Car feels jittery and floaty, 06 Cayman S

For the last couple of weeks my 06 cayman S feels jittery and floaty, on higher speed i hardly can control the car, seems its going to fly off the road. on low speed seems rocking side to side. took it to the shop they did alignment and that didn't help, they checked the suspension and said nothing is wrong, went back to shop again today they couldn't find anything, they tell me its my front Tires . and his explanation is since the front has more tread than the rear thats causing the car rock side to side, her is the picture of the front and rear tires . .

Are those even the same tires front and rear?

yes, they are. michelin pilot,been on the car for over 2 years. never had this problem. seems like something is loose. but they check the whole suspension.

Those look like different tires on the front - looks like Pilot sport AS3. Rears look like Pilot Super Sport. But different tires by themselves shouldn't cause side to side slippage ...

Whoa....looks like you have Supersports mixed with all seasons. I would change to SS's ASAP, very dangerous especially if it rains. I cant believe the shop thought that was ok!

Maybe a bad shock.. Only thing aside from tires that would typically change so drastically. Did this come on all of the sudden?

Looks like you have two completely different types of tires (high perf vs all-season) on the car, and you also have a large difference in tread depth between the front and rear too. Either of those issues can cause some pretty noticeable handling problems. In your case the softer tread and sidewalls of the fronts are probably allowing the front of the car to wallow back and forth while the short tread and stiffer sidewalls of the rears are keeping the rear of the car stable. Actually kind of dangerous to mix tires like that and certainly not approved by any car mfg to do that kind of thing. Match your tires up front and rear and you should see a large difference in how it feels.

You state that the mixed tires have been on the car a long time and this issue just started, so IMO it's probably not related to that (though still not the best idea, as others have pointed out). Have you changed anything, or had anything happen that coincides with the onset of the symptoms? I'm surprised that the shop found nothing with the suspension - it would be my guess. I would think either a shock has failed (no more damping at one corner), or you have a loose connection in the suspension. My suggestion: 1. Jack up each side of the car and give the wheels a good shake in all directions to see if you find any looseness. You might get lucky and find the culprit (though the force you can apply with your hands is pretty small compared to the forces while driving, so may not be enough to move something that is loose). 2. Bounce each corner of the car to see if one corner wants to keep bouncing more than the others (failed shock). 3. Check all of the suspension bolts yourself. I once had a lower control arm bolt work loose on my car and it created symptoms a bit like you describe. I couldn't find anything physically wrong and raced on it (!), but it was later found with the car up in the air. It's not obvious something is loose unless you physically check all of the bolts. It's scary to have a car misbehaving and not know the cause. Be diligent identifying what's going on. And I wouldn't suggest racing on it...just sayin'. Good Luck..

When you have the car jacked up, grab a tire at 9 & 3 o'clock and see if you can wiggle it. If you have excessive play, you have a bad wheel bearing.

How reliable is your shop at doing the suspension geometry? Toe out on the rear or excessive toe out on the front is likely to cause your symptoms.

Can you post your alignment sheet or specs? Sent from my iPad using Tapatalk

Thank you all for the reply, As mentioned tires been on the car for more than 2 years and i never had any problem, shop checked the suspention, they said everything's fine, all i need is new tires , They said it didnt even need any alignment. personally i dont think this has anything to do with tires .

Let us know when you solve it...

I don't know if you are right but if you are, it's hard to believe that any tire shop would mix all seasons with Supersports. The shop mounting the tires could be culpable should an accident occur. Hence, every shop that I've ever used is hyper sensitive to mixing tires . In my case I always replaced four tires on my 911s , even though there was more than enough tread on the fronts to justify not replacing them. Four new tires and an expert alignment were well worth the expense to me, since they replicated the handling that I enjoyed when the car was new. In effect it was almost like having a new car.

If your shop thinks mixing tires like that is OK I would be suspicious of any suspension work or diagnosis as well. It's not OK on these types of cars. The compound, design and handling are all very different. They may have been on the car for a while but as they wear the problems would be compounded and exaggerated. My money is on the tires as the cause. Keep us posted.:cheers:

If it's not tires , suspension, or alignment then... I'd get the tires sorted anyway, then get a second opinion from a shop or dealer that is familiar with the car model. Sent from my iPad using Tapatalk

I'd take it for a second opinion. One thing I would mention, is that you should make sure you're running the correct tire pressure (I know this sounds like a no brainier) and check your rims. Many shops over-fill tires without consideration...have had this happen several times, and the car feels vague, has piss poor traction, and almost feels 'stilty'. I would also feel around the edges for any bends or lost wheel weights on your rims...that would give u symptoms like this. Over inflating masks wheel imperfections/balance like that too. But for future reference, like all the guys have said, don't mix AS and Summer tires ....your just gonna get funky driving characteristics. Good luck.

