Aging C300

My 2010 C300 Sport just started CREAKING like an old mattress spring when I go over a bump or come to a stop. The creaking during stopping happens when the car lurches to a stop and rebounds slightly -- a little creak with each motion. I do not hear or feel anything weird when applying the brakes in general, neither squeaking nor creaking. When I push down on each corner of the vehicle I do not hear any creaking or squeaking. I cannot pinpoint where under the car the sound is coming from. Any thoughts would be much appreciated.

TimC300

Jack up the car and remove the wheels. try and wiggle everything under there checking for anything loose. Its best to jack up the car from the front middle jacking point so both wheels are hanging and pressure is taken off the sway bar. I go overboard with the jack stands and huge blocks of wood, im paranoid about the car falling. Grab a pry bar and try to move the control arms around.

Creaking could be a strut or bushing. Bushings could just be aged and dry. Its really the banging sounds you need to watch for. Last winter I had a really loud creak on the passenger side i thought I was in for a big repair, then spring came and it warmed up and totally went away.

I like to spray PB Blaster silicone lube on the bushings, ball joints, and sway bar bushings. I feel it at least softens them up a little. No oil or petroleum lube which can eat away at rubber.

cvx5832

Your profile doesn't say, but it this a Rust Belt car? If so, or anywhere like it, I'd get the subframe inspected. Especially since it was a sudden onset.

Aging C300

Thanks for your response. It's a So Cal car and I just had the front sway bar links replaced 6 months ago. It does seem to creak most when I'm braking into a bumpy curve, and it does seem to be coming from the front end. We did have a ton of rain (!) recently and I was forced to drive through some flooded intersections, maybe that has something to do with it...? I'm not a do-it-yourselfer, so I'm going to the mechanic soon and will update.

Aging C300

My new mechanic said a front sway bar link was broken so replaced both and no longer hears the alarming creaking while braking on bumps or into curves, however he still heard a little squeaking and said that could be struts but was not a safety concern, they are in good shape. I didn't hear anything when I pushed the car up and down at each corner. He did say there was a slight squeak or creak (we have to listen together and agree on the proper term) when turning the steering wheel hard right or left but said the control arms and bushings look okay if I can live with a little squeak or creak. He lubricated bushings and ball joints as you suggested. There was a massive rain recently and I was driving through flooded intersections and he said that could be part of the problem. Thanks again for your response!

TimC300

6 month old sway bar link broken again? I wonder what brand was installed. My car had Mercedes sway bar links in and they were bad, they made a clunking over bumps and the boots were torn so im assuming water got in a washed the grease out making them wear faster. I was cheap and bought a chinese set off Amazon and those didnt even last one day. I then bought Febi Bilstein from FCP for the life time replacement. They are the first thing I check when I have the wheels off.

I was recently hearing a banging noise over bumps. Turns out a screw was missing that secures the plastic undertray and it was flopping around.

There is a bearing in the struts that can squeak or wear. It allows the spring and shock to rotate separate from the upper mount.

California

Check for rear subframe corrosion, this is a recall as of February 2023

Aging C300

Looks like it was the control arm bushings. Since there’s 132,000 miles I took recommendation to replace front left and right control arms. Struts were deemed okay.