Anyone have any idea what could cause these two things?

Hello all. So, I'm having two unrelated issues that are bothering me a little with my Cayman S at the moment. If anyone could help out it would be greatly appreciated. The first, and more serious concern, is that the car suddenly seems to have developed a tendency to wander at highway speeds and change direction unexpectedly under hard braking and acceleration. I first noticed it last weekend while I was on a 2 hour highway drive. I was starting to think "Man it got really windy all of a sudden", as the car suddenly seemed to be a little all over the place in the lane. Then I stopped to get gas, and it's perfectly calm outside. Back in the car, and the same feeling is still there. The car just seems to have a mind of it's own, and doesn't want to go straight as it has in the past. I'm not really feeling any tug on the steering wheel, the car just changes direction slightly, and it seems to be in a virtually constant state of change in direction. It's subtle, but quite noticeable. I have also noticed the car moving around under hard acceleration and braking. Under acceleration, the car seems to lurch to one side or the other when you release the gas to shift gears from 1st to 2nd for example. I am thinking I may be correcting for a pull that then disappears when power is removed, causing the car to lurch to one side. I need to pay more attention to which way it is pulling next time I get a chance. Under heavy braking it does something similar. It's not 100% consistently there either, which is odd. These issues feel slightly similar to an issue I had with an old BMW 540i. In that case it turned out to be rear ball joints, but I don't think this suspension has a similar item? In any case, advice would be appreciated. The other issue is a minor annoyance. The driver's seat has started clicking back and forth under acceleration and braking. It feels like there is some slop in the for-aft adjustment mechanism, and you can both feel and hear a slight movement of the whole seat. Quite annoying, as I am very sensitive to such things. I don't suppose there is a way to adjust a tension or something along those lines? Any and all help would be appreciated.

If I were in your shoes, I would go to a good tire/alignment shop preferably those who have experience in racing cars. As for something I could do myself tire would be check tire pressures, check for any deformation on the tires like from hitting something, check the wheel lug nuts, check if I warped the wheel. If after alignment problem is still not gone I would think the steering rack would be something to get looked at then. As for the seat I would probably go to the dealer haha. I don't think there are any adjustments obvious to me for that! Hope that helped! Good luck!

Agree with getting the tires and alignment checked. On the seat, the sliders are secured with 4 bolts. You'll need an E12 torx socket to tighten them if they are loose. There is a plastic cover on each side in the front and the rear bolts are exposed if you move the seat all the way forward. Are they manual seats? There are pins that are released when you pull up on the adjuster handle and they should firmly engage when the handle is released. You might try moving the seat a bit each way and be sure the pins are engaged. Not sure about power seats. Best of luck.

It's probably not the seat bolts connecting to the floor...it's movement in the rails themselves. There were numerous posts on this a few years back, and a couple of folks got new rails under warranty, only to have the problem return. It's been evident on our 2012 CS from new, and two attempts by the dealer to fix were unsuccessful. It used to bug the heck out of me...now I don't notice it. BTW, my 2011 Carrera GTS does it too with the Sport Seats...but the GT2 seats I had (sold them a few months ago) were rock solid.

They are power seats, so I'm guessing they are worm gear driven, but I really don't know for sure. I get the distinct impression that the seat is sliding within the rails, rather than the whole assembly shifting, but it's hard to say for sure. I can remedy it by pushing the seat back against the firewall, but that is not the most comfortable seating position for me, as the steering wheel ends up right under my knees. On the wandering issue, I'm not inclined to get an alignment done just to see if it fixes things, as it's an expensive troubleshooting step. The wheels and tires seem ok, and there is only an occasional slight shimmy when the car has been sitting for a while and not yet warmed up, as if the tires are flat-spotting slightly then rounding out and going back to smooth. It feels like it has to be a suspension issue of some variety, and the best an alignment could do is find a damaged part, which would result in paying for an alignment twice, since I will not pay a shop to replace anything suspension related unless it is warranty work, since I can easily do it myself.

