from the front of the car that sounds sort of like an owl hooting sometimes when releasing the throttle? I assume it's the waste gate opening or closing. It's just a little annoying.

I'm wondering if that is a normal sound and if not, might it be fixed under factory warranty?

I'm a sound guy by trade and noises drive me bonkers.

 

Ha ha yes yes yes get used to the noises. There are active vents in the grill that open and close. I also feel the transmission makes some noises like your saying as well. MY car does the same things.

 

That's not normal. Did you buy used? If so, the previous owner may have installed blow off vavles.

 

Yes used. Are blow off valves located where I could see them without taking anything apart?

 

Someone can correct me if I'm wrong, but they should be where I have circled in the first picture. That picture is of the stock engine, so the bov would sit in between the two parts, that separate where the line is drawn in the second picture, and you can see what the bov looks like installed in the third pic. Ignore the actual location of the parts in relation to the engine in the third pic, as that is the E63 engine bay, from this install video:


Stock engine:




Stock parts, where the bov would be installed:




Bov(in red) installed in between those 2 parts (on a different MB engine):

 

thanks very much! The sound my car is making is not a hissing sound like that. I'll try to make a recording of the sound. And I've sent a message to the original owner to see if he installed anything like that. Very useful information, thanks again.

 

Hi Saudio,

since my car got a tune, i've the owl noise too. I thought it might be a pressure release from the turbos?
Hope we get some more information about this.

Best
Andreas

 

An exerpt from a review here

No other car sounds so much like there’s an owl trapped under the bonnet when you back off the accelerator – a slight but distinct hoo-hoo (or possibly even woohoo! as it seems to be having a good time) that never ceased making us smile. You don’t get so much of this in the regular model, which probably tells you where AMG found those extra horses.

link is here http://www.carmagazine.co.uk/car-rev...r-2017-review/

 

I've driven them all (minus a Pro), stock and heavily modified, and never heard an owl sound. Wish we had a sound clip, as I'm genuinely curious as to what this sound is that folks are experiencing.

 

It sounds just like a owl lol. Like I said it sounds like active sound dampers opening and closing on the front grill but I could be wrong. My car has done it since new and it is not some big loud noise just a faint owl hoot sound.

 

I'll be damned. So it's normal. Thanks for posting that, I can live with it if it's not an anomaly.

Orc, I'll try to capture the sound for you and post it.

 

We are part of the owl club Andreas. On my car I had the sound before the tune, after the tune it was amplified 5 times. It happens almost every time I release the throttle now, including a new sound like a loud short whistle for an instant right at the release point. Almost like the tires screeching for a half second.

 

Specific thanks to Orcblog and Skilly for really solid and useful information on this forum. I hope to be able to contribute in kind.

 

Both my 2016 GTS and my 2018 GTC Roadster had the owl sound. I have been told by the dealer that it is nothing to worry about

 

I have a stock GTC and i get this sound. EXACTLY like an owl!

 

My engine is a Cavalier fan?

(Is that too obscure?)

 

I just went to youtube and looked up owl sounds lol.

 

So if a dealer can confirm that they do it and it's normal, I wonder if we can track down exactly where the sound is coming from. Because, honestly, I could do without it.

 

I get it. I'm 40 miles from Cville. ;-)

 

Checking in - mine also makes the same soft "hoo" or "woohoo" sound when letting off throttle after a minor level of boost has built.