Cayman 718 GPF Failure

[911hillclimber]

Repeating the condition, the analysis, and the findings is important.
Might I suggest a 'sticky' link to a purpose written by Dave summary of this ridiculous issue at the end of further posts so anyone new to this can gat to a tech precis instantly, and no need to scroll all the pages?
If this is printable an owner can take this into an OPC or most likely now a Porsche Independent to persuade or guide the workshop?

My perception of Porsche continues to sink.

 

[Cyclemotor1958]

Hi Tony,

Thanks for spotting the ash value 76.08% across both of these vehicles GPF data, if we could get more GPF data reports showing multiple visits to our Dealers I'm sure we could find more reoccurring information.

Its often said its all in the detail, so Ive compared your data to the other cars data with both showing the same ash value above.

Your car The other car

K211 soot 0.00 0.00
K221 soot 1.96 5.88
K230 ash cal 0.00 0.00
K231 ash measured 76.08 76.08
K241 diagnosis val 0.00 0.00
T255 exhaust temp 512.48 373.79
T251 exhaust temp 488.85 360.04
K251 diff pressure 6.22 0.00

So if you look back at our other cars differential pressure readings from the PDI you can see reoccurring hPa readings.

Differential Pressure hPa

PDI 2.90 Ash load 0.00%
Wheel repair -0.58 74.12%
1st service -0.58 75.69%
Regeneration 0.00 75.69%
Mot 0.00 76.08%
Diagnostic 0.17 100.00%

This car also had a soot measured K221 value of 21.57% when the car had covered only 14 miles, before he took delivery of his new car.

And also it had the DTC code P0234 present on quite a few visits.

This code is a turbocharger overboost code, this is well known on these cars, usually down to a seizing actuator linkage pin.

There has been a bulletin out on this issue for quite a while.

When you look at the internal memo that was sent out last March it mentions several causes of high ash loads that have been found across various vehicles.

It said it was important to check the operation of the turbocharger actuator to ensure it was functioning correctly.

So when this car went in for the diagnosis of the warning light on, and the fault code P242F ( ash load to high) why wasn't this detail looked at more closely.

Why wasn't the checks on the memo carried out before the customer was contacted.

He was told the GPF had to be replaced, at a cost of £9,300.00 and any other diagnosis time would be charged to him.

He has asked several times for a back pressure diagnostic check to carried out, and he would pay for it, but this has been refused every time.

They have the PWIS data that shows this fault was on the car at the first service, and they even carried out a regeneration to try and reset the ash %, it didn't work as you can see.

And the worse thing is, the customer wasn't told about the regeneration attempt, the high ash value, and was never aware of the turbocharger issue either.

We are over 5 months in with this car, trying to get the Dealer to do the correct diagnosis of this fault, even though they have an internal memo that confirms that this is a manufacturing defect, and has been for a very long time.

Remember the memo says the new GPF (982254400AF) has been modified to prevent this issue. All vehicles with a production date later than December 2019 should already have the modified GPF fitted.

So they would know which cars didn't have the modified filter fitted durring the first year of production up to December 2019.

Their warranty data would show the modified replacements, so all these other cars should have had the new modified filter fitted.

We have been slowly dealing with these other cars, its taken us over three years, but sadly we couldn't deal with them all.

Whats even more appalling is that most of the owners who contacted us that required new filters have sold their cars, because they were blamed for this fault, wrong engine oil and driving style.

This is absolutely bloody ridiculous that these Dealer's and Porsche are not telling the truth about this well known fault on this car, its scandalous, and it has to stop.

Dave

 

[Wrightrubber]

Hi Dave
It is totally baffling to me, that Porsche and the Dealers don't understand what they are doing, they continually want to charge the customer £9500 for a filter that isn't blocked and replacing it doesn't solve the problem, look at all the work they did to Paul's car and it still didn't solve the issue, proving to me that they really don't understand what they are doing!!!
Keep up the good work.
Regards
Mark

 

[Cyclemotor1958]

Thanks Mark, and 911Hillclimber,

Really appreciate your comments, we will soon be hopefully getting a video showing a separate backpressure reading of a car with a 100% ash reading, so we can prove how ridiculous this situation really is.

Sadly it will not be coming from a Dealer

Will keep intouch
Dave

 

[911hillclimber]

Wonder how the next owners of these cars with the fault get on?

The car gets sold on somewhere to someone who gets the light.

MoT failure notice will bring the car to a quick off the road and then the car is a paper weight unless a fix is found.

