Common problems with the W205 AMG C63
It has got me pretty scared as my car has recently ran out of warranty. We will see what is what very soon.
I have been at the dealer for them to check it out, and they said it is a common sound with this engine. Because of pumps and hardware installed in that part of the car.
I have also asked a friend with a GLC63S to record me a video from the left front corner of his car and it makes literally the same sound.
I doubt two new cars would be broken in the same way at the same time.
With that said, my concerns are mostly gone. When i will see another 63s i will listen to it to ensure it makes the same sound aswell.
His car ran out of warranty like a half a year ago. It has around 100 000km on the clock and after diagnosis it was discovered that the 6th piston in the engine has lost all compression. Which means the engine is probably dead. It was completely stock.
We will see what is up after further teardown of the engine. Either way, i wanted to share this, as it is one of the first failures of this engine that i heard of.
His car ran out of warranty like a half a year ago. It has around 100 000km on the clock and after diagnosis it was discovered that the 6th piston in the engine has lost all compression. Which means the engine is probably dead. It was completely stock.
We will see what is up after further teardown of the engine. Either way, i wanted to share this, as it is one of the first failures of this engine that i heard of.
It seems to have gotten a bit better, but it can still occasionally be downright lurchy starting from standstill, reminiscent of a new driver who doesn't know how to use a clutch. It's annoying -- even embarrassing -- when it happens. Can anyone confirm that this goes away over time?
Coolant was low once, seemed odd, but I topped it up.
Went dead after stop start once. Never knew why!
Back end stepped out when I wasn't expecting it, I'm very wary on a wet road now. TC saved me, was quite a fright though and I wasn't hammering it.
I put car seat covers, decent ones with a Merc logo, it's saved my seats from the kids!
My dogs will lose their minds when they ride in a convertible for the first time.

Hit race mode on a dual carriage way, decided to knock it down in gears at the roundabout and it went in neutral! I don't use it much like this so was a bit of a surprise. Are there false neutrals in the box!
Been quite enjoying working out the lights in the fog though, you can actively see it working.
The Best of Mercedes & AMG
1. Sometimes the horizontal yellow volume indicator simply doesn't show up, and there is no way to put any volume on the system at all - applies to CarPlay, regular radio, phone, etc.
2. CarPlay is buggy, and sometimes hangs, doesn't launch right, etc. Seems to work better if the car is started THEN the iPhone is plugged in via USB
Has anyone else had these issues? I'm hoping there is a software update....




1. Sometimes the horizontal yellow volume indicator simply doesn't show up, and there is no way to put any volume on the system at all - applies to CarPlay, regular radio, phone, etc.
2. CarPlay is buggy, and sometimes hangs, doesn't launch right, etc. Seems to work better if the car is started THEN the iPhone is plugged in via USB
Has anyone else had these issues? I'm hoping there is a software update....
1. Sometimes the horizontal yellow volume indicator simply doesn't show up, and there is no way to put any volume on the system at all - applies to CarPlay, regular radio, phone, etc.
2. CarPlay is buggy, and sometimes hangs, doesn't launch right, etc. Seems to work better if the car is started THEN the iPhone is plugged in via USB
Has anyone else had these issues? I'm hoping there is a software update....
Last edited by FLC63s; Mar 29, 2021 at 09:00 AM.

For this reason, I tend to park the car with the auto handbrake OFF after washing. It is parked in my home garage, which is perfectly level, so no chance of it rolling and even if there was, I guess the Park gear would prevent this.
I have a Seat Belt Cover on the driver seat fading and chipping away! Looks terrible. 1st thing you see when you get into the car.
Exhaust pipe outer trim is also fading and chipping! Looks ****!
Wiper are a nightmare in the wet! (Anyone have any luck with hood wipers?)
Squeek from the door trim just under the glass. Elbow in the window sort of thing.

