abhargava99

Hello. I am new to this forum and would greatly appreciate any help and insight that you can give me. I have a 2018 GLS 450 that has done around 17000 miles- bought it when it had done 13000 miles. Since I had it- there is a rattle upon acceleration when the turbo starts spooling. I have taken it to two different dealerships- the latest thought is that this is a rod in the left waste gate that is rattling when the waste gate is in the open position. Mercedes Benz says that since this is not affecting the operation of the car or performance, there is nothing to be done about this. They tried a software update that did not work. I am wondering if anyone else had this issue and if there is any solution? it is very disappointing to hear such a sound in the cabin while driving- you do not expect this in a GLS. There seems to also be a loud hiss from the turbo when in sport mode.

I would be grateful for any thoughts on what I can do.

thank you

BlownV8

Go to a different dealership. Their response it total BS. I would also make a call to MB and let them know.

Jt0230

Go to another dealership, and also call MBUSA. The answer they gave you is wrong. The SUV is under warranty and they can do something about it. If this was me, I would first look through any maintenance records (and/or carfax) to see if previous owner brought up the same issues. If you know what dealership the previous owner brought it to get serviced, I would try to talk to them to see if they can give you any more information. Another thing you can try is taking it to a private shop and see if they can find anything. Hope this helps.

PC11214

Good day everyone!
I bought a CPO 2017 GLS with 9000 miles on it couple months ago, I found the same noise issue with it! I took it back to MB dealership where I bought but unfortunately they gave me the same answer! So disappointed!

drauch86

Did anyone ever get this resolved? The dealer did a software update on mine that Mercedes said would turn the rattle into a hiss, and now it does both.

Nico Cialis

To this day, I encounter the same annoying sound when the tachometer on my 2016 GLE COUPE reaches 1500 RPM and the rattle continues until 2000 RPM. It will briefly resurface while transitioning between higher gears, but it's not as noticeable at higher speeds.

That said, I had taken the vehicle into MB of Austin to have it serviced for another more significant reason and they repaired that issue with the CV JOINT along with a few other damaged parts that I wasn't aware of, so I was very thankful for their exceptional service.

HOWEVER, the service center explained to me upon pick-up that the mechanic's notes depict no detectable rattle noises were present during servicing/test drive after I told them I wanted the mechanic to please listen for a subtle rattle sound when approaching 35 MPH when they test drive it, because that is the 2nd reason why I brought it in.

Petmerctech

There is a bulletin addressing this issue. It involves a software update that modifies the actuation of the turbocharger wastegate. I'm sure your dealer has performed this and it changed nothing, which is what I experienced. The rattle is from the wastegate, which is integrated with the turbocharger on the 276.821 motor. The solution for the noise is to replace the turbocharger. The bulletin states that the noise is normal and the turbocharger must not be replaced but this is not completely true. With more persuasion, ie. speaking with the shop foreman or service manager and expressing your dissatisfaction, the turbocharger can be replaced. A good dealer would not even return the vehicle to the customer in this state and would take the initiative and contact MB to authorize replacement of the turbocharger.

p5657587

I actually went from a 2015 GL450 to a 2017 GLS550 just to get away from this rattle. The bulletin did make the rattle appear higher up in the rev band, but never made it go away. Turbo swap didn't change anything either.

I also have a E450 right now with the same engine and it also rattles. I gave up.

cjaredscott

I have a C450, and I have the same issue (same M276 biturbo engine). It's rather annoying. I'm going to be bringing it up the next time the car goes in.

Petmerctech

I'm guessing it's a hit or miss whether a turbocharger in this engine makes a rattle or not and you were unlucky to get a replacement turbocharger that also rattles. That's probably why MB states to not replace the turbocharger in the bulletin and that the noise is deemed normal and acceptable and is not considered a mechanical defect.

audian

Hey Guys,

I bought an used 2020 GLS 450 with 5600 miles on it and notice the same rattling noise while accelerating. The sound almost seems like the GLS trying to mimic sports car engine in the most crudest way possible.
Did any of you have found a solution to this issue?

a79st

hello I have a 2018 Mercedes E400 and it is not having the same noise during acceleration , it is currently at the dealership now but its been a few days and I have not been updated. My car only has 22k miles on the dash. Were you able to get the issue resolved ?

mbkroik

Did anybody mange to get it fixed? I bought 2018 GLS 450 CPO recently and figured this was an issue. I brought it back to service but they said the noise was normal (sic! how this can be normal?) Called MBUSA but they claim noise is normal. Am I paranoid? How is it possible this hasn't blown up yet? You buy $80k car and you hear annoying rattle noise every time you accelerate and nobody cares?