PDK Gearbox Issues

[RandallF]

The following has been received from a member who is having gearbox issues on his 4S. Has anyone else had a similar issue, have any suggestions or can recommend someone to speak to?

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I purchased my 4S 6 months ago with 100k plus mileage - swapped in against 2012 V6 Diesel, wanted V8 - have had much remedial work carried out by specialist garage locally (all marques, low to high value, incl. Aston, Jaguar, Lotus, Bentley, Porsche etc...).

Most recently they suggested car would need replacement rear disc brakes/pads, plus new rocker cover gaskets at some point in the future - I said to go-ahead now rather than wait. Work carried out after parts delay (10 days) - work completed seven days ago. Service guy phoned to say job finished and test drive went well. As I was about to leave to collect the car, was phoned to say not to come as unable to move car from parking area as would not engage forward gears.

Since then they have attempted diagnostics without clear resolution. Just spoken with garage who advise diagnostics suggest unclear issue with gearbox and that hand- brake has gone into "service mode". They are stuck not knowing how to proceed next. In the meantime I have no car!

All useful advice welcome, with my guy saying he would be happy to talk problem over with anyone able to help.

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Grateful for any advice.

Randall

 

[justin f]

i hope this will help rear discs on panamera have to be put into service mode with the obd tool to replace parts of braking system them rear handbrake has to be recalibrated
when calibration is done car will be able to move

from justin

 

[wavydavy]

thanks Justin - so grind in and recalibrate? D.

 

[justin f]

https://www.iscantech.com/2020/08/21/porsche-electronic-parking-brake-epb-adjustment-calibration/You might need to read this fist
From justin

 

[wavydavy]

thanks so much - I'll check it out and keep you posted! David

 

[wavydavy]

Justin - latest update: rear brake work completed and handbrake calibrated etc. Service guy confirmed car had performed well on test and I was asked to collect. Test would likely have been no more than 10 miles, I would think (but I will be asking...) Car came home (less than 10 miles) with no problem. Several days later I took it to car wash (5 to 6 miles away), it broke down on return journey within 1/2 mile of home - same problem, no gears in auto, recovery mechanic got the car home in manual, with no issue. Following morning car went into all auto gears and was put on flatbed truck to return it to service garage where it now sits...again....suggested by guy collecting that PDK good when cold but when fluids reach working temperature, problem arises. Could next step be to replace PDK temperature sensor, I wonder.....service guys will re-run diagnostics this week....I am not happy to accept back until they have taken for 15 to 20 mile test to prove all good...

 

[wavydavy]

fault codes showed previously - P0700 and P17B2.....

 

[Motorhead]

Transmission control unit and clutch faults? It sounds as though there could be a few issues there, so best for your garage to run some appropriate Porsche-specific diagnostics [PIWIS or equivalent] with the transmission cold and up to working temperature to see if that provides answers to your problem.

At 100k+ miles it would be useful to check when the PDK fluids [clutch and transmission] were last changed, and renewing both - and any filters? - could help, although not guaranteed.

Here’s some potentially useful background reading on some PDK transmission problems:

Porsche PDK Transmission Problems - Common Issues Explained

Porsche PDK transmission problems and common issues explained, with fault codes, possible resolutions, and suggested next steps.

www.pcarwise.com

Jeff

 

[wavydavy]

thanks Jeff - will spk with garage guys in the week - mileage reading 93k, my mistake...pretty sure PDK fluids not changed, possibly never changed...

 

[wavydavy]

Jeff - can finally report that after diagnose by Porsche registered Specialist that no codes now showing, "likely 2nd clutch is slipping". Now looking to have rebuild somehow - either that or I scrap the car, given am unwilling to go down the new gearbox route - would you recommend a refurbished gearbox if i can locate one? Or consider one from an otherwise scrapped Panamera, ie insurance write-off for bodywork damage???? Your opinion would be very welcome at this point. David

 

[Motorhead]

Very sorry to hear that David. I’m no expert on the PDK transmissions but my understanding is that Porsche don’t consider them to be repairable and so don’t make spare parts available and will only supply replacement units, which I don’t think are on an exchange basis. They’re manufactured by ZF so presumably parts are available, but I’ve no idea how anyone rebuilding or replacing your clutch-pack would obtain the necessary parts to do so. Added to that I’m not aware of anyone offering a clutch-pack replacement other than a New Zealand racing outfit who will supply and fit an upgraded pack for race use, so that’s a nonstarter for you. Maybe you can find a UK-based auto-transmission specialist who will take on the task, but unfortunately I very much doubt it.

As you suggest, I suppose it would be worth trying to locate a used unit - if you can find one! - but it would have to be compatible with your series of Panamera and would require specialist electrical knowledge and skills to integrate it properly so that the engine and transmission electronic modules communicate with each other. There are a few specialist Porsche breakers such as 9 Apart Ltd who may be able to help and who will be able to give you a scrap value for your car.

Not great news I’m afraid, but I do hope that you find a satisfactory solution to your dilemma.

Jeff

 

[wavydavy]

have also seen on Us forumss that solenoid pack can cause similar overheating, resulting in slipping. Otherwise, possible worn clutch?

