Loss of boost after 4500rpm
Thread Starter
Newbie
Joined: Dec 2020
Posts: 8
Likes: 0
From: Istanbul Turkey
C63s Coupe, AMG GT R and 458 Italia
Loss of boost after 4500rpm
I have been facing this problem and have taken the car to the biggest Mercedes Service in Turkey 3 times but still got no result. No error seems to appear when they plug it into the computer. Is anyone familiar with this issue? The car has got just under 6000km done with the engine run in period done as advised.
Super Member
Joined: Dec 2019
Posts: 551
Likes: 133
From: Miami, Florida
W205 C63 AMG Coupe
It seems you may be in a soft limp mode. The average code scanner will not detect a soft limp mode code and you would need to take it somewhere that has dealership level diagnostics (I believe the system is Xentry). See if the shop you took your car to has that capability.
MBWorld Fanatic!
Joined: Sep 2016
Posts: 1,723
Likes: 613
From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Exhaust flaps
Definitely sounds like soft limp mode due to exhaust flaps being stuck or the flap motor malfunctioning. First step is to grease all of them with WD40 or a bit of copper grease.
It's an annoying issue which I still face from time to time simply because I still want to retain the ability to use quiet mode.
Going to look at upgrading to an Akrapovic setup some day if I can find one for a decent price.
It's an annoying issue which I still face from time to time simply because I still want to retain the ability to use quiet mode.
Going to look at upgrading to an Akrapovic setup some day if I can find one for a decent price.
