I have had my CS serviced for the "trunk clunk" three times. The first time the clunk remained and they added some squeaks and rattles. The second time they fixed the Clunk, but I now get a boom. The third time fixed the squeaks and rattles, but still have the boom. The boom is similar to a sub-woofer sound and occurs on uneven surface streets. The mechanic told me he wrapped the weight with weather stripping as noted in the "Porsche - Stopping the Hatch - "Clunk"" article that is on this web site. My question is has anyone stopped the boom or should I just live with it?

The Boom is well documented / commented on here and I have posted a bit about it. Suffice to say there is no fix other than wind down the window a bit. Porsche needs to do some serious changes to fix it.

I have reviewed the past posts regarding the trunk thump. Many are almost 2 years old. I can see how this would be a boring topic for the long time member. The one thing that I am having trouble finding is a difinitive answer as to how to stop the clunk or boom.

The dealer performed the weather stripping around the weight fix and I think the booming is worse than the clunk. I will attempt the o-ring fix on my own this weekend and post an update next week.

Vision 1110,
Be aware of the fact that the weight is really a vibration absorber. Its free out-of-phase movement is a prerequisite for its functionality. The more its movement is reduced or even stopped, the more the boom will increase, since the absorber will progressively turn into a stationary mass in the middle of the hatch and start to resonate in-phase with the hatch vibrations.
If your dealer did the mod without understanding the concept of an absorber, please check if the used foam strips are too thick and rub against the metal cutout surrounding the weight. This would block its free up-and-down movement - exactly what you don't want. You want the foam to just dampen any impact against the hatch at the limits of the weight's suspension travel.

__________________
Greetings Rainer
...and may there always be a palm of air around your sheetmetal...

I took the hatch apart today. The instructions by Rainer were excellent. I am a CPA and if I can do it..... It was very interesting to see what "fix" the dealer had performed.

The dealer uses a felt-like tape and covered the perimeter of the counter weight. They then removed the weight an put foam tape in the well where the weight sits. There was no foam tape on the weight. Trust me that this does not work! The weight wobbled very easily when manipulated by hand.

I had shown the dealer the Rainer fix and they said that was what they performed. The other Porshe dealer in town is forty miles to the north. It will probably be worth the trip next time I need service.

I guess I can not follow instructions well. Rainer's instructions were so good that it would not be that hard to remove the panel again, so I did my own experiment.

I left what the dealer had done and added the O-rings to the mix. (sorry. but Stevie said he had no BOOM). I put two on each side of the weight and re-attached the weight to the car. While I had the panel off I put some strips of foam in the wells of the hatch. I am surprised that there is no sound proofing on the hatch. The engineers can tell me if I added a 1/4 pound to the weight of the car for no reason.

I took the car for a test drive and looked for uneven pavement. I drove for about twenty minutes and had no BOOM or Clunk. I can not tell if I just did not drive on the right streets to get the boom, but it seems fixed. I will commute on Monday and I know that drive gets the boom. I will update on Monday.

I will be meeting with a regional rep. to hear Porsche's official response to the trunk clunk problem. My dealer gave up after ony two attempts to fix the noise. Like many of you, the clunk was fixed, only to be replaced by an annoying booming sound. Here in Southern California, the freeways cause the car to boom so badly it's like being inside a huge drum. My guess is that the whole exterior panel is not stiff enough.

Regardless, after a clutch/pressure plate failure, a broken rear quarter window bolt, periodic radio and power window gremlins and the usual remote keyless issues, I'm ready to have Porsche step in and get my car sorted out.

I still like the Cayman, but the ownership experience is not good. Much of this can be traced to my dealership (Circle Porsche, Long Beach, CA), so lets see if the company offers any relief from the last remaining problem.

Commute update: I would say that I have corrected 85% of the boom. There still seems to be a boom on certain streets. As of now there is no boom on highways, across rail tracks and most surface streets. There is a slight boom on some downtown San Diego streets. The boom is much shorter in duration.

My wife is driving the CS today and I am driving my five year old crew cab pick-up truck with no rattles. I will get her less biased opinion tonight.

my approach to the trunk clunk issue was this: it's by design. Just like the engine is not silent, the use of a counterweight to minimize (a very lightweight) hatch movement up and down has the side effect of a little clunk.

With that, I can live with and accept trunk clunk.

My final solution to the problem is as follows:

• Dyanamat on inside of hatch.
• Either the o-ring or the weather stripping fix for the weight.
• Relocation of the latch to the half way point.

The dynamat may have been overkill. It has drastically improved the overall experience with the car.


My observations:

Dealers are in collusion to deny this problem. It is improbable that they all have the same party line when it come to the thump problem.

The weight is NOT a brilliant design.

Never owned a car with so many squeaks and rattles.

The cabin is an Echo chamber that magnifies sounds. Put a red bull can in the cup holder and the clinking is deafening.

Quote form mechanic at dealer on test drive for thump " they try to make the cars light and they all rattle in the end."

My neighbors thought I was nuts for ripping into a hatch of a brand new car.

Suspect that people who do not have the thump are older and can not hear well.


IN THE END

It is beautiful car that is a blast to drive. Guys rubberneck to look at it, women run their fingers through their hair and kids smile when it goes by......

After two tries at the dealership I pretty much went with your philosophy. Lately I haven't heard the clunk. I don't know if it is because it has gone away or because I just don't pay attention to it.

Vision - can you elaborate on the effect of the dynamat? I mess with car stereos and was wondering if dynamating the hatch would do anything.