Nagging Issue When Turning

Greetings from Nashville, I was hoping to get some thoughts about an issue I have been having for almost a year. I have a vibration that started in the right rear wheel area when turning right. It feels like when a tire rubs the inside of the fender or ABS pulsing, and it makes a groaning noise similar to a wheel bearing. I have taken it to the dealer 5 times, and they have done the following (it's an 08 6 speed Cayman S): Put another set of rims and tires on it Removed the ABS fuse Checked bolt torque and movement in suspension bits etc Swapped the transmission mounts Aligned it Put chassis ears on it They initially thought it was a CV joint or wheel bearing. Now they are going to replace the transmission fluid and look for metal bits in what they drain. It has started doing the same thing when turning to the left now as well. I notice it most when going into long high speed sweeping curves or pulling out of my office onto the main roads and turning tight while giving it a decent amount of throttle. If I drive it without dipping into the throttle I don't notice it, so I would presume it is more g-force induced. Sometimes when I feel the vibration, it feels like it moves across the axle from right to left. Some other things I have noticed which may or may not be related are: Going down a short steep hill at the office either braking or just letting off the throttle, there is a popping noise when the car starts to decelerate. Sometimes when I leave the house at the first or second stop sign I get to, there is a thud that you can feel and hear in the back when accelerating from the stop sign. There is a back road with rumble strips on it before a stop sign, and when I go over it, there is a hollow feeling vibration. Does this turn on a light bulb for anyone? I am worried they are going to tell me the transmission needs to be replaced, but I can't see how it could be causing the issue unless it's the diff they are worried about. Any help or reassurances to make me feel better would be appreciated.

My guess would be CV joint, esp with the noise on deceleration and turning. Are the CV boots good? If there's a tear, water will get into the joint and will wash the grease out of the it. It might be coincidence that both of them fail simultaneously, but it is possible. There aren't a lot of reports of failed CV joints, but if the boots are torn they'll fail. What made them decide it wasn't the CV joint? Are they taking you for a ride on all the other things they're changing? If they are charging you for all this stuff, I'd be suspicious of them. Changing the trans fluid doesn't fit the symptoms. I'd make them the following ultimatum: change whatever you want, but if it doesn't solve the problem, it's on their dime not yours. Bet they'd find the problem a lot faster.

Have them check the power steering rack and look for a fluid leak. Had similar experience with my 2008 base Cayman. Cured my problem. Hope this gives you something else to check before a major expense.

Thanks for responding! They have actually been great to deal with, and they haven't charged me for all the stuff they have done including the fluid change. When all of this started, my buddy and I jacked it up and tried to wiggle the wheel as well as inspect the boots. Nothing seemed amiss, and the dealer inspected them as well. I am not sure what made them start focusing on the transmission, but he said if the fluid was too thin or thick it would make a noise. I don't know how that equates to the vibration though, and he was not able to answer that. It may be a grasping at straws issue at this point. I should know more tomorrow after they change the fluid. I have a feeling I am going to have to start throwing parts at it, and hope something works.

Thanks for the thoughts. Did you have issues in the rear?

Motor mounts? Worth a check.

I thought is was a strut or wheel bearing in the left rear and right front. Would have bet money on it. Hendrick Porsche said it was the power steering rack and they were right on. Good luck

Looks like it probably is the motor mount. They called and said the cover fell off when they removed a panel or something to that effect. I should know for sure on Monday I suppose. Thanks everyone!