The shop that i take my car is reputable shop, they only work on Porsche , Ferrari, Maserati, they checked the suspension and couldn't find anything wrong. they did not install the tires . as mentioned they been on the car for over 2 years and i never had any problem. they told me to change the tires . im going to order the tires and see if it will fix the problem, What is the best tires i can get for the car?

Hey, after this thread goes through the "What are the best tires ?" evolution, can we turn it into an oil thread? :gossip: Most definitely the wear in tires can contribute to poor handling. On a motorcycle, every suspension and tire change is magnified. It seems to take longer to notice things in a car. I can tell when my bike tires are getting out of round, or hard rubber, to down to the cord. Lots of people don't notice in a car until things are really out of spec. Recommendations for tires are dependent on where you live, how you drive, what your expectations are for tire life, what your relative values are for safety versus handling, etc. It's like saying "What is the best food?", "what is the best sport?" I just bought my Cayman S , and it had Michelin Pilot Super Sports on it. That seems to be what the universal consensus is for these cars, in a summer environment. Except, mine were from 2008 in 2016. I ditched them even with 50% tread life remaining. I probably should have done some Clorox burnout videos with them, but didn't want to be one of those clowns who roasts a clutch on video. I replaced the Michelin PSS with Yokohama AdvanSport performance all seasons. My rationale is that even my "summer" tires on my Volvo are Bridgestone Potenza AS970s, since in the mountains we may hit slush, mud or stone at any time of the year. I was going to go with the same on the Cayman , but the Yokohamas got better ratings for handling and road noise than the Potenzas, and were cheaper. So I experimented. Any four matched, quality tires will be better than unmatched, worn, mystery tires .

blacksea have you changed your absorbers before? if you haven't thats the first place I'd start. I recently changed mine and it did a world of difference.

The Yokohama AdvanSports are a great street tire. Smooth and quiet ride. As mentioned by RH, dampers are your most likely culprit.

Why is this thread starting to feel like a troll...

Just ordered Michelin pilot sport PS2, i should have it tomorrow, i will post after they install the tires . i hope this is going to fix it if not i just spent over $1100 plus installation for nothing. [h=2][/h]

Well, it isn't "for nothing." You now have proper tires for a car that exceeds the velocity and roadholding capabilities of the majority of vehicles. As they say, before you can start going faster, you need to make sure your vehicle is "Stage Zero." All systems working as new from the factory. Proper tires in a known-good condition are a major part of that. If this doesn't fix it, you've ruled out the most likely starting point, and can move forward systematically. If you just want to bodge things together with duct tape, you could be driving a used Subaru BRZ for much less.

I'm still suspicious of the alignment. If the tires make it better but there are hints of he problem when they are cold in the wet then it may not be as good as your current shop suggests. I'd spend the $250 or so to have it done preventatively and then you also get a fancy sheet that shows you what it is. Thinking of it as insurance as that can cause excessive tire wear. Sent from my iPad using Tapatalk

OP said he had the car aligned, and that the shop routinely works on Porsche as well as other high-end cars suggesting that they ought to know how to align the car. The shop also told him that the problem was the front tires, which several here have agreed with. If there really is no damage or wear to the suspension components, and the alignment is correct, it really must be the tires. Let's hope the new PS2s do the trick.

PROBLEM SOLVED, Thank you All for the respond, shop installed the new tires , that solved the problem, i honestly wouldn't think it would be from front tires since they were practically new, they said the rear tires were dry and front had more tread on it and was acting like spring and was making the car jump around.

Glad it worked out for you and pretty happy some of us nailed it for you right away. Happy motoring.

Glad you solved it. There is a very good knowledge base in this board. I am constantly learning things here.:cheers:

looks like I wasn't the only one to spend time in the tyre shop this week. glad you're able to enjoy your car once again. Only thing I hate about new tyres is breaking them in

I realize this is an old thread but I have n 06 Boxster S and am having the same issues. I have Mich Pilot super Sport tires on front and rear so not mixed BUT I noticed that the thread pattern and thread depth is very different from the front to rear tires . (Contacted Michelin directly) Apparently Mich changed the design, pattern ect on the Pilot super sports. My newer front tires look like a totally different tire!! The fronts look like an all season compared to the rear tires which are the older design and look very similar to the old PS2,s. I have 140000 kilometres (approx 90 k) on the car so probably most of the suspension parts need to be replaced and thats not helping matters. But the car acted exactly as per the original posters remarks. Wondering,loose feeling on hwy not the typical tight feeling. The rear tires are getting down on tread also.Unfortunately Mischelin stated that the tread pattern will not be the same as the tires are different sizes front to rear and the rears dont come in that design.WTF! Has anyone else had this issue. Looks like I need to get a different rear tire (not the PPSS)