Knocking/Clunking from front-end

My 2002 C2 has about 90k miles on it. I've noticed a clunking/knocking from the front. Generally, it seems to happen when warm. It doesn't have to be going over bumps, it could be while braking, but I definitely experience over bumps, road imperfections. It is a noise as well as a feel particularly in the pedals and a little in the steering. With the car up in the air, I thought I had some play in the wheels, but that was probably just the steering lock (doh!) However, I did notice that the driver side drop link rubber boots were torn so I replaced it but no change. Everything else looks OK. I've seen a few posts about this (like this one ) and had convinced myself that I should replace the inner and outer tie rods. To this end, I have these parts and a passenger side drop link arriving tomorrow. However, further reading indicates that it might be something else: control arms, track rods and/or shock mounts. My indy is suggesting the shock mount because he says he's personally not seen much in the way of issues with tie rods or control arms on 996s compared to shock mounts. Admittedly the car has 90k miles on it and it is pretty likely that no part with rubber bushings is going to be performing at 100%. However, I'd rather not just throw parts at it especially since virtually everything I do is going to require an alignment. So here are my questions: 1. What diagnostics can I perform without tearing the suspension apart? From what I've read, the bushings tend to look OK even when they're not and you can't really see the play unless you have the parts off. 2. If I start to go in and replace stuff without a diagnosis, should I (i) Do the inner and outer tie rods ($200 which I've already spent) (ii) Also do the strut mounts (another $60), (iii) Add the control arms and track rods as well (another $500-1000 depending on whether I go Meyle or Porsche)?

Put the car back on the lift. With a pry bar or breaker bar, you should be able to notice excessive slop or play in the front suspension. Give it a try -- it doesn't cost you anything, and you can't break anything. This video of a Mercedes AMG E55 goes over how you can check ball joints; the same principles should apply elsewhere: video

Thanks numbah9 - good video.

I chased the same problem for quite a while. This is what fixed it: http://www.ebay.com/itm/Porsche-Upda...1Y03jH&vxp=mtr

Thanks Mark I. I'm going to attack the suspension with a pipe wrench and breaker bar to see what has play in it.

As you point out, it could be a lot of things ... certainly, control arms wouldn't surprise me given the mileage. I had a pretty solid clunk in the front and got off cheap (sway bar links), but I'm expecting to replace the front control arms and control arm links fairly soon.

It could be something as simple as just worn sway bar bushings. I went through my front suspension last winter and replaced most of the wear items and had the car re-aligned. Found out my clunk was because my sway bar bushings were the wrong diameter (a little too big, wrong part number) put in the correct ones and fixed my clunking noise.

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As others have said, prying/pushing/pulling on things may help identify where the noise is coming from. I was pretty unsuccessful with this approach. I had a clunk from both the front and the rear, and based on other posts, I decided to replace the diagonal, forked control arms. This successfully cured my problem, but there's no way I could diagnose it effectively before just trying the new parts: https://rennlist.com/forums/996-foru...-arms-wow.html Once the forked arms are off the car, I could clamp the ball joint in a vise and pull axially on the control arm and feel it knocking. It would be VERY hard to get this motion while it's in the car because you'd need to be pulling the entire hub/brake/shock assembly rearward and forward while feeling for play; pretty hard to do. The motion in my completely played-out parts was less than 1/16"; very hard to see even with the parts off the car, but very easy to hear once the part was in a vise. These arms can be removed from the car in about 5 minutes, so you could take them off, bench-test them, and then decide whether that is your problem. On the updated EPS design posted above, be careful with these; understand that this a completely different design which replaces a freely-rotating ball joint with a urethane bushing. This significantly adds spring rate to your car. Maybe you want that and maybe you don't; it depends on what you're doing with your car. Just something to be aware of, that just because it is an "updated" part advertised as being "better" and costing less than the OE-style part, it may or may not be a good deal for your application.

The knocking/clunking is related to your suspension. I know because I recently replaced almost every single component on my 2002 996 C2 and that cleared up several problems including the squeaking /clunking / ride / etc. If your suspension (springs / shocks) is original, it's done. If the rubber bushings on your vehicle are original they are done and need to be replaced. There is no way rubber bushings that are over 15 years old and 90,000 miles are still performing as intended in any way. No one likes spending thousands on their car, including me, but the facts are the facts. There is nothing cheap about owning any 911 (of any year) and my experience is $2,500 a year in maintenance on average. I've spent, who knows, $8,000 in the last 2 years. You either pay up front ($100k for a new one) or you pay as you go to maintain an old one. If you are going to keep the car just replace everything and be done with it. $5,000.

This is all good advice so thanks. I'm well aware of maintenance costs. As I explain to everyone who asks me about getting one, the price of entry is cheap but it is still a Porsche with the ensuing parts and labor costs. I just spent $400 on the turn signal switch part for example.

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Yes, I saw that too. I would replace with either the original style part. I see that JP Dansk and Meyle both do Porsche-style parts. Design911 in the UK has a set of both the track rods (coffin), lower control arms (tuning forks) and hardware for $455 shipped to the US. Or I could get the Porsche parts for ~$1000 from Sunset. I've read various opinions about Meyle.

