W203 C230 Front end clunk under braking

1993-Present: C200 CDI, C220 CDI, C270 CDI, C180, C200 Kompressor, C230 Kompressor, C220, C230, C280, C300 C350, CGI & CDI BlueEfficiency variants
Post Reply
axeman74
B Class
Posts: 22
Joined: Wed 02 Mar, 2016 10:58 pm
Model you own: w124

W203 C230 Front end clunk under braking

Post by axeman74 » Tue 13 Aug, 2019 11:52 pm

Hi all,

I have a 2006 C230 V6 wagon that has a very annoying clunk from the front end that is being a bit of a bitch to diagnose.

Only happens under braking. Going over speedhumps, rough roads etc is fine, no noise. Just when braking. It is a very loud metallic sounding clunk. Sounds like it is coming from both sides of the car.

I have had the car up in the air three times, checked every single ball joint, bush, inner and outer tie rod end etc, and all are tight. Have tried with suspension loaded and unloaded, again can't find any faulty suspension parts. The car had a roadworthy a couple of months back and the RWC couldn't find any loosness in any of the joints and it passed easily.

Have checked all nuts and bolts for tightness, both on suspension and brakes, and still can't find the cause. In fact I have done every test under the sun to brakes/suspension and still come up with nada.

I am going to change the sway bar bushes and droplinks to start with as the parts are cheap (relatively), but just in case has anyone here had the same issue and did you find the cause? Any common issues with the W203 front end that could be causing these symptoms? Again, it is only hapenning under braking, and is loud enough to be quite noticeable and annoying.

Thanks for any help.

Axeman74

User avatar
John Green
OZBENZ Admin
Posts: 6789
Joined: Mon 20 Jun, 2005 3:49 am
Model you own: w112
Region: Australian Capital Territory
Location: Canberra-center of the known universe
Contact:

Re: W203 C230 Front end clunk under braking

Post by John Green » Thu 15 Aug, 2019 12:49 pm

Loose brake calliper?
M.B Spares & Service 14-16 Lyell St, Fyshwick ACT. Ph 02 6239 1099

http://mbspares.com.au - Supporting Australia's Mercedes-Benz Enthusiasts.

axeman74
B Class
Posts: 22
Joined: Wed 02 Mar, 2016 10:58 pm
Model you own: w124

Re: W203 C230 Front end clunk under braking

Post by axeman74 » Fri 16 Aug, 2019 12:38 am

Thanks John, have checked all the caliper bolts and retensioned to factory specs, all tight. Have a feeling I am missing something obvious. Going under for another round on the weekend.

Axeman74

User avatar
Bartman4800
300 SLR
Posts: 2118
Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: W203 C230 Front end clunk under braking

Post by Bartman4800 » Fri 16 Aug, 2019 11:49 am

Maybe a bit too far fetched, but there should be spring clips around the brake pads.
If those are missing, the pads are loose and can knock.

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

Ivanerrol
Mercedes Demigod
Posts: 5967
Joined: Sat 12 May, 2007 2:21 pm
Model you own: w204
Location: Melbourne

Re: W203 C230 Front end clunk under braking

Post by Ivanerrol » Fri 16 Aug, 2019 1:19 pm

The early W204’s had a series of faulty top strut mounts.
If they were found during warranty they were replaced - if not you pay yourself.
I suspect the last years of the W203 had the same parts.
Also, the struts themselves were known to have issues.

My W204 clunks as well as having an annoying rattling sound from the top strut mounts on uneven roads.
I’m putting up with this until I have a few more K’s up before changing the complete front end stunts out.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

axeman74
B Class
Posts: 22
Joined: Wed 02 Mar, 2016 10:58 pm
Model you own: w124

Re: W203 C230 Front end clunk under braking

Post by axeman74 » Sat 17 Aug, 2019 3:23 pm

Thanks for all the replies and ideas.

I had another look this morning, and lo and behold I think I found the culprit. The L/H caster bush is quite soft and making a clear knocking noise when I lever it from the top with my pry bar. I had previously been testing it from underneath and clearly was not attacking it from the right angle to see and hear all the slop in the bush. The R/H side also has some slop but not as bad as the L/H side which would explain why most of the knocking was coming from that side. I think I have this licked now.

The funny thing is the bush looks perfectly fine, no leaks or cracking, which is why neither I or my RWC mechanic really gave it much attention. Only an extra long pry bar and levering from the right direction exposed it as the annoying knocker.

Just goes to show, look at the obvious and common faults first. Apparently these are a common issue on W203's. Might also use it as ana opportunity to replace some other tired bush's and joints.

Thanks again.

Axeman74

merc-304
Adenauer
Posts: 337
Joined: Sat 09 Jul, 2016 2:55 pm
Model you own: w126
Location: North Coast NSW

Re: W203 C230 Front end clunk under braking

Post by merc-304 » Sat 17 Aug, 2019 3:30 pm

Pelican Parts have a gd tutorial for bush replacement for W203
380 SEC

axeman74
B Class
Posts: 22
Joined: Wed 02 Mar, 2016 10:58 pm
Model you own: w124

Re: W203 C230 Front end clunk under braking

Post by axeman74 » Mon 19 Aug, 2019 6:28 pm

Yep Pelican Parts is good with stuff like that. Just need to decide if I will just replace the bush's or the whole arms. Ball joint still feels tight. Might be a good excuse to buy the factory style bush pressing tool.

Anyone found better quality bush's for this job than the OE lemforder ones? Saw in another groups Febi bush's being mentioned but my recent experience with Febi parts has been mixed at best.

Axeman74
merc-304 wrote:
Sat 17 Aug, 2019 3:30 pm
Pelican Parts have a gd tutorial for bush replacement for W203

merc-304
Adenauer
Posts: 337
Joined: Sat 09 Jul, 2016 2:55 pm
Model you own: w126
Location: North Coast NSW

Re: W203 C230 Front end clunk under braking

Post by merc-304 » Mon 19 Aug, 2019 6:57 pm

Nolathane are avail but a lot more $$
380 SEC

Post Reply

Return to “W202-w205 C-Class Sedan, Estate & Coupe”