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Discussion Starter #1
Hi,

have had ny 2020 Cayman S since end of July. At first the car rattled on uneven surfaces and at many different rpms. After having the car at the dealer the rattles are now only showing up at 1800 rpm. My problem is that this is my daily for city driving which means I want to use the normal mode on the sport chrono. Unfortunately the PDK strives for keeping the car at 1800 rpms in normal as much as possible which makes the remaining rattles super annoying every single day.

Is this what one can expect from a car with this price tag? In that case, call me severely disappointed in the build quality, it behaves more like a kit car that some hill billy screwed together in a barn.

Any suggestions on what to do or should I just return this piece of crap to the dealer?

No, it's not the passenger seat belt!
 

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I think you might get a little more help if you can give a little more information. Where is the rattle, what does it sound like, any guesses where you think it might be coming from. Is it purely in the 1800 RPM range as you pass through it or does it only come through when the car has been at 1800 RPM's for a while.

The easy fix (said half joking) is not to be at 1800 RPM's I tend to drive manual and sports mode all the time and so I am almost never in the sub 2000 RPM range. But seriously - give us a little more information and perhaps we can help
 

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Discussion Starter #3
The rattle comes from the front, back and right side of the car. The PDK lugs the engine in normal mode every so often at 1800 rpm. But any other mode is mostly unsuitable for city driving since the accelerator gets too sensitive. I’ve thought of setting up the individual mode with pdk in sport and the accelerator in normal which would minimize the 1800 rpm rattles. However, this doesn’t solve the real problem, it’s just a band-aid.
 

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Rattles front, back, and right sounds like a warranty claim to me. It's certainly not normal.
On the other hand it could be something small like a stone somewhere that echoes around. More investigation and treatment required.
 

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Discussion Starter #6
Yes, they fixed the rattles at other rpms for free of course. They will try for free with this as well but I seriously doubt they can considering the severity of vibrations coming from the engine and transmissision at 1800 rpm. They have already indicated that this will be hard to fix. Which is just another way of saying that this is how the car is supposed to be by design. I guess this amount of build quality was enough for the interior with a silky six cylinder engine, but with a four pot at 2500 cc it’s a completely different story.

Any sane human being would downshift at 1800 rpms considering the vibrations coming from the engine, but the pdk stays there for far too long, probably to save a minuscule amount of fuel in some test cycle...
 

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Learn to use the gas pedal in the Sport Mode. When we bought the car, I was using the Normal mode and my wife commented that I don't drive smoothly anymore. I switched to the Sport Mode and in a couple of days I returned to my smooth driving ways. Haven't used the Normal Mode intentionally since then... You just have to apply the gas pedal judiciously...
 

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From new?
Yes :(
It states in the manual it can "clonk" when opening and closing.
But what happens is either side movement or i could be tighten.
Search the forum for valve rattle and you will find more info

edit
 

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Discussion Starter #12
Ok, thx for the tips regarding the soundaktor and the pse valve. I doubt that any of those two are the cause of my problems but I’ll forward them to my dealer anyhow when handing over the car to them for a second attempt.

Sounds like my only real option left is to program the individual mode as normal but with pdk in sport to avoid the 1800 rpm range as much as possible.
 

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This could be a long shot, but have you considered that this may be a faulty engine/gearbox mount?
From what I could understand you have Sport Chrono package and thus dynamic mounts.

Just a guess.
 

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Ok, thx for the tips regarding the soundaktor and the pse valve. I doubt that any of those two are the cause of my problems but I’ll forward them to my dealer anyhow when handing over the car to them for a second attempt.

Sounds like my only real option left is to program the individual mode as normal but with pdk in sport to avoid the 1800 rpm range as much as possible.
Pse valve is easy to check :)
It is the open/close movement that can cause alot o rattle.
So have Pse inactive and if the sound is still there then you prob can rule out the valve.
 

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Discussion Starter #15
Pse valve is easy to check :)
It is the open/close movement that can cause alot o rattle.
So have Pse inactive and if the sound is still there then you prob can rule out the valve.
Then I can rule it out immediately since this concerns only sport Chrono in normal mode...
 

