AMG 43 Engine Sound & Gear 'snatch'

[jcx911]

Hi Folks,

I have the GLC43 which sounds absolutely stunning in Sport+ mode with pops and crackles from the exhaust. Problem is, economy is nothing short of horrible in Sport+ mode on short journeys and in town when setting off from a standstill the gears can sometimes 'snatch' and 'kangaroo' when lightly touching the throttle to set off making it look like i dont know how to drive a clutch!

While the gear issue must surely be a thing for the garage to investigate, i wondered if anyone may have had a similar issue?

Also, is there a setting, a cable, etc with which to tamper to get the exhaust sounding throaty in all modes? With the Porsche Sports Exhaust which is switchable you can unplug a cable to leave the flaps open at all times - thus making it sound epic at all times.

inputs appreciated.

Thx

[Webdunk]

I have the GLA45 AMG with switchable exhaust. It's a very different beast to the Cayman R switchable exhaust I used to have.

I think it's got a lot more to do with exhaust temp and engine mode than good old gas flow and valves. So the exhaust will sound different in different engine modes. There's basically no difference with the sports exhaust in Comfort for me for example. And I suspect some of that horrible town economy in S+ will be do do with the software lobbing unburnt fuel down the exhaust.

[jcx911]

Hmmm thx. Your engine in the 45 is different again to the 43 but i get your point that there may be additional factors in play.

As for the economy difference, its more noticable that just the 'lobbed' fuel :-) its almost 40% different on a 10mile round trip in Sport vs Sport+.

somewhere a setting gets changed. if it is communicated via electric to a valve or a flap then it may be 'modifiable' :-)

[Webdunk]

jcx911 said:

somewhere a setting gets changed.

The days of it be 'a' setting are long gone I fear. Driving modes can now affect engine mapping, gearbox mapping, throttle pedal resposne, traction control, ESP, exhaust behaviour, suspension behaviour, stop/start, aircon... the list goes on. Behaviours and how they interact with each other will bear on both your exhaust and economy queries/observations.

[jcx911]

Webdunk said:

jcx911 said:

somewhere a setting gets changed.

The days of it be 'a' setting are long gone I fear. Driving modes can now affect engine mapping, gearbox mapping, throttle pedal resposne, traction control, ESP, exhaust behaviour, suspension behaviour, stop/start, aircon... the list goes on. Behaviours and how they interact with each other will bear on both your exhaust and economy queries/observations.

Progress...i guess. tx

[paulwirral]

I've noticed similar in my 43 slc , it is heavy on fuel in sport plus but I don't use it in town , not really sure why you would but everyone's different .
I've also noticed a slight delay - snatch on the gearbox , I'm assuming you have a variant of the 9 speed ? It's seeming to get more regular too at low speeds though I've not had time to investigate properly so I'm not much use to you but at least you know it's not your imagination .
If you manually release the park brake via the dash it's smoother but still there sometimes .

[jcx911]

paulwirral said:

I've noticed similar in my 43 slc , it is heavy on fuel in sport plus but I don't use it in town , not really sure why you would but everyone's different .

Blush: I like the sound it makes and as pedestrians hear it coming they are safer too :-)

paulwirral said:

I've also noticed a slight delay - snatch on the gearbox , I'm assuming you have a variant of the 9 speed ? It's seeming to get more regular too at low speeds though I've not had time to investigate properly so I'm not much use to you but at least you know it's not your imagination .
If you manually release the park brake via the dash it's smoother but still there sometimes .

Yes a 9sp auto. its less about the brake and more about the clutch i think as the brake is off when it happens.

[paulwirral]

jcx911 said:

paulwirral said:

I've noticed similar in my 43 slc , it is heavy on fuel in sport plus but I don't use it in town , not really sure why you would but everyone's different .

Blush: I like the sound it makes and as pedestrians hear it coming they are safer too :-)

paulwirral said:

I've also noticed a slight delay - snatch on the gearbox , I'm assuming you have a variant of the 9 speed ? It's seeming to get more regular too at low speeds though I've not had time to investigate properly so I'm not much use to you but at least you know it's not your imagination .
If you manually release the park brake via the dash it's smoother but still there sometimes .

Yes a 9sp auto. its less about the brake and more about the clutch i think as the brake is off when it happens.

I don't use it in town as my hair is as white as the car , wife chose it , the more I can do to stop people looking at me when driving it the better .
As I said , I've noticed a similar snatch - lurch occasionally when accelerating gently from a low speed , like the gearbox has somehow been caught out ?
when I have time I'm going back to the dealer to ask about it and an annoying slight rattle seemingly under the steering wheel pad or dash , but this won't be for a couple of weeks yet . I'll keep an eye on here just in case you find out what it is so I can go pre armed !

[jcx911]

paulwirral said:

jcx911 said:

paulwirral said:

I've noticed similar in my 43 slc , it is heavy on fuel in sport plus but I don't use it in town , not really sure why you would but everyone's different .

Blush: I like the sound it makes and as pedestrians hear it coming they are safer too :-)

paulwirral said:

I've also noticed a slight delay - snatch on the gearbox , I'm assuming you have a variant of the 9 speed ? It's seeming to get more regular too at low speeds though I've not had time to investigate properly so I'm not much use to you but at least you know it's not your imagination .
If you manually release the park brake via the dash it's smoother but still there sometimes .

Yes a 9sp auto. its less about the brake and more about the clutch i think as the brake is off when it happens.

I don't use it in town as my hair is as white as the car , wife chose it , the more I can do to stop people looking at me when driving it the better .
As I said , I've noticed a similar snatch - lurch occasionally when accelerating gently from a low speed , like the gearbox has somehow been caught out ?
when I have time I'm going back to the dealer to ask about it and an annoying slight rattle seemingly under the steering wheel pad or dash , but this won't be for a couple of weeks yet . I'll keep an eye on here just in case you find out what it is so I can go pre armed !

I hear you Paul - not exactly incognito. :-).

Yes the gearbox does feel caught out.

And I have rattles too. From dash binnacle, roof near mirror and both front doors... On rough roads it rattles like a cheapo car. I plan to have dealer investigate.