problem, and if you dont have the ability yourself to diagnose the problem, then you most likely won't have the ability to fix the problem and will have to take it to a shop anyway...

24posts+no information+no vehicle information+ramblings about cars he knows nothing about =jerk for real

here is some homework for you jerk--post a picture of the footwell flap actuator and show us all how this component can lead to this noise

....yes and i have not taken my car to the dealership since the warantee was up----140,000 miles so far with my mechanical abilities noob!

 

HeirKranz are you actually bragging that you're just a mechanic? How's poverty working out for you?

 

My apologies, I said I would check it out over the weekend and post some pictures, but wedding planning took over and I didn't get to it. Do you have any pictures?

 

Yo, Jerk! Obviously the government is paying you to live because it is painfully obvious you can't get a job with your IQ of less than 1. The original post states the ticking speeds up as the vehicle speeds up. A flap actuator tick will not speed up, unless the gear is wearing out, but then it is still not vehicle-speed related.
Also, I will be glad to drive to your place and pick up your car whenever you're ready. "I will wager my car on the fact that it is the footwell flap actuator. Take it to the dealer, and if I'm wrong I will give you my car..." (quoted from post #20). PM me and I will definitely give you my phone number. You can even call me collect! And, I am a cylinder head rebuilder. If I can afford a Mercedes-Benz doing what I do, then anyone should. And if you are doing something other that stacking building blocks for some government social worker - and evidently smarter than one of us mechanics - than you should be driving an SLR McLaren or something more expensive tha a mere C-class!