The leak was caused by one of the lower hoses on the drivers side rubbing against the engine block. Mercedes have revised the part in an attempt to stop the hose failing, so they obviously know about the issue, but haven't been proactive in recalling vehicles, probably because it isn't safety related. So, be warned, this could happen to your C63S!
Here's my list of issues:
1. Coolant hose poorly designed and will eventually fail.
2. Random warning "Intelligent Light System inoperative", which usually clears the next time I use the car.
3. Starter battery critical warnings. This happens from time to time when the car is stored in my garage (it isn't driven every day), but always happens when I clean the interior of the car, requiring the doors to be open and interior lights on for 20 minutes or so. Never had such poor battery usage on any other car!
4. VERY squeaky brakes. Tried everything to resolve, even the main dealers (under warranty), but to no avail.
5. Windscreen wipers seem to be very flimsy compared to other cars I've owned.
5. Wind noise from door windows when travelling at higher speeds.
6. Occasional rattle from the dashboard, which I've been unable to locate or even determine why/when it happens.
7. Like others, I see debris collecting inside the front bumper but can usually get it out with a vacuum and a little effort, so not too much of a problem.
The leak was caused by one of the lower hoses on the drivers side rubbing against the engine block. Mercedes have revised the part in an attempt to stop the hose failing, so they obviously know about the issue, but haven't been proactive in recalling vehicles, probably because it isn't safety related. So, be warned, this could happen to your C63S!
Here's my list of issues:
1. Coolant hose poorly designed and will eventually fail.
2. Random warning "Intelligent Light System inoperative", which usually clears the next time I use the car.
3. Starter battery critical warnings. This happens from time to time when the car is stored in my garage (it isn't driven every day), but always happens when I clean the interior of the car, requiring the doors to be open and interior lights on for 20 minutes or so. Never had such poor battery usage on any other car!
4. VERY squeaky brakes. Tried everything to resolve, even the main dealers (under warranty), but to no avail.
5. Windscreen wipers seem to be very flimsy compared to other cars I've owned.
5. Wind noise from door windows when travelling at higher speeds.
6. Occasional rattle from the dashboard, which I've been unable to locate or even determine why/when it happens.
7. Like others, I see debris collecting inside the front bumper but can usually get it out with a vacuum and a little effort, so not too much of a problem.
The leak was caused by one of the lower hoses on the drivers side rubbing against the engine block. Mercedes have revised the part in an attempt to stop the hose failing, so they obviously know about the issue, but haven't been proactive in recalling vehicles, probably because it isn't safety related. So, be warned, this could happen to your C63S!
Here's my list of issues:
1. Coolant hose poorly designed and will eventually fail.
2. Random warning "Intelligent Light System inoperative", which usually clears the next time I use the car.
3. Starter battery critical warnings. This happens from time to time when the car is stored in my garage (it isn't driven every day), but always happens when I clean the interior of the car, requiring the doors to be open and interior lights on for 20 minutes or so. Never had such poor battery usage on any other car!
4. VERY squeaky brakes. Tried everything to resolve, even the main dealers (under warranty), but to no avail.
5. Windscreen wipers seem to be very flimsy compared to other cars I've owned.
5. Wind noise from door windows when travelling at higher speeds.
6. Occasional rattle from the dashboard, which I've been unable to locate or even determine why/when it happens.
7. Like others, I see debris collecting inside the front bumper but can usually get it out with a vacuum and a little effort, so not too much of a problem.
As for your #3, last month my on board Dash displayed Check Battery see owner manual. Until then my iphone would most times would show Battery partical charge. So l I drove it to MB Dealership and it was determined the battery was not ok. So to my surprise they replaced the battery under warranty even though it has over 22, 000 miles and over 3 1/2 years old. The job took about 2 1/2 hours.
. As per # 6, Yesterday I got my car back for a passenger side rattle. They applied Krytox Lub
e to the interior and exterior roof seals, allowed lubricant to settle in place and test drive with foreman corrected this rattle. I drove home yesterday and the rattle was gone for now.
Last edited by jj18; Jan 7, 2023 at 02:33 PM.
1.) squeaks and rattles from dash, overhead console, and rear headliner area.
2.) rear shocks replaced at 14k miles for leaking.
3.) Electronic Thermostat replaced under warranty @ 18k miles
4.)Active brake assist inoperative message at 20k software update performed under warranty.
5.) brake squeaking @ low speeds
Still love this car more and more each day.

When I first noticed the coolant leak, using a torch to attempt to find the issue, I did notice there was more coolant pooling at the left (looking at the car from the front - drivers side) on top of the plastic cover under the car, when looking down through the engine bay, so it fits in with what I could see.
While the affected hose has been re-designed by Mercedes to include a protective sleeve, or a sleeve that stops the hose loosing its shape (I'm not sure of exactly the intention), I don't see any posts from C63S W205 owners reporting this issue (apart from me)! Maybe I was just unlucky, but even so, I'm still pretty annoyed by it!
Last edited by milleniumaire; Jan 8, 2023 at 10:23 AM.

As for your #3, last month my on board Dash displayed Check Battery see owner manual. Until then my iphone would most times would show Battery partical charge. So l I drove it to MB Dealership and it was determined the battery was not ok. So to my surprise they replaced the battery under warranty even though it has over 22, 000 miles and over 3 1/2 years old. The job took about 2 1/2 hours.
. As per # 6, Yesterday I got my car back for a passenger side rattle. They applied Krytox Lube to the interior and exterior roof seals, allowed lubricant to settle in place and test drive with foreman corrected this rattle. I drove home yesterday and the rattle was gone for now.
Prior to my 2019 C63S W205 I owned a Jaguar XKR and never had such issues from the Jaguar dealers, even after the warranty expired. They only ever charged me for the work that needed to be done. It's possible this was because I bought the car from them, but I'm not impressed at all by the Mercedes dealer network near to me and can't bring myself to trust them, when the first thing they ask for when booking the car in, is for a £80+VAT payment to perform "troubleshooting"!




The leak was caused by one of the lower hoses on the drivers side rubbing against the engine block. Mercedes have revised the part in an attempt to stop the hose failing, so they obviously know about the issue, but haven't been proactive in recalling vehicles, probably because it isn't safety related. So, be warned, this could happen to your C63S!

there was a slight smell the following day when I opened the bonnet (hood) to top it up and could see coolant on the floor under the car.