The number of irritated people will grow! And possibly never buy another modern Porsche unless brand new.
Slippey slope to me...for Porsche.

 

[Wrightrubber]

Exactly right! I have owned four Caymans, all direct from Porsche but I will never own another one after the way I was treated by Porsche GB and the Dealership.
Regards
Mark

 

[Motorhead]

I’ve said it before, but this issue really is a shocking indictment of Porsche, a company which has always prided itself on its engineering prowess. The fact that it’s clear that the factory is either unable - or unwilling? - to instruct its dealers to carry out some basic, simple tasks identified by Dave beggars belief!

Keep up the good work Dave. Hopefully your continued perseverance eventually will lead to the correct and positive outcome for those owners affected.

Jeff

 

[Wrightrubber]

Hi Dave
Just to re-cap how I was treated by Porsche OPC, when I was told my filter was 100% blocked and needed replacing, at a cost of £5800 + VAT, (it was 3 years ago....a lot more expensive now!) they said I had to pay for it as it was my fault, due to my style of driving, short journeys!! I pointed out a few things, 1) I was never informed it had a GPF fitted.... 2) I was not informed I couldn't drive it for short journeys.... and 3) I had extended warranty and nowhere in the warranty did it mention GPF in the exclusions (the wording was changed later on to include the GPF in the list of exclusions - I believe this was another indication they knew this was going to be a problem!!!)
You (Dave) intervened and they agreed Porsche GB would pay a third, the Dealership would pay a third and I was to pay a third, I reluctantly agreed, after them having the car for 9 weeks, I was also told by the dealer if I didn't accept this offer I had to collect the car and take it elsewhere!! Excellent customer service...I don't think!! They then sent me the GPF report and you (Dave) looked at the data and it didn't make any sense, the filter couldn't possibly be blocked, armed with this information I went back to the OPC where I purchased the car (part of the same group as my local OPC) and they agreed to refund my contribution.
They agreed to monitor the ash content and I returned to the dealership on three further occasions and the percentage readings were back up to 50%+, when I asked what happens when it gets to 100% I was told 'it will need replacing again but you will have to pay the full amount'!!.
I was also told by the service manager not to drive the car if the journey was under 30 mins!! Absolutely ridiculous!! So basically I had a car that I could only drive on specific journeys. I've never heard so much rubbish in my life!
The thought of going through another battle with them when the filter is a 100% full (which it never was in the first place and replacing the filter doesn't solve the problem) was too much so I sold the car and genuinely will never buy another.

Regards
Mark

 

[Cyclemotor1958]

Hi Mark,

Wow that was over three years ago now, and my first post on this subject was to mention the possibility that a faulty AOS on your car could cause your GPF filter to block up with Ash quicker than it should do.

We've discovered alot along the way, it wasn't a faulty AOS, because if you remember I sent you a manometer to check it yourself. We also discovered the correct vacuum reading for a full functional AOS on your Cayman 2.0.

We also discovered that Porsche Customer Care confirmed in writing to one of our owners that had a blocked GPF filter replaced by Porsche Reading. Was replaced because the Technical and Warranty departments considered it to be a manufacturing defect.

We also discovered this same issue on a 991 2019 car, which had the same GPF data that made no sense at all.
We worked very hard on this problem and convinced the Dealer and Porsche to pay for the new filter.

This new filter was checked a while ago and its already got 21.90% of ash recorded.

We discovered after checking lots of our faulty vehicles that none of these cars had an adaptation facility on PWIS to reset either the differential pressure sensor and the GPF to zero.

We discovered an internal memo that Porsche sent to all their Dealers last March that informed them to check for other possible causes of internal oil consumption if the car was showing the fault code P242F.

We also discovered a written conformation in the memo that Porsche had been having the very same issue on these cars in the first year of production.

They came up with a modified filter with a new part number.

We also discovered that it wasn't just model year 2019, we found cases on 2021 and surprisingly a 2023 vehicle with the same GPF data showing an ash value of 50.59%, after only 16K, with no differential pressure showing.
On this car the owner asked the technician who gave him the Ash value, did his car have the adaptation function, he laughed had said none of these cars have it.

We have finally discovered this fault has nothing to do with wrong engine oil, driving style, incomplete service history, its just plain and simple software.

We have further confirmation its software, but we will leave this for a other post.

Sorry Mark this has gone on a bit, but we have invested over 3 years in providing these discoveries.