I believe if it was an alignment problem the car would exhibit consistent tracking pattern, which seems not to be your case. If I was you I would get under the car and carefully inspect all suspension components for damage or wear out. As you mentioned in your BMW example and from experience I know that even very small things can change the road behavior of these cars. I would start with ball joints, steering arms or stabilizer joints. Of course the steering rack is also a possibility and I hope that is not your problem.

jack up the front of the car and grab the tire at 9 and 3 o'clock and check for play, then do the same at 12 and 6 o'clock. Good visual here: https://www.yourmechanic.com/article/how-to-check-a-front-end-assembly

You are most likely correct...it's probably loose rivets in the seat frame that attaches to the rails. Here's a good discussion on the issue from a few years back. http://www.planet-9.com/987-cayman-...-and-complaints/31188-loose-seat-am-i-being-too-precious-3.html?highlight=seats

Bad wheel bearings had occurred to me, but I have not had a chance to check. No jack around at the moment, as this car doesn't come with one. I have not had any of the normal audible effects of a wheel bearing though. Will check them when I get the chance. I also get an impression that this issue is actually coming from the rear of the car. Mainly because there does not seem to be any play in the steering or anything of that nature, and the whole car seems to wander, not the front end, if that makes sense. It feels like I am correcting a rear wheel steer situation. Thank you, gcurnew. That is actually a very helpful thread. Unfortunately I have zero faith that the problem would be rectified if I take it to my dealership. They would almost certainly keep the car for three days, tell me it's "normal" (as they did with the horrible radio reception that turned out to be a bad radio amplifier) and charge me $195 for the privilege as my extended warranty does not cover troubleshooting. I'm certainly not going to pay $950 out of pocket to replace the seat rail assembly either, especially as it would just go bad again from the sound of things.

If your car was an M3 , I'd say your car's rear trailing arm bushings are worn out. Your symptoms are textbook. I don't know as much about Porsche rear suspensions, but I'm guessing the problem involves some worn out suspension parts, not an alignment issue.

That was my first thought too, but like you, I''m coming from the BMW world and don't yet know much about the Porsche Suspension design. I really wish I could find a site like RealOEM, but for Porsche .

If the problem has been coming on for some time, I would begin to suspect the tires . The symptoms you describe sound a lot like a problem someone posted about (on a different forum). All of the same suggestions and suspected problems that others have already made here were also proposed in that thread. It turns out that the tires were 100% to blame in that case despite the fact that they had plenty of tread and that there were no signs of mid-alignment. I realize that this is just another suggestion regarding the problem, but if you begin to rule out alignment, suspension wear or damage, etc. you might find a new set of tires is the solution.

The problem seems to have been a pretty sudden thing. I drove it one day with nothing to complain about. Next day it was acting weird. The tires are getting up there in age and I had intended to replace them in the spring anyway. Waiting until after a home purchase here, as I am pretty sure I will need my spending cash when that happens to correct lots of little things.

So I drove the car home to PA and back this weekend, and the wandering problem seems to be getting slightly worse. On freshly paved highway, you could feel a thrumming sort of vibration. It comes through the steering wheel slightly, but you feel it more strongly through the seat of your pants, and when I had a drink in the cup holder you could see it vibrating. It's not a completely consistent vibration, coming and going in intensity and speed, even while speed and road surface are constant. It actually reminded me slightly of a bad wheel on a shopping cart, it has a similar sort of inconsistent pattern to the vibration. The wandering aspect of it seems to be tied more to road surface though, as I guess it is following slight cambers in the road surface. It is particularly noticeable when you change lanes over a transition or the like, and seems to be more noticeable on the right side of the vehicle, as in when the right wheels pass over a transition, the car jumps much more noticeably. It has me thinking bearings, but I;ve never seen one do anything like this before.

Maybe you've had a belt shift in the tire.

Definitely sounds like a tire or alignment issue. Kevin

It still sounds like tires to me, but I would also suspect the alignment as well. Have you tried varying the tire pressures to see how that changes the feel of the car? Driven over the same roads, I can tell when the tire pressure is too high vs when it is close to or at the recommended pressures. One of the symptoms is road "noise" can actually be felt through he steering wheel and even through the seat of the pants. Also, if you are feeling a wobbling or vibration at speed, you may have a bent wheel, a damaged or deteriorating tire (such as a belt slip as suggested above), or simply a wheel/tire that needs balancing.

I'm gonna guess your inner tie rods are worn. They are tested with front end off ground, steering wheel held, checking for play with hands at 9 and 3 o'clock as alluded to in an earlier post. The inner tire rods are a wear item, and they won't make noise when failing. Mine were showing some wear at 30K miles on my 06 CS. PS I wouldn't be driving the car at speed without getting it checked and fixed. Sounds dangerous. Hope you let us know what you find.