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Discussion Starter #16
This could be a long shot, but have you considered that this may be a faulty engine/gearbox mount?
From what I could understand you have Sport Chrono package and thus dynamic mounts.

Just a guess.
Yes I have but it seems very unlikely that the mechanics would not check the transmission for obvious faults before fixing the rattle from the interior components. Also PADM faults should show up in the instrument cluster for me to see I guess?
 

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A couple of additional thoughts... first, you describe this as a noise coming from outside the cabin. Porsche sells a DVD with pure tones designed to be played in your car and to trigger vibrations in the cabin. You might try that to verify the source of the noise is not in the cabin.

Second, it is helpful to verify if the forcing function is related to engine speed or wheel speed. You have mentioned 1800 RPM, but you also mention that it happens regularly during your commute. So, there is a possibility that you are inadvertently confusing the source because it happens in the same place at the same speed. You have a few strategies to verify the source: you could hold 1800 RPM in 1st gear, and then also 2nd gear to verify that the vibration is repeatable at that RPM regardless of wheel speed. This will also rule out vibrations caused by road surface forcing your wheels to impart a vibration to the car.

If you confirm that the forcing function is related to engine speed, then a possibility is that your exhaust system is resonating at that speed. There is a resonator balance tube between your twin mufflers that has a sliding connector that can be loosened and moved. If you slide it to one side, exposing a gap, that will change the natural resonance frequency of the exhaust system (and make it louder), and you can use this to test if the source of your noise is being caused by a resonance in your exhaust.

If the noise is confirmed to be engine speed driven, and not from exhaust resonance, then the most likely remaining cause will be something loose outside the cabin. In this case if you have ruled out road surface as the driving force, then you should be able to reproduce the vibration while not moving, by having a confederate hold the engine speed while you walk around the car listening for the noise.

Let us know what you discover.

Cap
 

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Discussion Starter #18
A couple of additional thoughts... first, you describe this as a noise coming from outside the cabin. Porsche sells a DVD with pure tones designed to be played in your car and to trigger vibrations in the cabin. You might try that to verify the source of the noise is not in the cabin.

Second, it is helpful to verify if the forcing function is related to engine speed or wheel speed. You have mentioned 1800 RPM, but you also mention that it happens regularly during your commute. So, there is a possibility that you are inadvertently confusing the source because it happens in the same place at the same speed. You have a few strategies to verify the source: you could hold 1800 RPM in 1st gear, and then also 2nd gear to verify that the vibration is repeatable at that RPM regardless of wheel speed. This will also rule out vibrations caused by road surface forcing your wheels to impart a vibration to the car.

If you confirm that the forcing function is related to engine speed, then a possibility is that your exhaust system is resonating at that speed. There is a resonator balance tube between your twin mufflers that has a sliding connector that can be loosened and moved. If you slide it to one side, exposing a gap, that will change the natural resonance frequency of the exhaust system (and make it louder), and you can use this to test if the source of your noise is being caused by a resonance in your exhaust.

If the noise is confirmed to be engine speed driven, and not from exhaust resonance, then the most likely remaining cause will be something loose outside the cabin. In this case if you have ruled out road surface as the driving force, then you should be able to reproduce the vibration while not moving, by having a confederate hold the engine speed while you walk around the car listening for the noise.

Let us know what you discover.

Cap
Thx, I’ve already fixed road surface and car speed related vibrations with Porsche as mentioned in my initial post, but perhaps I wasn’t too clear about that then. Now it’s only related to engine speeds at or below 1800 rpm paired with gears above second gear in the pdk. Further the pdk gear strategy must be in normal, as well as the engine must be under load, to repeatedly make the rattle appear.
 

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Now it’s only related to engine speeds at or below 1800 rpm paired with gears above second gear in the pdk. Further the pdk gear strategy must be in normal, as well as the engine must be under load, to repeatedly make the rattle appear.
That to me, sounds like the engine is lugging due to the low RPMs.
 

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That to me, sounds like the engine is lugging due to the low RPMs.
Yeah, it does. But it shouldn't lug at that vehicle speed. Maybe a defective waste gate, or variable vane mechanism on the turbo? @AceSeventy Can you get a test drive on another car from your dealer, to see if the other car makes the same noise under the same conditions?
 
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