Bradinthe56

I've developed a 'clunk' somewhere in the front suspension. Happens most when the left front hits a bump or anything with a rougher transition (i.e., make the suspension move a small amount, quickly). I get it a little when the right side hits first, but less noise. Can't feel a thing through the steering wheel, tracks as straight as the day it got a fresh alignment. My indie said he checked/looked around but also said he didn't see anything and was guessing it isn't mechanical. Given there is nothing in the frunk I'm thinking it HAS to be mechanical.
So, when I put it up on stands, what should I be looking for?
Oh, 2009 C2S PDK 44500 miles.

Bruce In Philly

2009 C2S 148K miles

Could be a bunch of different things.... tough. Your suspension has to be loaded with the weight of the car for it to happen as the bushings go bad.... up on a jack you are not going to find anything unless it is realy realy bad. A high probability it is the lower control arm (#6 upper pic) or the sway bar links (#5 lower pic) although links click more than clunk. If you want to throw parts at the problem, order the lower arm and the links... the links are not that expensive. Else, the only way to be sure is to use chassis ears. The shop foreman at the dealer used to use them. I purchased a set to diagnose some problems... I got tired of guessing. BTW, I buy OEM TRW or other OEM parts for suspension arms... I never buy the Porsche-labeled units.

A dealer will do usually one of two things to diagnose the problem 1) chassis ears, or 2) they will guess based on their experience of the most common culprit. You can always stop in a the dealer and just ask them. Sometimes they tell you. My dealer's service manager is pretty upfront and a helpful guy... he actually called the shop foreman out to talk to me and that was after I told him I was going to DIY my issue. Yes, some are pretty cool that way.

Read up here... the ears cost $100. https://rennlist.com/forums/997-foru...ed-advice.html

Below are schematics from the Porsche parts Katalog... there are more pics to understand all the connected components, but these are the most likely culprits. the parts here may not be yours, you must confirm for yourself.... you should download it for your own reference from here: https://www.porsche.com/usa/accessor...artscatalogue/

Peace
Bruce in Philly

aaks38

Check you upper strut mounts, the rubber dry rots and strut rod hits against the plate, its a bit hard to see without removing the strut assembly.

Wayne Smith

The upper strut mounts on my 2010 C4S had to be replaced at 120K miles. But the geometry on the all wheel drive is different than the two wheel drive and puts more stress on the mounts.

Petza914

Also check the sway bar drop links.

scadams

Generally I’d say it’s a good idea to get under there and check all the mounts and bushings. My ‘09 C2S is at 116k mi and I had a good look underneath recently and my front left mount, front bump stops, and f&r drop link bushings all need replacing.
Aftermarket mounts, links, and bushings are an option but if you’re happy with OEM handling, OEM/OEM supplier parts will run you less.

roman944

my "clunk" over bumps came on because whoever had the car before me had factory shocks and H*R springs, and shock mounts were on up-side-down and shot

replaced with new ones and coilover suspension no more clunking noises

swingwing

Easiest, cheapest things first: Look at sway bar links. Upper strut mounts are next. For comparison my ‘09 C2 is tight as a drum at 44k miles. Not in love though with the Pirelli P Zeroes put on by PO. It’s a rough ride I’ll tell ya - gets me ponderin’ about a Macan S.

TractControlOff

I experienced a similar situation shortly after purchasing my .1 C2S. I thought my bushings were going bad, but it turned out to be a loose tie rod. 3k+ miles later, it hasn't been a problem again...yet!
Just another idea.

Bradinthe56

Thought I'd post an update after replacing the sway bar links: no change
I think my next step is to take it to the dealer as see if they can diagnose with confidence. The weird thing in all of this is that, in all my past experience with suspensions/bushings/etc. being loose is you can feel the 'clunk' through the steering wheel - especially something like a tie rod end. Also, with an alignment done only about 4k ago, you would think a loose/sloppy tie rod or even LCA might/would be apparent to the tech.

Bruce In Philly

The way my dealer found a clunk in my 2000 Boxster S was to use chassis ears.... really the only way. Otherwise, a dealer would be using his/her experience (a good thing) or they guess. Don't be too hard on a tech for not finding it.... it is almost impossible unless there is an obvious tear. In the old days, you could just put a tire iron in their and start applying pressure on the rods.... you would see them move. On our cars, the bushings are so hard that the thing would have to be pretty far gone to see it that way.

Read about chassis ears here: https://rennlist.com/forums/997-foru...ed-advice.html

Let us know what they found. BTW, most folks say to replace the links.... I never had them go bad in over 350K miles of two Porsches.

Peace
Bruce in Philly

scadams

My clunk was from the front left strut mount. Replaced all of my mounts with monoballs and put on B16s. No more clunk.

Wayne Smith

One of the reasons the upper strut mount was mentioned. Clunk without feedback.

Bradinthe56

Wondering exactly what is meant by "upper strut mount." I had Tarett strut mounts installed about two years ago to allow more negative camber to be dialed in. I can't imagine one of Tarett's products failing that fast (maybe 10000 miles). While searching around Pelican, I did notice there are some other pieces which I'm imagining could be at issue: 'rubber bump stop' and 'shock bearing plate' pictured below:
Select
All Category Description Price Quantity Subtotal Move to Cart [Clunk]

This part fits your 2009 Porsche 911 Carrera S Coupe

996-343-301-02-M260 Rubber Bump Stop (Bushing) for Strut (Front Left or Right)
[More Info]$12.00

$24.00

[Clunk] This part fits your 2009 Porsche 911 Carrera S Coupe


996-343-515-05-M100 Shock Bearing Plate (Plastic Ring with Ball Bearings) (Front Upper Left or Right)
[More Info]$42.92

$85.84

Any additional advice? I am also planning on going to the Porsche dealer and see if they have and can use ears on the front suspension to track this down.

Petza914

The bump stop in the first picture is a cushion for when the shock is driven through all it's travel so instead of banging hard when there is no travel remaining, it uses that foam snubber as a cushion. If your bump stop is in place and not deteriorated to where it's hard and crumbling apart, then it's still doing it's job and that's not the issue.

The second picture looks like it's a ball bearing plate that probably resides between the spring perch and spring so that the spring can twist a little as the front wheels are turned instead of being locked in a fixed position and binding up. I added roller thrust bearings under my front springs on my Bilsteins to accomplish the same things as I don't believe these are in the 997.1 stock suspension (maybe they are) but there wasn't anything like them in the Bilstein Damptronics kit.

The Tarett monoball top mounts are pretty robust, but there isn't any rubber in them, which is why they control the suspension angles better. If you installed them a couple years ago but didn't have the noise and do, I would doubt it is those unless one of the bolts that mounts the Tarret plate to the car has come loose, then it absolutely could be that as the plate moves up and down. These plates are a little tricky to install the way they're designed because if you tighten the nuts from the top they can actually spin he stud underneath, which means you haven't really tightened anything. You need to tighten the nut from the top while holding the portion under the fender. If they weren't properly tightened this way, it's possible one of the nuts has worked loose just enough to cause a clunk on big hits.