jan86

Hello all,
i read many forums about PDK clunk sound mainly from 2nd to 1st and from 1st to 2nd. I experienced it myself sometimes (not always) from 2nd to 1st stop and rarely from 1st to 2nd. When i visited dealer they said its normal lots of owners ask about it nothing wrong. Still i let them during oil and spark plugs service make change oils and filter of PDK and make calibration of PDK. So after that i felt it better but know honestly i thing its only psychological illusion. I owned lot of nice cars but 911 its like rolex and im too obsessed and sensitive to any strange sound etc.

So after couple months of playing with car i figured out how to summon these clunks and how to avoid it and get rid of it.

You can test it by yourself (preferably at night when it's quiet during daytime traffic and you don't have to hear anything)

How to summon clunk PDK downshift from 2nd to 1st
Most significant in manual sport mode drive in 2nd gear and slow down by let of gas and don't use brake or very lightly braking until car with downshift to 1st itself u have chance to hear clunk noise. As the slow down is longer more fluent bigger chance to get clunk. It can also happen in manual mode normal and also automatic mode sport. In automatic mode normal not happen or very rarely.

How to summon clunk PDK upshift from 1st to 2nd
Most significant in manual sport mode drive in 1st gear with very light gas "feathering gas" to 1500 - 1900rpm hold that rpm with very light gas for 1-2s change 2nd have chance to hear clunk noise. It can also happen in manual normal mode rarely in automatic sport mode. Never happen in automatic normal mode.

How to avoid clunk PDK downshift from 2nd to 1st
Use the brake more when u slow down to almost stop do not feather braking pedal. If you are in manual mode you drive in 3rd lights or bump coming start braking and downshift to 2nd while breaking still on brake and let car itself downshift to 1st. Sometimes there can still be hear little clunk but barely noticeable. Second solution is down shift to 1st by self at higher rpm but it can be uncomfortable. Most simple is when u slowing down use brake more firm.

How to avoid clunk PDK upshift from 2nd to 1st
Do not be to light "feather" on gas while start moving from 1st do not hold it don't hesitate just give some gas at least 10-15% to feel some torque it can be 2500 - 3000rpm shift point or higher it never clunk. Also in automatic normal mode even if you are so light on gas it will not clunk it shift very soon very high gears.

Execption automatic normal mode - if you drive car like limo with light foot without clear signs if you are accelerating or slowing down it can cause these clunk noise at low speeds.

My theory about upshift from 1st is too little gas can make low pressure or ecu is not sure if u will stop again or upshift insufficient signal for car with too light gas same about down shift from 2nd slowing down too light and too long that ecu may prepared for again accelerate and prepared for 3rd than have to suddenly go to 1st. Don't be like me too ocd to finding defects which do not even exist just enjoy car and repair if it really broken. I read so many post when owners experience this on brand new cars so its normal nothing to worry about it same told me two porsche mechanics if somebody talking i never experience it they are minority and may have different driving style play music not paying attention not be too sensitive. Hope helps somebody sorry for my english

You can watch video of PDK calibration where is clunking noise on every gear selection while car stand still shifting thru gears and calibrate yourself. Time 11:29