Kind Regards
Dave

 

[Cyclemotor1958]

Morning Guys & Girls

We are still getting reports of Porsche Dealers refusing to carry out a simple back pressure check on the cars they say need the new modified GPF filter.

This has been going on for over three years now, their reason for not doing this simple test, is its not part of the Porsche diagnostic procedure and Porsche will not allow them to do it.

When our 718 2.0 and 2.5 owners are told that they need over 9.5K to replace their filters, they would assume that the diagnosis carried out regarding this fault would be accurate bearing in mind the considerable cost.

So why are Porsche Technical not authorising this back pressure check to be carried out, afterall its a very simple thing to do, doesn't take much time, and while its being done, it confirms that the reading from the differential pressure sensor taken on their PWIS tester is accurate.

We have seen over the last 3 years looking at the GPF data that these differential pressure sensor readings often seem inaccurate, and we have seen readings duplicated over many PWIS data reports given to us.

And one thing thats always been very odd, is that on all the faulty cars we have been involved in, not one has had a reading high enough that would confirm a blocked GPF filter, either with soot or Ash.

This has ways been my main reason for speaking to Porsche Technical to ask them to look at one of our faulty cars. They could carry out the back pressure check and see for themselves.

I have contacted Porsche Stuttgart twice now asking for help and both times they have told Porsche GB to contact me, they even gave me a case number 8000654198.

Its been 10 weeks since I had contact from Porsche GB, giving me the case number. I have made several attempts to speak to the Technical Department but they continue not to respond even though I have a case number.

So enclosed with this post is a video that shows a manometer (pressure gauge) been fitted to the differential pressure sensor pipe from a DPF filter to the sensor.

It shows how easy it is to check the actual DPF pressure using a seperate tool.

The reading this quy gets is 13 millibar which is the same reading as in our measurement in hPa, he even increases the revs to show the pressure increasing, another test that confirms a possible back pressure restriction.


This information is half way through the video, but its worth the wait.

I know Iam repeating myself again on this very suspect of diagnosis, but this is very important.

I have a copy of the patent Document that Porsche submitted dated 26th December 2019 that covers the method for determining the loading state of a particulate filter of a motor vehicle.

Its 8 pages long, with lots of detail.

Enclosed is the first page, under the ABSTRACT section, right hand side of the page it explains the role of the differential pressure sensor.

The other pages of this document have more detail including the algorithm thats used to calculate the loading of the filter.

To sum up.

If there is any issues with the differential pressure sensor readings this algorithm can not function correctly.

The fact that we can not adapt the algorithm, (re-set to zero) when the the new modified filters are fitted is ridiculous.

Because on the original filter if it was proven that the filter wasn't blocked, by checking for any pressure present, then a simple adaptation could have been carried out.

No need to fit another GPF filter

Generally the adaptation is telling the algorithm that a new GPF or DPF has been fitted. Its done all the time on our Diesel Particulate Filters.

The algorithm sees this information and resets its calculation to zero regarding the ash and soot loading of these filters.

And the fact that we cannot adapt a new differential pressure sensor after its been fitted, makes this situation even worse.

So its crucial that the correct diagnosis is carried out on these vehicles, and at the moment it's not being done.

This has been proven beyond any doubt because on 13 of our cars that have had new modified GPF filters fitted, they all had ash loadings coming back at unacceptable levels.

So why now are Porsche GB still allowing their Dealers to miss diagnose this fault again, and again.

Why did they authorise the replacement of these filters on some of our cars, but have decided now that no more help will be given.

We will carry on with our quest to try and convince Porsche and their Dealers to do the right thing, stop fitting expensive GPF filters that do not fix this issue. And bring out a software improvement that will enable the adaptations to be carried out on both the sensor and the GPF.

Enclose below, the front page of the Patent Application, and the video, and the response from Porsche GB regarding my dealings with Stuttgart.



Dave

 

[Scrounger]

Dave

Given Porsche GB have not contacted you in 10 weeks apart from it being outrageous, you need to step it up to the next level and make Porsche GB sit up at take note.

Dan

 

[Cyclemotor1958]

Hi Guys & Girls

Sorry to bother you again, a friend from over the pond sent me this info, hes been following our Porsche Club Forum for some time.

Whats interesting in the information he sent below, is this sentence.


The accumulation of ash in the GPF affects the exhaust back pressure and reduces the amount of soot that can be stored before requiring a regeneration.

This is what we have said from day one, and backs up our claim that this backpressure check is being over looked.