I'm hoping to get over to the garage tonight to take a look. I need to get myself a floor jack , but at the moment I am in a second floor apartment and not too keen on the thought of lugging one up and down the stairs, not to mention where to use it. I have an offer in a place with a garage, so hoping to hear something shortly on that front. In the mean time I take my car to the Auto Craft Center on base and use their facilities. As far as the inner tie rod, would that be part #6 on this diagram? Also, what would be the best method for checking such a part for wear? I'm guessing it's inside the boot?

Update. Had the car into the specialist, and while they did find a few issues, it seems that the steering rack is ok. The biggest two problems they found were the front control arms, and a wheel that was out of balance. They said there was some evidence of movement on one side in the control arm. Turns out, that is actually a nice little bonus for me though. They were able to get both control arms covered under my extended warranty, and came up with a very welcome suggestion. They offered to upgrade to the GT3 control arms for the difference in cost from stock, which happens to be $200. They also found a bad motor mount and replaced it. So, all told I will be getting new GT3 Control arms, a performance alignment to take advantage of them, a wheel rebalanced, and a new motor mount installed, for $200. Chaching!!! That $50 to transfer the extended warranty the previous owner bought was the best investment I ever made.

thats great that the warranty covers the work needed. the warranties in my country don't usually cover wear and tear items. the upgrade is nice - its a slippery slope as then you may need rear adjustable as well

Under my warranty, the control arms are not considered a wear item, thankfully. Things like brakes and the clutch assembly are wear items, but all suspension parts are covered. It's a "bumper to bumper" extended warranty, and is the company's "platinum" option, so it is probably better than most. It does not cover things that are considered "cosmetic" though, so I was on my own when the headliner fell down on my head. I would think that would constitute a safety hazard rather than a "cosmetic" issue, but they did not agree. Currently waiting on an upholstery specialist to finish wrapping the headliner in alcantara to correct that issue. As far as the slippery slope, you are preaching to the choir there. I was already going to be headed down that path to some degree, this just saved me a lot of money on something I was already planning for. I'm going to wait until next summer most likely, but I plan to do a full coilover install, exhaust , tune, and most likely a plenum. I know the plenum most likely will not gain much power, but if it eliminates the weirdness of the factory one, that would be worth it in my book. I'm not a fan of the stepped power delivery, and would prefer smooth delivery, even if it may not have quite as much torque at some RPMs. One other update, when I picked up the car from the specialist, they pointed out that they had found one of the front wheels to be just slightly out of balance. They corrected that, and it fixed the shimmy the car had developed, but the wandering feeling is still there. Hopefully the control arm replacement will take care of that when they come in. They also already replaced the engine mount, and that made a very noticeable improvement in clutch engagement. I had been getting a little judder on clutch engagement, and figured it was getting close to time to replace the clutch. That judder is gone now, but it probably still needs a new clutch soon. The clutch take-up is still inconsistent, occasionally suddenly locking up and stalling the car(especially on humid days for some reason), and also sometimes feeling like it has no grip for a moment and allowing the engine to rev higher than expected. Makes me feel like I forgot how to drive a manual.

Another Update. The car was in and got the GT3 Control arms installed and an alignment this past Thursday and Friday. I had them check a few other things, as my extended warranty is coming to the end of it's term in late October. The long and short of things is that the control arms were part of the problem, but not the main source. There had been some vibration in the steering wheel before. I had assumed it was due to tire wear, as the current MPSS tires are nearing the end of their service life, but that vibration is now completely gone. The front end now feels rock solid, but the strange wandering sensation is still there. If anything, it may be worse than before. With the front feeling so solid now, I strongly suspect the rear axle is where the problem lies. On that note, the alignment of the car revealed that the rear toe was off by 3° on one side prior to alignment. That's pretty huge, and makes me now suspect that something may be actually moving in the rear suspension that affects the toe settings. The problem with the car now almost feels like the car is wagging it's back end around, and you feel it more in your butt than anything. There is no tug on the steering wheel that I can distinguish. So, the car will be going back in this week to have the shop go over the rear axle with a fine toothed comb. Hopefully they can find the problem and take care of it prior to the 25th. Edit: So I just spoke to the show owner on the phone to set up the appointment. He strongly suspects that I have a blown rear shock after listening to the symptoms and knowing what has been ruled out.

