Tom D

Hey guys,
longtime lurker, first time poster. I have a really annoying issue that has surfaced very recently with my w204. It is a 2008 C230 4Matic. It has 260,000 kms on it (I am the original owner) and it is starting to show its age with parts failing and etc. I took it to a shop for a squealing sound similar to the one found in this video:

The shop noticed the alternator was on its last legs as well as the tensioners and other pulleys (they were shot). All of them were replaced. However, the sound remains...
I took the accessory belt off and drove around and the sound remains as well, so not pulley related. It is tied to wheel speed.

Essentially, it is a loud squeaking/chirping upon some acceleration (very light throttle) and seems to go away on hard acceleration. It is also sometimes present on deceleration.

The shop will be looking at it again next Tuesday, but if it is something simpler to fix, then I would prefer to do it myself and save some cash.

Does anyone have any ideas? Please let me know!

JettaRed

iTrader: (1)

Please identify your car more completely--year, model, etc.

JettaRed

iTrader: (1)

Have you checked for a bird's nest under the hood?

Tom D

It is a 2008 W204 C-Class C230. 4 Matic. I am worried it is the front driveshaft. While the part is cheap, the job is an absolute pain to do.

Unfortunately, nothing to be found

TimC300

RWD or 4matic? Im guessing RWD. I can hear the chirping which does sound to be replaced to wheel rotation, but it can be coming from anywhere really, front, back, drive shaft? Can you pin point it to a specific location or side of the car? When I was hearing a loud grinding noise I had someone drive my car slowly while I walked beside it and was able to figure out it was coming from the rear drivers side which turned out to be an issue with the parking brake assembly.

Tom D

Hi Tim,
It is a 4matic. Definitely closer to the front area of the car, not the rear. It is hard to tell if it from drivers or passenger side. If I would guess it is passenger.

MB-W204

Did you find out what the noise is? I have the same noise coming from the front as well. Took it to a shop and they said they couldn’t hear anything smh.

Tom D

I posted this yesterday...

TimC300

If you have a floor jack I would jack up the front from the middle jacking point so both wheels are off the ground then spin one of the wheels, the opposite wheel should spin the opposite way. Listen for any noises like rubbing, keep your hand on the wheel and see if you can feel any resistance at any point the wheel is spinning. If nothing then take the wheels off and inspect the cv axle boots for rips or leaking grease. Inspect the brake pads while the wheels are off, maybe get some brake cleaner and clean them up. May have debris on or around the pads. I'm always cleaning the brake pads when I have the wheels off especially the brake dust that builds up on the metal clips where the pads slide on. Inspect the rotors to see if they are wearing even.

antboii

@tomd - hey, listened to the video posted along with your post. To me that sounds like the u-joint in your front drive shaft is shot for the 4matic.

that is a similar sound I’ve hear with working on 4x4 trucks. The u-joints fail and the axles start to create a rattle/squeak/clunking noise from slopping around.

I would put your car on ramps or jack it up and inspect the front drive shaft and u-joints for play. Grab a hold of it and see if it moves around/wiggles/twists as it should not do that.


keep us updated

ant


p.s - also do what @TimC300 said while it’s jacked up. A proper inspection is needed

Tom D

I was worried about it being that. I had to replace the front driveshaft years ago and it was an absolute pain to do. No idea why MB designed the replacement of that component to require to jack up the transmission.

jimyj

I've run into similar issues with the W204, and your concern about the front driveshaft is valid. Squeaking or chirping noises that correlate with wheel speed often point to worn CV joints or damaged boots, which can allow debris in and grease out, leading to increased friction and noise. Another potential cause could be a bent or unbalanced driveshaft, especially given the high mileage on your C230. Additionally, worn suspension components like control arm bushings or strut mounts can place extra stress on the driveshaft, exacerbating any existing issues. It's also worth checking the driveshaft mounts for any signs of wear or damage, as faulty mounts can cause misalignment and noise during driving.
Considering the labor-intensive nature of replacing the front driveshaft, it might be a good idea to have a thorough inspection done by a trusted mechanic before diving into the job yourself. While the part may be inexpensive, the complexity of the replacement can be a real pain—literally! If you're up for the challenge, ensure you have the right tools and maybe enlist a buddy to help. Sometimes, investing a bit more time and effort upfront can save you from headaches down the road.

Tom D

I will be dropping it off on Tuesday at the shop. If they diagnose it, I will rent a hoist and do it myself (I've done it once before but over 6 years ago and at about 130,000 kms. I've heard that salty roads are the death for these cars, and unfortunately up here in Ontario, Canada, they love their salt in winter.

Tom D

Just an update,
It seems to be somehow related to throttle. I assume if it was the driveshaft, I would hear it constantly when at speed. But I can somehow "turn it on or off" depending on throttle.
Any ideas?
I am having it looked over tomorrow by a mechanic (the original one I went to is busy, contrary to myself having an appointment), and was looking for some ideas before I get there to help diagnose this.

RobertR728

Try and take off your oil fill cap on the engine Andy see if the squeak goes away. If it does go away then look up the pcv system for your engine as they are common issues with the vent system. Sounds very much like a squeaky belt and you will notice allot of vacuum on the oil fill hole because the vent diaphragm is torn letting engine vacuum into your engine crank case.

Tom D

I'll give this a try today!