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I appreciate your advice. I did agree with you from the beginning that the problem is most likely the distance sensor, but hey, when we found out it worked again after a recalibration, as a computer geek, I have to play around with that to see if I can find a pattern there! Don't worry though, the distance sensor will get replaced soon, and again thanks for your input.
As for the speed sensor, I think I will roll my dice, doesn't seem to be as common of a problem compared to the distance sensor, and I'm willing to take my chance here to save a thousand dollars.
Again, thanks for your time, input, and contribution, not just to my particular problem but to this whole PDK failure scene in general.
You are welcome! Happy to help.
@byroncheung I'm going to make an observation that many here may find offensive but please keep in mind that it's in the spirit of curiosity rather than judgment.
It absolutely blows me away that an affluent owner of an expensive car (Yes; All Porsche owners are affluent. Relatively speaking.) views preventative maintenance as a waste of money. If you know there's a failure rate of any kind why would you not spend $1200 on a speed sensor while you're there to prevent a possible future breakdown and additional labor down the road? As a shop owner, racer, boater and someone who finds tremendous value in my time, I'm truly confused as to what drives this type of thinking. I certainly understand the thrill of risk but not in this context.
@byroncheung I'm going to make an observation that many here may find offensive but please keep in mind that it's in the spirit of curiosity rather than judgment.
It absolutely blows me away that an affluent owner of an expensive car (Yes; All Porsche owners are affluent. Relatively speaking.) views preventative maintenance as a waste of money. If you know there's a failure rate of any kind why would you not spend $1200 on a speed sensor while you're there to prevent a possible future breakdown and additional labor down the road? As a shop owner, racer, boater and someone who finds tremendous value in my time, I'm truly confused as to what drives this type of thinking. I certainly understand the thrill of risk but not in this context.
Fair question @notfastenough, let me explain how I think about these. What is the failure rate of the speed sensor in the car's lifetime? Obviously, no one knows the actual failure rate, but just to illustrate how different failure rates would affect my decision here:
The scenario I'm facing is I'm going to a shop to do the distance sensor which cost me 8k for parts and labor, I can throw in an extra 1k to do the speed sensor as preventive maintenance, or deal with it down the line if it does fail.
If I get unlucky, it's going to cost me another 7k parts and labor to replace the speed sensor (let's just say parts and labor costs stay the same by the time the speed sensor goes bust).
So we are comparing 7k*probability_of_speed_sensor_failure with 1k outright... the breakeven point of probability_of_speed_sensor_failure is ~14% - aka if the speed sensor failure rate is < 14%, in the statistical sense its' worth the gamble. And this is also with a generous assumption that the new sensor will last for the rest of the car's lifetime - is the new sensor superior to the OEM in terms of material or design? I don't even know... And if the speed sensor failure rate is anything close to 14% we probably would have been seeing PDK owners replacing transmissions at the dealers left and right...
Obviously, not everyone thinks statistically/probabilistically, but that's how I tend to think about these kinds of things. I can understand if someone doesn't want to gamble but rather have peace of mind and be able to sleep better at night.
Last edited by byroncheung; 02-16-2023 at 10:28 AM.
@byroncheung I'm going to make an observation that many here may find offensive but please keep in mind that it's in the spirit of curiosity rather than judgment.
It absolutely blows me away that an affluent owner of an expensive car (Yes; All Porsche owners are affluent. Relatively speaking.) views preventative maintenance as a waste of money. If you know there's a failure rate of any kind why would you not spend $1200 on a speed sensor while you're there to prevent a possible future breakdown and additional labor down the road? As a shop owner, racer, boater and someone who finds tremendous value in my time, I'm truly confused as to what drives this type of thinking. I certainly understand the thrill of risk but not in this context.
Fair question @notfastenough, let me explain how I think about these. What is the failure rate of the speed sensor in the car's lifetime? Obviously, no one knows the actual failure rate, but just to illustrate how different failure rates would affect my decision here:
The scenario I'm facing is I'm going to a shop to do the distance sensor which cost me 8k for parts and labor, I can throw in an extra 1k to do the speed sensor as preventive maintenance, or deal with it down the line if it does fail.
If I get unlucky, it's going to cost me another 7k parts and labor to replace the speed sensor (let's just say parts and labor costs stay the same by the time the speed sensor goes bust).
So we are comparing 7k*probability_of_speed_sensor_failure with 1k outright... the breakeven point of probability_of_speed_sensor_failure is ~14% - aka if the speed sensor failure rate is < 14%, in the statistical sense its' worth the gamble. And this is also with a generous assumption that the new sensor will last for the rest of the car's lifetime - is the new sensor superior to the OEM in terms of material or design? I don't even know... And if the speed sensor failure rate is anything close to 14% we probably would have been seeing PDK owners replacing transmissions at the dealers left and right...
Obviously, not everyone thinks statistically/probabilistically, but that's how I tend to think about these kinds of things. I can understand if someone doesn't want to gamble but rather have peace of mind and be able to sleep better at night.
@byroncheung Thank you! That's a rational explanation however it's based on some unknowns as you allude to. We have no real-world clue, based on the current data what the actual failure rate is for speed sensors and I would submit to you that the replacement of PDK's may be greater than you think. Polling RL members is not even close to a proper survey. 98% of our customer base has never even heard of Rennlist.
I can tell you from experience that 100% of our M96 owners who viewed risk the way you do wish they had spent the dough on a preventative level rather dealing with an engine rebuild because of an IMS failure. It really sucks being on the losing end of risk like this however I can't be too opposed to it because in the long run it's better for my business!