 

[Motorhead]

At 93k+ miles there will be clutch wear David, very much dependent upon usage of course, and I would imagine that there’s an automatic adjustment mechanism to compensate for this within limits. Quite naturally, a slipping clutch will generate a significant amount of heat!

Other than replacing the clutch-pack oil I think the only other remedy available to your garage is to carry out a software reset? The only other remedial work I’ve seen reported relates to the main body of the transmission itself: various sensors and valve-body solenoids. This US company is an example:

Porsche PDK Transmission - Now REPAIRABLE - brrperformance.com

Porsche PDK Transmission – Now REPAIRABLE This post / blog article talks about the ability to repair a Porsche PDK transmission for certain models / generations. We have had many […]

www.brrperformance.com

Jeff

 

[wavydavy]

thanks Jeff - I will be visiting repair shop early next week to discuss further - will update them on your latest suggestions, if that's ok...otherwise, thanks for your help to date and wishing you a good weekend...D.

 

[Motorhead]

David,

Just to mention that a very cursory look online indicates that PDK clutch slippage isn’t unknown, although I would imagine that it’s fairly rare. I’ve no idea how these occurrences relate to your problem, but no-one reports having any error messages, so just swapping components in an attempt to solve the problem will always be hit-and-miss … and potentially very expensive! Here’s an example of a relevant post:

Panamera PDK clutch blipping issue - 6SpeedOnline - Porsche Forum and Luxury Car Resource

Panamera - Panamera PDK clutch blipping issue - Dear Porsche friends, As a newby and long time Porsche enthousiast, I am reaching out to this community to hopefully find out if there is any knowledge and possible solutions to an annoying PDK issue I have. I live in Switzerland and after 5 x 911...

www.6speedonline.com

Interestingly, on one 911 discussion it seems that the recommendation is to use only the official Porsche clutch oil rather than an equivalent spec available from other suppliers [one chap says he cured his clutch slip by replacing his Motul oil], so you may wish to bear this in mind if you’re planning to change the clutch oil. Having said that, another chap mentioned that a BMW mechanic [BMW also use ZF dual-clutch transmissions] told him that it was better not to change the oil on high-mileage cars, so your guess is as good as mine as to whether or not it’s desirable, and ditto for carrying out a PDK reset.

Jeff

 

[wavydavy]

thanks Jeff - the car is with Porsche specialist at the moment - he is checking availability of ZF parts in the EU, he thinks can be found in the Netherlands. I will keep him upto speed with your advices....D.

 

[BrianJ]

Fascinating article. Especially right at the end where he gives the Panamera example which turned out that just update/reload/recalibrate the software fixed the issue and the hidden PIWIS opportunity to increase the clutch pressure.

 

[wavydavy]

fingers crossed it proves so simple, Brian....

 

[wavydavy]

Below a copy post on US forum -

"2013 Boxster S ~70k miles; original PDK fluid (120kmi/12y service interval).

• Clutch engages normally when cold; drives normally; no codes.
• After ~10min of driving, clutch 1 (gears 1, 3, 5, 7, R) begins to have trouble engaging - after releasing the brake pedal, clutch 1 will only partially engage until more throttle is added to get clutch 1 to fully engage.
• Clutch 1 engagement progressively deteriorates; more and more throttle is needed.
• After ~20 minutes, clutch 1 will completely fail to engage; code P17B1 was obtained through a scanner.
• Once the car cools down, the code is gone and the PDK is fine until warmed up again as described above.
• The clutch chamber was low on FFL-3 fluid by about 1 liter so it was topped off, but the behavior continues.

Could this be a solenoid (EDS1) problem? If so, why would the issue only occur when the PDK is warm? What steps would you take to begin troubleshooting? Any help would be greatly appreciated."

what is interesting is that 10 minute followed by 20 minute issue is an exact carbon-copy of my experience...though my code showed P17B2 on RAC scanner....following morning car drove normally onto RAC flat-bed, engine of course cold....

 

[wavydavy]

my experience as follows - car was throwing all manner of codes, I had repairshop replace all fluids (not PDK?) and spark plugs - I asked for ignition coil packs but they failed to do this - after pick-up car continued to throw codes - I returned to repairshop, asking again for ignition packs - they did so, hey presto all codes cleared never to return.Car driving rock-solid - went on 550 mile roundtrip, no issues whatsoever. On return car taken back into repairshop who had recommended rear discs and pads should be replaced, plus rocker cover gaskets replaced as slight weep - this all done. Was phoned to collect, road test showed all good (likely no more than 10 minutes given shop location). As about to leave to collect, they phoned to say not to come as car now not going into gear (was of course now warming up). They had local guy with Porsche knowledge to come over - he "recalibrated back brakes", they took on test again, again saying now no issue going into gear (again car was cold). I brought car home (about 15 mins drive). Following day took to carwash (10 mins plus distant), on slow-speed return journey through town car behaved jerkily, finally giving up the ghost on hill close to where we live (now 20 mins approx) no gears. RAC guy got car home using manual, checked on OEBD and found P17B2...following day car drove happily onto flat-bed.....my experience identical regarding timing...