991.2 Carrera S - Vacuum Sound
Discussion
Afternoon,
I was just looking for a little advice.
I just lucky enough to have picked up a 991.2 Carrera S earlier this week. It’s my first Porsche and I am delighted!
However, I am just finding the internal sound slightly strange at higher revs. The best way to describe it is that when accelerating at c.5k rpm plus it sounds like a vacuum has been switched on in the cabin. It’s very sudden and ends up masking the crescendo of the engine / exhaust which in itself sounds fantastic.
The sound ties in with the boost gauge hitting circa 3/4 so I can only imagine it’s the air pressure in the engine being pushed through under high pressure?
Having done a little googling, I don’t know if this sounds like the ‘symposer’ and whether looking to try and plug it would be the answer? I understand there are two in a 991.2?
In terms of spec that could potentially make a difference the car has PDK, sports chrono and sports exhaust and having played around it doesn’t seem to make a difference if the car is in sport or normal or with the sport exhaust on or off.
Has anyone else had similar and if so found a way to improve it? The car is booked in for its 4-year service in a couple of weeks, so I can ask the dealer to look, however I just wanted to see if there was a quick fix?
Thanks all
I was just looking for a little advice.
I just lucky enough to have picked up a 991.2 Carrera S earlier this week. It’s my first Porsche and I am delighted!
However, I am just finding the internal sound slightly strange at higher revs. The best way to describe it is that when accelerating at c.5k rpm plus it sounds like a vacuum has been switched on in the cabin. It’s very sudden and ends up masking the crescendo of the engine / exhaust which in itself sounds fantastic.
The sound ties in with the boost gauge hitting circa 3/4 so I can only imagine it’s the air pressure in the engine being pushed through under high pressure?
Having done a little googling, I don’t know if this sounds like the ‘symposer’ and whether looking to try and plug it would be the answer? I understand there are two in a 991.2?
In terms of spec that could potentially make a difference the car has PDK, sports chrono and sports exhaust and having played around it doesn’t seem to make a difference if the car is in sport or normal or with the sport exhaust on or off.
Has anyone else had similar and if so found a way to improve it? The car is booked in for its 4-year service in a couple of weeks, so I can ask the dealer to look, however I just wanted to see if there was a quick fix?
Thanks all
Mine doesn't make any vacuum noises. You should be just hearing the engine sing, and nothing else.
What max boost pressure are you seeing on the info gauge?
Edit:
Windows up - no vacuum sound at all. Just engine noise and flat-6 sounds.
Windows down at low speed - a bit of turbo whistling as you'd expect. Wind noise with windows down above 40mph masks this out.
Full throttle and high revs means the volume of engine noise masks the turbo noises.
What max boost pressure are you seeing on the info gauge?
Edit:
Windows up - no vacuum sound at all. Just engine noise and flat-6 sounds.
Windows down at low speed - a bit of turbo whistling as you'd expect. Wind noise with windows down above 40mph masks this out.
Full throttle and high revs means the volume of engine noise masks the turbo noises.
Edited by fistenburger on Wednesday 1st July 10:52
It should be on the multi-function display to the right of the tacho on the instrument cluster.
https://www.youtube.com/watch?v=RzWlAcCPLEo
You can configure the display to show various items, so it may need you to tell it to show boost pressure. If you're hearing the vacuum noises in the car it could be a boost leak so worth checking you're showing full boost pressure under load. The display will help with this.
Where abouts are you located? If you're near Bristol I could help more in person.....
https://www.youtube.com/watch?v=RzWlAcCPLEo
You can configure the display to show various items, so it may need you to tell it to show boost pressure. If you're hearing the vacuum noises in the car it could be a boost leak so worth checking you're showing full boost pressure under load. The display will help with this.
Where abouts are you located? If you're near Bristol I could help more in person.....
I found that the symposer had an annoying drone and I ended up blocking it. This is quite easy to do (I used some foam rubber) and can be undone if you don't like the change. The one I blocked was accessed be prising off the rear panel in the cabin. Search Rennlist for more detail. It was a much nicer drive afterwards.
Guys,
Just a quick one to say thanks for your responses. I wanted to wait until I had resolved the problem before replying. In short the car has just been in for its 4 year service, and it looks like one of the pipes were loose.
I am delighted to say I now get the full sound of engine and sports exhaust!
Just a quick one to say thanks for your responses. I wanted to wait until I had resolved the problem before replying. In short the car has just been in for its 4 year service, and it looks like one of the pipes were loose.
I am delighted to say I now get the full sound of engine and sports exhaust!
efb88 said:
Guys,
Just a quick one to say thanks for your responses. I wanted to wait until I had resolved the problem before replying. In short the car has just been in for its 4 year service, and it looks like one of the pipes were loose.
I am delighted to say I now get the full sound of engine and sports exhaust!
I picked up a new to me 2016 991.2 C4S Cab yesterday, it also is whistling at me. I wondered if you know the exact cause of your problem ? Thanks Just a quick one to say thanks for your responses. I wanted to wait until I had resolved the problem before replying. In short the car has just been in for its 4 year service, and it looks like one of the pipes were loose.
I am delighted to say I now get the full sound of engine and sports exhaust!
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