While driving vehicle, noticed some slippage/clunking when turning. Took vehicle to Porsche dealer, they said transfer case needed to be replaced. Car has 12,600 original miles on it. Dealer said there was an extended warranty on the transfer case that had expired. In researching, it became obvious that there is a Porsche design problem that affected several model years for the Cayenne. As a mechanical engineer I am concerned that a transfer case failure at freeway speeds could be dangerous. Separately an auto mechanic shop opined that driving without replacing could be a safety concern. In my opinion there should have been a recall rather than a extended warranty.

- Homewood, AL, USA

At slow speed, under acceleration, the transfer case slips, and makes a thumping noise. Over time, the car has poor acceleration when trying to get up to speed with other cars. The dealer has confirmed that this is a problem with Porsche Cayennes. Thank you.

- Davis, CA, USA

When slowing almost to a stop, and then need to accelerate, such as slowing for a yield sign, then trying to merge, vehicle is non responsive to throttle input for at least a second, or more. This has put me and others at risk because I assume I'm going to be able to accelerate when pull into traffic and am not able to. The dealer has had the vehicle but was unable to reproduce. It does not always do it, there's some combination of engine, drivetrain or fuel management it's in that does this. I have disabled start/stop mode. There are no system messages or OBD errors. The dealer has said that others have experienced this and the manufacturer has told them it's "normal". It's a safety problem and I'm seeking help in getting the manufacturer to fix it. Note, I sent the attached letter to manufacturer and did not receive a reply. I called their customer support line around Sept 20th and they did not offer any escalation or other action to address other than writing to their email address. I did this, and received no response.

- Saint Louis, MO, USA

42,000 miles on the 2016 Cayenne gts. $110,000 original sticker. Transfer case needed to be replaced ($5,000+ charge). Service rep told me they replace 5 transfer cases each week at just their dealership. Clearly a defect that should be subject to recall. He knew in 5 seconds what the problem was when I originally called to schedule an appointment. Porsche usa refused to take responsibility for the cost of repair. Warranty expired 5/31/19. Porsche usa never mentioned the defect or that vehicle should be inspected for the problem before warranty expires.

- Newtown Square, PA, USA

Vibration from vehicle causes ear damage to occupants, whether vehicle is stationary or moving.

- Woodbury, NY, USA

Car lost all acceleration and engine shut completely off happens frequently. Car on separate occasion sieved and shook violently to a stop on the road multiple times.

- El Paso, TX, USA

Last week I had my car for 20000 mile service and the technician noticed vibration with acceleration and advised the transfer case be replaced which was done 10/28. I contacted Porsche usa as I was concerned with this being a relatively new vehicle and the problem with transfer case so fast.I was told it was a manufacturing defect and the transfer case was replaced with a re manufactured one and not a new one. When I wrote to them I was contacted today and told that was not a possibility. This being a relatively new well maintained vehicle and this being a manufacturing defect I prefer a new transfer case and extended warranty. I believe that is very reasonable. Can you please look into the matter and advise

- Crisfield, MD, USA