Yesterday, I was driving my 2008 997.1 gt3 reasonably hard when I thought that maybe something had come loose to start making knocking noises. I would mostly be aware of it when the car was coasting - I assumed it is happening regardless but the engine noise is covering it when I use the throttle. Today I went for a brief ride to check out the noise and it did not seem to manifest itself for quite a while. But when it came up again (after I had driven for quite a while and at times a bit hard) it was very clear and audible. It would happen when the car is driving normally (coasting, otherwise I can't hear) or manoeuvring. Here is a recording that I took - (very very apparent from about 0:25). When I stopped the car in the middle of a parking manoeuvre (1:15 in video), the noise continued as the steering straightened itself a bit.

Any idea what this may be?

 

Might be something on the serpentine belt run where the bearing is making a noise. Remove the airbox and spin all the accessories and pulleys by hand and wiggle them looking for play or noise or lack of smoothness.

What was the oil pressure and temperature at when you heard the noise the other day and what oil are you using and where do you live (was it a hot day)?

 

Many thanks for your response, Petza914.

Now that I re-read my post, I realised that I skipped on the most important part - in fact, I am certain that the noise comes from the front of the car. My bad, I really should have said it, but didn't. Took it for a drive again. Nothing until it had been driven for about 25 miles or so. Then there is knocking and creaking all over the front, whether it be going straight or not. Here is even a video with the car stationary and the noise happening as I nudge the steering.

We also lifted the car up with a local mechanic, took the plastic cover off from underneath and had a quick look - every bit seemed to be in place, nothing seemingly broken or detached. He applied grease on the sway bar bushings. That was to no avail - this was before the drive on which I concluded that the noise is still there.

 

Does the GT3 have the same top mount with rubber as the standard 997? If so, check the top of the strut mount, I have coilovers on mine and the rubber separated/broke, so the top of the strut was bouncing around.

Could also be the sway bar mounting points.

 

What is the speed range when this happens?
It almost sounds like a plastic part is flapping in the wind.

 

Just got exact same problem on my 997.1 gt3, 2007 43.000 miles.

Only when warm I think. Even rattle after stopping sometimes. Seem to be a common problem with rattle from the front on these cars after searching the problem

 

Did you sort this out?

 

Unfortunately - never got it sorted. Took the car to Porsche. They looked at it said nothing was knocking. Eventually warmed it up, showed the noise to them, they said that they would lube some parts of the suspension. That didn't help so they decided to change the rubber parts that are on top of the suspension (not sure what they are called). They said that warranty would cover it but anyways decided to charge me for it. The noise has never gone away, but I take it it's a sports car and enjoy it for what it is - which is a great drive when I get to drive it.

 

What many people have told me other places is that the DU bushes in the bilstein shocks are going bad. I have posted videos on other forums with exact same sound. Many people told me they changed front dampers and all fine.

i have lubricated swaybar bushings and porsche center did not found any problems in front at all after two times at workshop. I Just dont get it

 

I don't have the time to deal with it, unfortunately, but all I gather is that Porsche Center is not the go to place for such an issue.

 

Do you think this is the same sound?

 

Certainly not dissimilar. Only when warm, after a while of driving and unrelated to engine activity.

 

This noise also happens to me when warm, more so on hotter summer days, and not related to engine temperature.
I think it might just be the frunk, since the sound is so similar to yours.
I got it to be less frequent by adjusting the bumper stops on the frunk; it happens less often now.

It could still be the front suspension components, as you suggested here, because anything "thumping" in the front area of the car may resonate the same way (kind of how hitting a drum with different kinds of sticks sounds very similar).

Another possibility, in addition to the frunk and bumper stops or suspension, is the frunk latch mechanism. It is such a poorly designed part for such an expensive car! Just a more few minutes of design thought could have eliminated this sound (see attachment). I could imagine this rattling as ambient temperatures increase, and other parts expand. I'm trying to figure out a good way of silencing this particular rattle.

 

Good one to try. Thanks for the suggestion. Unfortunately, I am storing the car abroad for the moment Can't wait to get back to it.

 

These cars are too enjoyable to drive -- storage is a bummer!
But yours is a GT3, so I get it.

If I figure out a good way to dampen the rickety latch without disassembling it, I'll let you know.