981 Cayman hatch rattle/creak - goes away after a few miles?

[Twinfan]

Bit of an odd one this, has anyone had anything similar?

My 981 Cayman has a very noticeable creak/rattle from a cold start which comes from the rear of the car. It sounds like the boot/engine hatch to me. However, once I've travelled a few miles and the car is up to temperature it seems to go away and I can't make it return by using too high a gear, going over rough tarmac, letting the revs rise or drop etc.

I've adjusted the bump stops which makes no difference - the noise appears then disappears whatever I do. Once the car is left to cool right down again (overnight at least) and started again the noise returns.

Any suggestions as to what it might be?

 

[Buddy]

Hi David, you've already addressed the first step in this by checking the stop pegs which I expect you confirmed are seating but are they split? It's a common thing and sometimes they are with no problems sometimes otherwise. Mine have split but no rattles or squeaks so I leave it well alone for the time being.

Check that the hatch is actually down onto the seal you can do that by smearing some petroleum jelly or such onto the seal then closing it using the minimum of force ( best to leave a door or window open so that you don't have to press the lid down ) then open it and see how wide the witness is on the hatch from the seal making contact, another source of such noise is if the privacy screen is tapping against anything it can cause a tapping noise.

 

[Twinfan]

The car is only 18 months old and the stops are intact - no splits. The closure is quite firm so I'm pretty sure it's making contact OK.

I did wonder about the privacy screen. I think I need to remove it and go for a drive...

 

[Andy Barr]

Hi David

I have experienced a similar rattle from the rear hatch on my 987 CR. Usually from cold start. If I stop anywhere once car is warmed up and open/re-close rear hatch, the rattle disappears.

I think it’s down to a cold rear hatch rubber seal which gets hard when cold and softer once cabin is warmed up.

Try opening/re-closing the rear hatch once car and cabin are warmed up.

cheers

Andy Barr

 

[Twinfan]

Thanks Andy - something like that would make a lot of sense...

 

[Motorhead]

Perhaps the application of a rubber lubricant to the seal would help David..!

http://www.halfords.com/motoring/engine-oils-fluids/grease/halfords-silicone-lubricant-400ml#

Jeff

 

[Twinfan]

Yep - may give that a try []

 

[alastairp]

I understand that there is a device associated with the stability control system that detects acceleration/ deceleration/ lateral force that is effectively a ball in a container and this is located at the rear of the car and it is not unknown for this to rattle sometimes and is often confused with loose trim or rear hatch.

Don't shoot me down, but worth considering.

 

[Twinfan]

Interesting - I wonder where that is?

 

[Motorhead]

I'm not sure about that device David, but there's a known source of hatch rattles on the 987-series cars:

https://www.porscheclubgb.com/forum/tm.aspx?m=825057

The so-called mass damper (or tuned absorber) is designed to damp a low frequency panel resonance of the rear hatch. I don't know if a similar device is fitted to the 981-series cars.

Jeff

 

[Bilko1]

On my last CS it was the oil and water top up covers that creaked exactly as you've described. I put on a tiny bit of olive oil (!) and it stopped them creaking

Chris

 

[JohnCRS]

Having moved from a 987 to a 981, the hatches seem quite different in the cause of rattles. Common to both is the fact that these lower temperatures do allow things to rattle until warm. I have found that the 981 is best when the hatch closes easily rather than requiring pressure in the lid, i.e. the opposite of the front, so you could try screwing the pads in to take the load off. I also find silicone spray helps all seals.

 

[Twinfan]

I have found that the 981 is best when the hatch closes easily rather than requiring pressure in the lid, i.e. the opposite of the front, so you could try screwing the pads in to take the load off.

Winner winner, chicken dinner! This seems to have done the trick. I think having the bump stops quite far out doesn't allow the hatch mechanism to fully lock into place. A few miles/bumps of driving though, and it settles in. Winding in the stops a bit seems to have cured it, certainly for the last couple of times I've been out in the car, so many thanks John!

I still have a very slight rattle from the interior trim of the passenger door which my OPC have worked on previously, so I think I'll get them to look at it again when it goes in for its first service in a few months.

 

[JohnCRS]

Good to hear when something works. Thanks for letting us know.

As for the door, I never did cure that rattle. It was the driver's side on mine. It always sounded as if it was at the top of the door near the mirror switch, or possibly around the air vent in the end of the dashboard. All I can say from experience is that the mirror switch innards are very fragile!

 

[AndrewCS]

I had / have a slight rattle from somewhere on the passenger side, engaging the seat belt cures it ... most of the time.

 

[Twinfan]

The door one for me is odd. I thought it was the dash at first, around the cup holders, but my OPC cured it and they said it was the door. It's come back though unfortunately. It's more of a creak than a rattle so I'm assuming it's two plastic parts rubbing. I can trigger it by accelerating at 2000rpm when the resonance sets it off.

Very minor in the grand scheme of things, just mildly annoying...

 

[Brian_Innes]

Regarding rattles from the passenger side, the stowed seat belt buckle can sometimes rattle against the passenger seat, and if the empty passenger seat is set fully back on the runners, some chaffing creaks sometimes occur.

A very good tip on the hatch rattle cure John.

Brian

 

[Strasbourg]

Oh dreaded rattles. My 981 developed a rattle somewhere around the rear hatch. It seemed to be inconsistent other than certain road surfaces accentuated it. After my meagre attempts to cure it I visited my local PC. They suggested it was trim related and took various parts out, taped them prior to refitting. It has made a pleasant difference though they stated the noise may still be heard on very rough surfaces. I am sure they have come across this before hence their remedy. Fortunately I am a touch deaf so that may be a contributing factor too.

Every car my wife and I have ever owned, except a Saab 900, has developed a rattle to drive us mad. My 993 C2, come to think of it, was very taught an rattle free. The occassional squeaky suspension bush could be heard after a spell of inactivity. A short run cured it. A fabulous car but as I have become older rather too demanding to drive long distances hence the Cayman. The 981 Cayman chassis dynamics are quite the best I have ever experienced. Porsche's best without a shaddow of doubt though 991 drivers and GT3 enthusiasts will probably question that.