If these filters are blocked with ash, where does the soot go, remember recently one of our cars that covered over 15K miles between the diagnosis of a faulty filter, to it actually being replaced.

And this only happened because the new owner shortly after purchase had the warning light on, and his suppling Dealer replaced it F.O.C.

This is why its important to be aware of how you GPF is performing, regarding the differential pressure sensor values and the ASH % in these filters.

All this information is downloaded off your car when you go in for service or repairs, its under the GPF section, all you have to do is ask for it.

Dave

 

[911hillclimber]

Can't help feeling Porsche (at whatever level) just will do nothing to those with these cars/light problem.

Not in their interests to invest time in it and these customers should have bought a new Porsche in 2022 when the warrantee ran out.
All a bit like Bore Score and IMS etc, same old story, historic customers do not matter, but I think many buy BMW and fat AUDI RS's instead.

The best result will be an 'aftermarket' fix to the program to allow a reset of the light that can be used again (and again if required) to remove the light as long as the back pressure is 'Zero' across the filter.
What happens in 10 years time is beyond me, but many could have been scrapped by then as electric is fully the Only Option.

 

[Cyclemotor1958]

Hi 911hillclimber, and Dan,

In 2019 Porsche carried out a Dealer software update on Panamera for emissions, I remember this well, has I was still working at an independent Porsche specialist.

I believe it involved updating and reprogramming the DME control unit.

Obviously this would have been very expensive to do as the Panamera and our 718 cars do not feature over - the -air (OTA) software update capability, that could cover adjustments to emission control, they are to old.

So full system vehicle firmware updates have to be done at the Dealership.

This is because critical emission or engine management updates must comply with very strict European and type approval regulations which can only be done correctly in a Dealership environment following strict protocol required.

So it begs the question why can't our cars have a recall carried out, similar problem, the issue on the Panamera was found to be not correct, and they attended to it. Our GPF issue was found in the first year of production according to their memo.

Just another question we would like Porsche to answer.

Again the memo says it all.

Its their diagnosis afterall, not ours.

This issue on these cars is a manufacturing defect, we have written confirmation from their own Warranty and Technical departments on record to prove this statement.

We have further proof that issue was around well before these vehicles went out of manufacturers warranty.

Hi Dan,

We are certainly not resting on our laurel's, we are chasing Dealers for authorisation of these filters only because they believe this modification works.

They won't listen to what we are saying , but once these filters are fitted they will eventually have the problem of what to do next when the ash software measured % comes back.

On our cars that had new filters fitted after showing the 100% ash warning light on, it took an average of around 5 to 6 years to get to the 100% level.

We have monitored these cars and the ash % is coming back in less than a year of driving and at very low mileages covered.

The worst example of this was Paul's car it never got out of the Dealership who sold him the car, he never drove it again.

This is definitely a case we would like to discuss with Porsche Technical, who authorised all this time, and parts cost, but never authorised a simple back pressure test.

And including the original GPF, it had 2 others fitted trying to sort out this ash issue and they both were modified parts.

So whats the point of fitting parts that don't fix the problem.

Paul's case cleary demonstrates the incompetence of their diagnosis, just imagine if a customer had to pay that bill.

So we will be stepping up to another level if Porsche and their Dealers continue to ignore our requests for the correct diagnosis of this fault.

The more they ignore our 718 owners the more persistent we will be.

This is not right, we expect better from Porsche, and certainly we expect better from the Dealers, these cars are brilliant, there is nothing out there that can equal the driving experience these cars give our owners.

Our job on these forums is to try and convince Porsche to do the right thing, thats all.

Dave

 

[squicker]

Has anyone taken Porsche to small claims on this, while within the 6yr limit? With the data you have, an independent engineers report, and Porsche making statements like ‘you can’t do short journeys‘, it would be a shoe in. Whilst SC does not set precedent, one win could be waved under Porsches nose in other cases.

 

[patersont718t]

Hi all, excellent information—thanks for sharing.
Dave, would it be possible for you to send me the PDF version of bulletin #2506? As you know, my car is booked in this Tuesday for further investigative work relating to the GPF, which Porsche has approved. I assume this will follow the Porsche memo you previously provided.
My car’s ash/oil levels have fluctuated up and down over time. I received the 100% reading along with the EML in May, and then in June it dropped to 76.08%, at which point the EML went off. However, the fault is still recorded in the diagnostic report.
The fault has been described in the diagnostics as below so even the diagnostic reports are clearly showing software issues when the fault is being communicated:

1. 18th May -100% ash/oil fill level - Active Fault & EML
2. 26th May - 76.08 ash/oil level - implausible signal & NO EML
3. 14th June - 76.08 ash/oil level - implausible signal & NO EML
4. 26th June - 76.08 ash/oil level - inactive & NO EML

Having the bulletin to hand over will only strengthen my position that the fault is not a blocked GPF requiring £9500 of my money.



