Folks,

I went through lots of pain and spent a ton of time on research before coming up with a simple solution to a very annoying problem that Cayman has, and wanted to share the solution.

Problem Symptoms: air buffeting (similar to that when you open rear windows in mini van or SUV) / air pressure modulation / slight thumping sensations of eardrums when driving on non-ideally smooth surfaces, mostly at speeds of about 20 to 50 MPH. While fewer than half of people perceive this as a problem, I assure you that close to 100% would see a big difference once it's solved. Further, note that harsher suspension (e.g., lack of PASM, 19" wheels, custom harder suspension, stronger side-walls tires, etc.) make the problem worse.

Problem Cause: The rear hatch of Cayman is huge and heavy and, as it comes from the factory, attaches to the body (in closed state) only by 4 small rubber legs (2 on the sides and 2 on the bottom), besides the permanent attachment points. This leads to the hatch shifting very slightly out-of-sync with the vehicle body on bumps, essentially placing the people in the cabin inside a giant very low frequency speaker.

Solution: I can imagine numerous possible solutions, with the most preferable, of course, being the Porsche engineers fixing this in some way at the factory. All that has to happen is the the free play between the hatch and the body, small as it is, has to be almost completely eliminated. An easy, cheap, and completely and easily reversible solution I found was as follows:

1) Buy the thick felt padding self-adhesive sheets at Home Depot in two shapes -- about 3/4" circles and slightly over 1/4" wide strips of 6" long or so.
2) The round pads (2 of them) go into the round openings where the rubber adjustable "legs" of the hatch go when you close the hatch. Note that the top of the felt tips became almost exactly level with the surrounding metal. The felt circles are a tiny bit larger than the openings, so a bit of effort is needed to get them all the way in. Use something hard but slightly padded and not sharp.
3) Find the 2 rubber non-adjustable legs on the sides of the hatch, and then find the places on the body where they come into contact when the patch closes. On my car, there are strips of thick transparent protective tape there. Cut to size 2 short pieces of the 1/4" or so linear strips of felt and attach there. The goal is to make the leg rest on this newly elevated surface.

It is possible that this specific self-adhesive felt material is not going to stand up to weather too well. In that case, it can easily be replaced with more weather-resistant padding. The idea is very simple -- use padding to brace the hatch harder so it has less room for jumping up and down.

In addition to this, I also bought the thickest and most expensive (it was like $15) roll of self adhesive weather stripping at Home Depot and attached it all the way around the perimeter of the hatch, but in retrospect that really most likely was not necessary.

That's all there was to it. No more buffeting/cabin pressure modulation -- the feeling of being inside the cabin is night and day different. Enjoy!

 

Thanks for posting this. I first test-drove a Cayman a few years back and the car instantly gave me a headache due to this sound. It reminded me of riding in the back of a car with the speakers at your ears.

Last week I had the chance to check out an 09 Cayman and it was much quieter in general, and it lacked the boom sound.

My question is, how well does your fix work? Does it eliminate the boom completely? Also, are the 09 and up cars different in the hatch or is it luck of the draw from car to car?

Thanks!

Joshua

 

Replying to Joshua's questions:

> Last week I had the chance to check out an 09 Cayman and it was much quieter in general, and it lacked the boom sound.

It may have been PASM, 18" vs 19" wheels, or smoother roads. Also, I have only been exposed to 2009+ Caymans (though 4 of them in total, and all had this problem, though non-PASM one had it the most).

> My question is, how well does your fix work? Does it eliminate the boom completely?

I am very sensitive to this issue, and it solved to 100% to my satisfaction. All people are different, though, so you may need more bracing than me. This is easy to arrange, however, by simply using even more padding material. Just be careful not to add all of it at once and then forcefully slam the hatch down -- be gentle in your experiments.

> Also, are the 09 and up cars different in the hatch or is it luck of the draw from car to car?

It is my understanding that '09+ cars have a non-adjustable hatch latch lock (the latch sits inside the opening in the body, and, apparently, thus it was possible to adjust the position of the latch lock to minimize the hatch travel. However, I don't think it solved the problem 100%, it did not brace the latch in nearly as many places as my fix (1 vs. 4), and pre-'09 Caymans have issues with oil supply to the engine for track use, which removed them from my consideration.

Cheers,
sergey

 

Well now I can get to searching for the right car. I test drove a Boxster yesterday. It was nice but i think I'd rather have the Cayman. Im hoping to find a nice euthisiast owned, 1 owner, 09 S.

 

Can you possibly take pictures of your set up with the felt in place?

 

Sergey,
Many thanks for this information.
My wife complained of symptoms identical to those you described so much so she refused to drive our Son's 2010 Cayman.
I followed your simple instructions to the letter and completely cured the problem - took me about 20 min to complete.
It was difficult to believe that such a simple fix would cure such a problematic issue, but it did 100%.
Top Man

Phil

 

Does the padding make the hatch more difficult to close?

 

Subscribed for pictures of installation

 

Bigwong - Hi,
Yes it did initially, but I just very slightly unwound the spring tension on the two rear rubber blocks so it closes quite easily now.
Perhaps as the felt 'beds in' and weathers it might be necessary to increase the spring tension again - I am sure my wife will let me know if that horrible sensation returns.
As Sergey suggests my Son who owns the Caymen did not realise there was a problem but he immediately noticed the difference when I fixed it.
Regards
Phil