If you know there's a failure rate of any kind why would you not spend $1200 on a speed sensor while you're there to prevent a possible future breakdown and additional labor down the road?
Isn't that basically Pascal's Wager? Good if you have deep enough pockets to cover ALL the bases, but for the rest of us...
Isn't that basically Pascal's Wager? Good if you have deep enough pockets to cover ALL the bases, but for the rest of us...
I know PDK’s can be hellish but hardly fair to compare one’s soul to a transmission decision! 🙄
It’s fascinating to watch how people spend their money. We all have our areas of frivolous spending where budgets are thrown to the wind. It’s a choice and for better or worse routine maintenance isn’t sexy enough for some to justify spending dough on.
This morning we are installing a T-Design9 speed sensor and distance sensor for a 911 PDK, along with training up additional staff on the repair procedure.
__________________ Todd Lamb
Atlanta Speedwerks www.ATLspeedwerks.com
Porsche repairs, servicing, and upgrades / Certified IMS installer / PDK repair experts
Over 150 PDK's repaired and counting: https://youtu.be/m54P_zisEcI
This morning we are installing a T-Design9 speed sensor and distance sensor for a 911 PDK, along with training up additional staff on the repair procedure.
Just curious, about how many on average PDK's do you repair a month?
7-10 a month, approx 60% are just a distance sensor replacement, approx 30% are full PDK rebuilds, and 10% are full PDK rebuilds with HD clutches and internals for higher HP and track abuse.
7-10 a month, approx 60% are just a distance sensor replacement, approx 30% are full PDK rebuilds, and 10% are full PDK rebuilds with HD clutches and internals for higher HP and track abuse.
Interesting, not a ton but definitely a steady stream then. Seems there will be more and more as the miles go up.
What goes into rebuilding a PDK beyond the sensors etc?
Fair question @notfastenough, let me explain how I think about these. What is the failure rate of the speed sensor in the car's lifetime? Obviously, no one knows the actual failure rate, but just to illustrate how different failure rates would affect my decision here:
The scenario I'm facing is I'm going to a shop to do the distance sensor which cost me 8k for parts and labor, I can throw in an extra 1k to do the speed sensor as preventive maintenance, or deal with it down the line if it does fail.
If I get unlucky, it's going to cost me another 7k parts and labor to replace the speed sensor (let's just say parts and labor costs stay the same by the time the speed sensor goes bust).
So we are comparing 7k*probability_of_speed_sensor_failure with 1k outright... the breakeven point of probability_of_speed_sensor_failure is ~14% - aka if the speed sensor failure rate is < 14%, in the statistical sense its' worth the gamble. And this is also with a generous assumption that the new sensor will last for the rest of the car's lifetime - is the new sensor superior to the OEM in terms of material or design? I don't even know... And if the speed sensor failure rate is anything close to 14% we probably would have been seeing PDK owners replacing transmissions at the dealers left and right...
Obviously, not everyone thinks statistically/probabilistically, but that's how I tend to think about these kinds of things. I can understand if someone doesn't want to gamble but rather have peace of mind and be able to sleep better at night.
We've learned a lot regarding probability and perception in the last 20 years with the M96 IMS situation.
As PDK failures and repairs become more common and widely known by mainstream Porsche owners, more emphasis will be placed on how a repair was actually done, including what precautionary measures were taken. I predict down the road that some prospective buyers will assess the quality and potential reliability of a repaired PDK by exactly which parts were replaced, including distance sensor, speed sensor, and friction plates. I think your bet not to replace the speed sensor is going to cost you, one way or another.
We've learned a lot regarding probability and perception in the last 20 years with the M96 IMS situation.
As PDK failures and repairs become more common and widely known by mainstream Porsche owners, more emphasis will be placed on how a repair was actually done, including what precautionary measures were taken. I predict down the road that some prospective buyers will assess the quality and potential reliability of a repaired PDK by exactly which parts were replaced, including distance sensor, speed sensor, and friction plates. I think your bet not to replace the speed sensor is going to cost you, one way or another.
Removing and tearing down a PDK without replacing all potential points of failure while you are already there is like replacing a clutch disk at 80k miles without replacing the pressure plate and throw out bearing. Or, replacing spark plugs at 40-60k miles and reusing the original coil packs. Does not make sense to me……but others differ on this I guess.
We've learned a lot regarding probability and perception in the last 20 years with the M96 IMS situation.
As PDK failures and repairs become more common and widely known by mainstream Porsche owners, more emphasis will be placed on how a repair was actually done, including what precautionary measures were taken. I predict down the road that some prospective buyers will assess the quality and potential reliability of a repaired PDK by exactly which parts were replaced, including distance sensor, speed sensor, and friction plates. I think your bet not to replace the speed sensor is going to cost you, one way or another.
Having just sold a 997.2 with a distance sensor replacement on file, I had the pleasure of reporting full disclosure to the new owner what work was done and by whom the work was performed. The new owner did his due diligence and independently commented on the good reputation of the repair facility (Beck’s European). This resulted in a NON-ISSUE for the buyer (as it should have).
So, to add to the list of reasons WHY someone would shop this out versus DIY, my decision to engage a reputable facility has once again been validated.
7-10 a month, approx 60% are just a distance sensor replacement, approx 30% are full PDK rebuilds, and 10% are full PDK rebuilds with HD clutches and internals for higher HP and track abuse.
02-15-2023, 01:00 PM