Another update. It turns out the entire factory suspension is shot at 60K miles. All 4 shocks, bump stops, and mounts are worn out. The ride is steadily declining at this point. It seems worse every time I drive the car. My shop is going to talk to the warranty company tomorrow, and there is a good chance I end up with a little over 2K to play with for replacement, as that is the cost to replace the factory components. Bilstein PSS9 is a strong contender for replacement. Anyone have any other suggestions for what I should look at?

Just trying to understand what you are saying is wrong with the car. Are you saying that the shock units are worn out along with the shock mounts? When you say the whole suspension is shot, do you meant other components in addition to the shocks? I'm not sure what bump stops are on a Cayman, but on other vehicles they don't seem to be something that can really wear out.....gotta look into what that is I guess.... Assuming you haven't owned the car since new, what do you know about the prior use of the car? Everything being worn out at 60K miles seems unusual and I am curious as to how the car was used that would lead to such worn components relatively early. Your saga has been interesting to follow. It seems like you're finding out about worn components one at a time making me wonder why the shop(s) have not seen the problems from the beginning??

don't be surprised if the shocks are gone. your car is about 8-10 years old and sounds like the roads must have been challenging to be driven on. in your case the guys who did the alignment or changed your arms should have spotted it or noticed the debris from the bump stops. change all 4 corners. on my car I replaced the entire set at 65k kilometres (about 40k miles). My indy noticed the bump stop condition during an alignment as the first sign the shocks were worn out. I had to change a bunch of items on the handling front to get the car to the level I wanted. (5 arms, 2 mounts, strut bearings, full set of absorbers as at current count) It also helped balance out the issues with ride and handling on the 19's. (past due absorbers tend to handle bumps differently) Check out my past thread to see what the bump stops look like and what I chose to replace them. http://www.planet-9.com/987-cayman-and-boxster-chat/146937-bumpy-journey-changing-absorbers.html hang in there feeshta, soon you'll be out cornering those WRXs

I'm not really sure why they missed the issues the first time around. Most likely because the over-focused on the steering wheel vibration issue, which did turn out to be caused by the front control arms. Would have been simpler if they had found it the first time, but the important thing is that they did find it this time. Which other parts have you changed on your car at this point? I would guess lower control arms, but not sure what else there might be. Rubber dry rots with age, so the mounts may simply be going through the effects of that. In any case, it is a part that is normally replaced along with the shocks, as they are a wear item and it only makes sense. It simplifies the install as well, as you can assemble the shocks completely prior to performing the work, rather than having to pull the original shocks apart with a spring compressor etc. The bump stops seem more like foam than rubber to the touch, and spoiled foam at that. I think it is a combination of age and abuse that caused them to fail. From here I just have to hope the warranty folks don't make the process too much of a pain in the ***. Once they do authorize the work, I just have to choose what to replace the factory parts with. I'm currently leaning towards Bilstein PSS9's, with MCS an outside possibility if the price guesstimate the shop gave me is actually true. They seemed to think I might be able to get into them for only a few hundred out of pocket, but I find that hard to believe given their list price is over 4 grand, since they don't make the cheaper options for our cars for some reason. If anyone else has any other suggestions, I would be open to them. I don't want to lower the car much at all, as it already has some issues with scraping on transitions at the factory ride height. I've never been able to tell whether it is the front end or those little plastic wheel spoilers or whatever they are called. Didn't see much scraping on the front lip when I had the car on the lift, so I suspect the later. I really wish Ohlins had a Road and Track kit for this car. It was brilliant on my old BMW and I would happily go that route again if it were possible.

feeshta, important to get the entire set of arms, bushes, mounts, bearings checked out. the total repairs can only be determined once a thorough visual and physical check is done. other than arms, other items could include trailing link arms, front and rear suspension mounts (the ones with the foam padding at the top of the struts), front strut bearings. These are some of the items on my list. the absorber struts are the pivotal point for each of the corners and changing them will make the big difference. In your case, because you have specific needs in terms of handling and setup. each item may need to be considered toward your end game in mind as to which work well best together. some may not need replacements as they could be part of the PSS9/coilover setup you plan on having. most of my adventures are in the following threads: http://www.planet-9.com/987-cayman-...nd-boxster-service-and-tech/91184-front-lower-control-arm-ball-joints-done.html http://www.planet-9.com/987-cayman-and-boxster-chat/146937-bumpy-journey-changing-absorbers.html