ZappaF15E

I have a 2014 E550, only 25000 miles. A chirp noise has started in the left front. At low speed, NO braking, and mainly when turning left, I will get a fairly loud chirp noise. Just one and then a few seconds later another chirp noise. Thought it was brakes at first but it is doing it without braking. it is not a belt. Thanks for any help.

Buffalo MB

I had this issue, but disappeared after my dealer performed a recall service, I believe it was a suspension recall.

Not sure if they were related, but seemed like it went away after that service and never heard it again.

CaliBenzDriver

My '14-E350 started doing the same at 10kMi, dealer could never reproduce complaints...
I bet it's the left LINK or BUSHING of stabiliser bar or perhaps a BALL JOINT if it has seen repeated curb abuse.

BALL JOINTS tend to sing non-stop ...
while
LINKS mostly get noisy under compression going over speed bumps or bouncing side to side for cornering hard.

Additionally there's a TSB regarding replacement of a single bad strut within a VIN range... I am not a fan of one-side only suspensions work so I skipped.

After getting the STEERING RACK RECALL plus an extra alignement (out of pocket) my E' stopped tracking straight... so I simply opted to disregard the old car noise: no problemo!

ZappaF15E

Thanks for the replies. Here is a video

CaliBenzDriver

lucky it's simple stuff!

For some reason your brake calipers sound like they are not releasing fully.

I'd recommend lubricating the slider pins with an improved lubricant based on SILICON... not petroleum!! See pic below:
​​​​​

SILARAMIC: high temp brake silicon lube is the best I know 👍

My brakes got hard to stop at only 10kMi... so I took them apart to find the OEM lubricant had already evaporated under heat. I lubed my pins and chamfered contact surfaces. My brake pedal became velvety responsive with feather touch!

That was my early wake up call on "the best car..." lip service.... ✌️

Don't wait too long to fix that... else your rotors will get warped from extreme heat generated while the pads are busy coating your rims. For a pad upgrade path consider getting "AKEBONO PRO": the best for daily driving.

ZappaF15E

i'll give it a try thx

ZappaF15E

i lubed them up real good. still squeaking. just like the video only does it after the car has been driven for about 10 to 20 min. And only around 5-10 mph

bmwpowere36m3

In the video it looks like your rolling forward slowly and applying the brake. Is that accurate?

Were looking at the rear wheel, correct?

ZappaF15E

yes.

CaliBenzDriver

... rear pistons are not moving effortlessly.
Since you have them well lubricated already, then either you have an air bubble in the line or rusted bores chewing the square piston seals.

Flush the system with fresh fluid, bleed the rears, swap calipers, swap the pads in the order you see fit.

Use non OEM Akebono pads as they seem to lay down dark carbon as a form of anti-noise friction modifier.

At any rate your brakes are going to be amazingly responsive 👍

BTW: Title says Left FRONT... how did it move to the rear???

bmwpowere36m3

Sounds like typical brake squeal... which can be due to specific pad (brand), lack of proper lubrication of sliding surfaces or need for bed-in. Sometimes specific pads just squeal and replacing them solves the issue. One thing to check is the sliding surfaces for the pad ears on the caliper bracket are free of rust, pads move easily in/out and the metal-to-metal contact surfaces are lubricated. Also lubrication of pad backs that contact caliper and piston.

If that and performing a bed-in don't resolve the squeal... replace the pads (rotors if needed as well).