Keep up the good work

KInd Regards
Tony

 

[patersont718t]

Has anyone taken Porsche to small claims on this, while within the 6yr limit? With the data you have, an independent engineers report, and Porsche making statements like ‘you can’t do short journeys‘, it would be a shoe in. Whilst SC does not set precedent, one win could be waved under Porsches nose in other cases.

Definitely part of my plans if they persist with me footing the cost of the repairs.

 

[Scrounger]

Don’t forget to take it to the motoring press as well. You may find Porsche will react much quicker to your issue.

Dan.

 

[Cyclemotor1958]

Hi Tony,

Ive just spotted something that could be a clue to whats going on, or something else.

Remember our Dealers and Porsche have always looked for evidence that the wrong engine oil was used in your cars. Along with your driving style, to many short journeys, utter nonsense Iam sure you will all agree.

The release date on the bulletin I previously posted was the 7th March 2025, The internal memo on our cars had a release date of the 3rd March 2025, 4 days between them.

Hi squicker,

Thanks for your comments, we have always intended to possibly get the courts involved against the Dealers for the miss diagnosis of this fault.

But we held back thinking common sense and our belief that surely these Dealers at some point would be more sympathetic to our owners position, afterall its their customers, and future customers that are suffering.

You only have to look on Dealers sales forecourts to see, there's not many of these cars for sale, bearing in mind these cars are in the entry level category. Which is a great shame because this fault can be fixed, we just need them to do it

They could put pressure on Porsche for carring on with this charade, because between them the are condemning our Cayman and Boxster 718 2.0 and 2.5 to another manufacturing defect that they at the moment will not be put right 100%.

If every Dealer got together with Porsche I am sure they could move things along for us.

We have 180K views on this issue, the Porsche Club Forum have never seen anything like it, and hopefully will never see any thing like it again.

Enclose a copy of the first page of the bulletin we have just spoken about, along side our internal memo on the 718 cars.

I have had to remove the name of the author of this internal memo document along with the release date, so I don't get into more trouble, but please trust me the date is on the official document.


Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Has you know we have been trying to get a back pressure check done on one of our faulty 718 cars for over 3 years now.

Obviously no Porsche Dealer would help us, and its been the same for independent Porsche garages also.

Nobody would help us with this simple check, for fear of possible repercussions from Porsche and their Dealers.

Well, we have at last a video and photo evidence of the backpressure recorded on one of our faulty cars with the usual K231 oil ash load measured at 100%, and no soot values present as usual.

A manometer was used, but it was set to Kpa, not our usual hPa.

The reading does fluctuate so Ive taken a snapshot reading of 0.47 it did go lower, and converted it to hPa, so its now 4.7 hPa, convert that to psi,
and you get a massive 0.0681677367 psi reading.

Sod all.

So we have a car, we have the PWIS diagnostic proof of the cars GPF data, and we now have the video and a photo showing no back pressure present at all.

This evidence proves 100% that all these checks mentioned on the internal Porsche memo sent out in March last year, didn't need to be done at all.

Don't forget Paul's car

2 x Modified GPF filters
1 x AOS
1 x DME
2x Differential Pressure Sensors
1 x engine removal stripped down looking for any internal oil consumption issues, none found.
1x New exchange engine
1x Turbo

And don't forget our Dealers have wanted to charge our owners for further diagnostic checks on these cars with this fault.

Just a simple back pressure check would have proved that the original GPF was not the cause of this issue.

They didn't need a modified filter, we know that after a lot of testing on 13 of our cars, that had these filters fitted, they still have this ash problem, the same problem they had when they started. Its not at 100% with the light on, but its far to high for the mileage covered.

We could go on and on about the major miss diagnosis of this fault by our Dealers, and Porsche, but what's the point, who will listen to us.

Because between Porsche and their Dealers someone has lots of explaining to do and what are they going to do now.

Enclosed is a copy of the GPF report on our car, showing the 100% ash measured value, and the photo taken of the back pressure recorded at the same time for you all to see.

Regards
Dave