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Engine vibration on acceleration.

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Old Aug 19, 2022 | 11:12 PM
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Default Engine vibration on acceleration.

In normal mode brief vibration occurs when the engine is warm at low acceleration rpms. Also in sport mode but at much higher rpms.
Engine mounts have been checked.
2022 Cab with 5,500 miles. Have experienced since the car was new.
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Old Aug 20, 2022 | 08:02 AM
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Have you ridden in another 992? Another 911? Where are you feeling or hearing the vibration?
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Old Aug 20, 2022 | 09:08 AM
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Vibration seems to originate from the middle of the engine compartment. It is not constant, but frequent when in Normal mode, and occassionaly at higher RPMs when in Sport mode. One service manager suggested it might be the pressurized fuel pump.

I have not ridden in another 992.

I have a service appointment soon, so any suggestions are welcome.

Thanks for your interest.
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Old Aug 20, 2022 | 09:20 AM
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Since you have a cab, does it matter if it is top up or down? Could be issue with the top?

Did the SM think it is abnormal? If so, they can just replace the fuel pump and see what happens.

Any difference if you change suspension setting?

Just trying to figure out how being in sport mode makes this happen at higher rpm.

Is is rpm dependent or road speed dependent?
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Old Aug 20, 2022 | 09:34 AM
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Convertibletop position has no impact.
SM did not suggest replacing the fuel pump, just mentioned it as a possibility ( he had recently relocated and I assume had experienced the fuel pump issue at his previous dealership.I assume internal discussions ruled that it was not the fuel pump, although thay offered no solution other than checking the engine mounts.
I would guess the vibration is rpm dependent.

My upcoming appointment is with the Atlanta dealership which sold me the car. The sm i am referring to is with my home dealership in Louisville.
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Old Aug 20, 2022 | 10:25 AM
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Originally Posted by earldorsey
Convertibletop position has no impact.
SM did not suggest replacing the fuel pump, just mentioned it as a possibility ( he had recently relocated and I assume had experienced the fuel pump issue at his previous dealership.I assume internal discussions ruled that it was not the fuel pump, although thay offered no solution other than checking the engine mounts.
I would guess the vibration is rpm dependent.

My upcoming appointment is with the Atlanta dealership which sold me the car. The sm i am referring to is with my home dealership in Louisville.
Louisville dealer is Bluegrass Motorsport?

If so - I’ve had dealings with their service department…You’re doing the right thing in getting another opinion. Hopefully ATL can help.
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Old Aug 20, 2022 | 10:30 AM
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On second thought, putting the car in sport mode will have the car at higher rpm at the same road speed.

Are you 100% sure this is rpm dependent?

Can you replicate at different gears?

I am not sure how they can check if the dynamic engine mounts are functioning properly.
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Old Aug 20, 2022 | 04:23 PM
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Fuel pumps on the end of the camshafts in my 992 chirp like a house of blue ****, I just accept they do this but it’s bloody annoying. Happens around 1k to 1.5k rpm.
Noises higher up the rev range I can’t hear, I just hear engine, turbo, exhaust and waste gate.

It’s worth trying to really work out exactly what rpms it happens at, on/off/part throttle, try and record the noise if you can.
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Old Aug 20, 2022 | 04:56 PM
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I checked while driving this morning, the vibration ocurred in the 1200/1500 rpm range in normal mode. A deep rumbling vibration sound.
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Old Aug 20, 2022 | 05:26 PM
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Is this a base C2 cab? I have driven a 992 base C2 cab and a Targa 4S. The base C2 had a lot more noise in the cabin at low rpms, including what might be described as vibration. The sound of that vibration also changes with the dynamic engine mount damping between modes I believe.

To be honest I thought the vibration noise was actually appealing and fits to the car's character. A 911 is not a quiet car and I even like the throaty sound of the base engine over the T4S (although my wife prefers the T4S because it is quieter in the cabin).

Our T4S doesn't have as much of this vibration noise, not sure if it's a model difference or if there was some issue with the prior base C2 cab...
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Old Aug 20, 2022 | 06:23 PM
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Originally Posted by earldorsey
I checked while driving this morning, the vibration ocurred in the 1200/1500 rpm range in normal mode. A deep rumbling vibration sound.
There is a well documented sound on this forum at approx 1500 RPM in a lot of our cars. My 2020 C2S has had it since the day I took delivery. Regardless of road speed the engine sounds like it is lugging (and it might be). Frankly - after not getting anywhere with the dealer, I gave up and just avoid those RPMs (Sport Mode/Manual Shifting for around town to the rescue).

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Old Aug 20, 2022 | 09:52 PM
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Originally Posted by mferris
There is a well documented sound on this forum at approx 1500 RPM in a lot of our cars. My 2020 C2S has had it since the day I took delivery. Regardless of road speed the engine sounds like it is lugging (and it might be). Frankly - after not getting anywhere with the dealer, I gave up and just avoid those RPMs (Sport Mode/Manual Shifting for around town to the rescue).
Mine makes what sounds like a dull metallic sounding resonance noise around 1800 when accelerating pretty slow in auto mode (possible lugging). SA said it’s normal but still weird as it really feels like going through a resonance around 1800 when slowly increasing RPM. It’s not fuel pump, mounts or exhaust (my exhaust is gone). I got used to it and simply avoid slow acceleration ;-) where I can.
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Old Aug 21, 2022 | 07:54 AM
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Originally Posted by Tobeit
Mine makes what sounds like a dull metallic sounding resonance noise around 1800 when accelerating pretty slow in auto mode (possible lugging). SA said it’s normal but still weird as it really feels like going through a resonance around 1800 when slowly increasing RPM. It’s not fuel pump, mounts or exhaust (my exhaust is gone). I got used to it and simply avoid slow acceleration ;-) where I can.
My symptoms exactly, even the rpm range. Interestingly, the reputation of German engineering precision requires there be a definitive explanation for the vibration and its function. After your post, I am less concerned, but I intend to explore the reasons during my September service sppointment.
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Old Aug 31, 2022 | 06:54 PM
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Today, dealer’s service rep immediately diagnosed engine mounts as the source, within 1 minute driving at 15 mph. It is not widespread, but an issue. Replacement mounts, used on GT3 models, were ordered.

Will advise if interested.
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Old Aug 31, 2022 | 06:59 PM
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Originally Posted by earldorsey
Today, dealer’s service rep immediately diagnosed engine mounts as the source, within 1 minute driving at 15 mph. It is not widespread, but an issue. Replacement mounts, used on GT3 models, were ordered.

Will advise if interested.
Mhm, I wish you had a good audio as your and my description seem to be similar yet my SA states "normal".
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