ltc

My Cayenne has a service appointment for Monday, but I was wondering if anyone else has had this problem, or knows if there are any Porsche TSB's?

There is no front end nor steering wheel vibration, it is definitely from the back. As in a previous post, it is felt on the console/armrest as a high frequency, low amplitude vibration with an accompanying droning sound.
Below 60 it is not there, above 80 or so it mostly goes away.

It seems to have developed all of a sudden. I'm running Porsche 18" Cayenne s rims with Dunlop GrandTrek (purchased from my dealer for $2k).

Thanks.

WCS

My car has this problem recently.. and yes it seems to show up after replacing all four tires. The droning sound is very low frequency right?

I believe it is the cardan shaft problem mentioned in the other threads. My dealer is checking on my VIN and part number with Porsche tech to see if my S needs an update.

Refer to this thread for part number:
http://www.renntech.org/forums/index...t=0&#entry3686

And this thread for some other owner's experiences:
https://rennlist.com/forums/showthre...hreadid=107530

mudman2

FYI PCA internal notes state that VIN number ID is used to identify the suspect shaft.

This is not in fact accurate, which your dealer will find out buy digging deeper. The only way to know for sure is to eyeball the stamped part number on the shaft as it changed.

WCS

But overall it is safe to say that all '03 S has this issue, right?

mudman2

Yes

Toby Pennycuff

Applies to some 04 models as well. Mine is an 04 and the cardan shaft is on order from Porsche.

TBP

ltc

Update,

Yup, it's the Cardan shaft. None in the US, best guess is 5-10 days.

FYI, Cayenne has 8K miles, vibration developed at around 7K miles.

KY_soldier

Lewis, my dealer ordered mine last week, not here yet. Back to a previous question I had on another thread for you, what do you think would cause MP3s to sound staticky/crackly, while my satellite radio sounds great (also compressed digital audio), both from the same FM modulator source?

GO PATS!!!

ltc

Toby,
How long do you think before you start seeing Cardan shafts up on eBay, or dealers reporting that Cardan shafts are being stolen off Cayennes on the lot

KY_Soldier,
It could be several things (shielding/grounding/RFI, etc), but my first guess would be line level mismatch; i.e. the analog output level of your MP3 player is much higher than that of your satellite receiver. If the input to the modulator were overdriven, you could hear what I believe you are describing.
If you turn down the volume of the MP3 player, do you get decent audio performance? Are you connecting to the FM modulator via the headphone output jack or a line out jack?
Feel free to email or PM me if you have any further problems or questions, I'll be glad to help.

Toby Pennycuff

Lewis,

Don't believe for one second that I don't already have a defined search set up!

TBP

mudman2

Based on my personal experience, I do not think the cardan shaft is responsible for any vibration over 60. I believe that all stems from alignment issues and the tight tolerances the dealers have to content with.

my 2c

ltc

Mudman2,

I had my dealer do a complete alignment to the new/updated factory specs (I paid for it). The vibration did not change, although the car is less prone to tramlining on crested/grooved highways. After the alignment, they road tested and found there was no reduction in vibration.

The dealer then tried to realign the Cardan shaft with a new alignment fixture, supplied by Porsche. This resulted in a reduction in vibration, but it is still present within the same speed range, only now you feel it on the console and less in the seat of the pants.
At this point, they concluded there was nothing left to do other than order the Cardan shaft. I think 5-10 days is optimistic, but who knows.

They told me that PCNA has still not officially recognized the Cardan shaft as an issue, however Porsche in Germany is beginning to stock Cardan shafts.

As I mentioned previously, I put a spectrum analyzer in the car (ah, the life of a nerd) and concluded that the vibration was correlated to driveline and not tires (based on geometries, speed and frequencies).

However, I have no insight as to what could be happening to the Cardan shaft over time, as the car went 7000 miles with no vibration.
My primary concern is that this is a latent materials defect and will eventually show up on a large portion of Cayennes; Porsche may already know this and will not recognize the issue until a containment plan and material is in place., given the large portion of revenue the Cayenne is providing Porsche. The last thing they want is a recall or large field issue (similar to the 996 rear main seal).

Only time will tell.

mudman2

Lewis

Don't get me wrong I lived with the problem for 6 months before we figured it out with help from a friend in Germany and my dealer.

I had had the sound a long time and know it intimately, a bit like a twin Cessna with the props out of synch, and in fact posed the question of the low F harmonic noise on the boards in June 03. It only turned into vibration after about 5000 miles but the vibration was very slight.

My Cardan Shaft has been changed BUT the main difference I see is in the noise.

I did have a major vibration problem at the same time, at about 9000 miles. They condemned 2 tires and replaced them (dealer discretion) but it took them 2 times to get the tires and wheels load force balanced. The first time balance failed because the tire needed to be turned around on the wheel and redone.

The alignment numbers used were direct from Porsche not from the TSB, when that was done I got the car back BEFORE the shaft arrived so for a weekend I drove like that.

The major rear vibration was gone... UNTIL the suspension geometry changed under load then it came back again, especially when it crouched down on the freeway. The shimmy also moved around the speed range, I could not get a vibration free speed below 95 where I could use cruise for very long at all.

On the Monday I took it back they replaced the shaft and re aligned it again and now its like a rock at all speeds and levels.

Before it was changed the noise / vibration from the shaft was gone by 60mph and only started at just over 40.

I had had the sound a long time and know it intimately, a bit like a twin Cessna with the props out of synch, and in fact posed the question of the low F harmonic noise on the boards in June 03.

It may be drive train but it does not sound like the shaft.

ltc

Mudman2,

Thanks for the additional info. I normally don't adjust ride height (normal with my 18" winter tires, low with the 20" summer tires), so I'll have to try that once the roads clear up here.

Strange, but I don't really have any sounds, just a vibration. It may not be the Cardan shaft, it could be a bearing. Hard to be 100% certain.

I do not know if the alignment was done to Porsche specs or the TSB; I normally just trust my dealer to the details.

When you said realignment on last Monday, was that shaft realignment or wheel/tire realignment?

I am glad to hear that you were able to completely eliminate the problem.

mudman2

Sorry I was not clear.

The Shaft came in on the same Monday that my Wheel/Tracking etc was going to be re-done following my 500 mile road test that weekend.

concidence only

The "wummering" noise is almost like a throb at very lowF, drove my wife nuts (better hearing than me I guess.

Say the word 3 times, you'll get it.