Tighten all your lugs?? Had clunking / knocking on my rear passenger and turned out to be a wheel that wasn't properly fixed.

"On the updated EPS design posted above, be careful with these; understand that this a completely different design which replaces a freely-rotating ball joint with a urethane bushing. This significantly adds spring rate to your car. Maybe you want that and maybe you don't; it depends on what you're doing with your car. Just something to be aware of, that just because it is an "updated" part advertised as being "better" and costing less than the OE-style part, it may or may not be a good deal for your application." The "tuning fork" control arm (#3 in this diagram) http://www.autoatlanta.com/porsche-p...section=401-00 Does not have a "freely-rotating ball joint" ... it's a rubber bushing - the EPS arm replaces the rubber with urethane (= stiffer). Whether this is "better" or "worse" is up for debate, but your claim that the stock arm has a ball joint renders your argument moot...

Last spring I had some clunking and way too much toe in that had worn out the front tires in only15,000 miles, and with 87,000 miles on a 2000 car I decided to replace the lower control arms (coffin arms), the upper control/diagonal arms and the tie rods, inner and outer. Then had the car aligned. Handled great p, etc, but I still had a clunking that I could not find. I thought it might be the upper strut mount, which were replaced when I put on PSS10s several years ago, so I started to take off the struts. To do this I had to take off the front sway bar links and discovered that one was lose at the sway bar. You could not feel it with ehsuspension hanging. Replaced the link and the clunk was gone. It can be very hard to find these noises with the suspension together, weighted on the ground or hanging on a lift. By he way I found the Meyle lowers on line for about $110. Good luck.

Great thread, gentlemen!! Thanks to all of you.

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Good suggestion but they are torqued up properly.

Dharn55 - Did you get the Meyle coffin arms or the Meyle wishbone/tuning forks? I can find the Meyle coffin arms (Meyle P/N [phone removed] Porsche P/N 996-341-053-17) in the US, but not the tuning fork (Meyle P/N [phone removed] Porsche P/N 996-341-043-06). Design911 in the UK have a kit consisting of two of each and hardware for $455.40 shipped to the US (actually cheaper than buying the UK because we are not charged VAT). I may just go off and get that kit because the more I think about it, the more I think doing the drop link on the passenger side that I've not replaced this weekend, then doing the rest including the control arms once I have them all since I'll need to get an alignment. Of course if I do that, should I do the shocks and the rear bushings as well, i.e. ejdoherty911's suggestion... Decisions, decisions.

If it sounds like metal slapping. It's your upper strut mounts. Only way to determine it is to remove the strut assembly. There's a rubber bushing in that tears and causes the strut to slap around.

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You're quite wrong. Although it does look somewhat like a rubber bushing from outside, that's just a rubber boot covering the ball joint. Enjoy: You Tube

.. best thing to do as previously mentioned is to lift the front end of the car and check for play. Don't forget to grab hold a shock and check for play (upper strut mount). On the 986 Boxster the wheel bearings fail (alot), and the 996 shares the same front hub/wheel bearing design as the Boxster (2wd 996 only). Also the sway bar bushings are usually what we change first as they're inexpensive, easy to change, and you will be replacing them at some point so its a good one to cross off the list first. https://rennpart.com/carrera/carrera...onents-street/

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You're right... I priced this out (you can see this here ). I looked at three scenarios for the front and rear, all bushings, control arms, shocks, springs, etc: Genuine parts: $6800 (priced at Sunset Porsche Parts, so less than MSRP) Aftermarket and some Porsche parts where I couldn't find substitutes: $4650 Aftermarket and M030 kit, which means M030 shocks, springs and sway bars and aftermarket other parts: $4300 Seems to me that the way to go for doing a suspension refresh if you're not going to massively upgrade parts with adjustable control arms, coilovers, etc. is the Aftermarket and M030 approach.

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I stand corrected - I had forgotten about that video! I can say, the EPS arms perform extremely well - much better than the stock arms that were on it (that were worn out). Unfortunately, I can't comment on how they compare to new stock arms... Thanks for the clarification! 👍

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Thanks for this. I'll know more when I get it up on the lift tomorrow and take a good look and give it a good shake. I spun the wheels and didn't think they sounded bad but I read someone else saying that they had a bad bearing that didn't really exhibit much in the way of symptoms. I notice on your website that you have transverse control arms (coffin arms). Are these the OCAP ones and if so, how have you found the quality?

Spent some time poking around. I found the driver side sway bar link broken! I had replaced this about a month ago. Strange. The passenger side sway bar link seems to be shot and there’s play in the sway bar bushings. Wiggled the shocks but no apparent play in the strut mount. Wiggled the control arms as well but I didn’t find play. So my plan is to replace both sway bar links and the sway bar bushings and then take it from there.

This weekend's project is to replace the drop links and the front sway bar bushings. Lemfoerder apparently didn't want to know about doing a warranty replacement on the snapped drop link because it was bent, even though it looks like the weld is what went. Kudos to the local shop that I bought it from for providing me with a new part free of charge. This one is a TRW.

Drop links and sway bar bushing replaced. Knocking not completely gone, but not as pronounced. Video of how to get at the front sway bar bushings if anyone is interested. You Tube