Cayman 718 GPF Failure

[Motorhead]

Please correct me if I’m wrong Dan but I believe you had a positive outcome when you involved Auto Express to assist you with an issue on one of your previous cars [Mini?]. Personally I can’t see any problem for anyone who has encountered this problem - Club member or not - in contacting them as an individual who feels that they aren’t being treated fairly by Porsche. In fact they would be doing owners of affected cars a great service, many of whom won’t be Club members or readers of these pages and aren’t necessarily aware of the issues and the invaluable research and work that Dave has done over the past 2-years to save owners eye-watering GPF replacement costs.

The only cautionary note in following such a course of action is if an owner is engaged fully with their Porsche dealership in finding a solution, where such an approach is liable to alienate the dealership and Porsche GB.

Just my tuppence worth, as usual.

Jeff

 

[Scrounger]

I did Jeff. I had an issue which I raised with the dealership (MINI) and it fell on deaf ears, that was until after being ignored on numerous occasions I emailed Auto Express and within a week MINI were on the phone to book my car in and engineers from BMWs engine department were enroute to examine the vehicle and DME. Strangely enough a week after that a new DME flash solved the issue.

Dan

 

[Voodoo_Blue]

We used to have an excellent superb relationship with Porsche GB at Reading and they would be most helpful with he club in many ways.

There have, of course, been ups and downs as with any commercial relationship and the club had a dreadful relationship in 2011/2012 era. After this we steadily built up the goodwill between us and we really did get on famously, restoring the association we had previously. We valued each other.

I am no longer privvy to the relationship and I hope that it is as healthy as it used to be. Or has something occurred to dampen the relationship? Who knows.

Maybe the board, and in particular the Chairman and Register Director have been to Reading to discuss this quite serious situation and get some resolution for all affected Cayman owners. But unless they come on here or communicate with the membership then were all in the dark.

I believe the relationship is still in a good place Peter but like you I've not been directly involved for a while so don't have an up to date picture. The recent senior management changes in the UK may have also impacted any progress as it can sometimes take a bit of time to build a rapport while people are settling in. Having said that I also have experience of them making decisions on issues that we have helped influence so they can be receptive given the right set of circumstances.

I also know that John has been involved on this with the Board and has been updating people on this thread with the latest information as it's become available but on this issue it seems that so far we've been unable to get the action we would like.

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Received this message last night from another 718 owner thats having an issue with the GPF filter.

Hi , I’ve also just been told after engine dashboard warning
That it’s my gps filters which need replacing after diagnosis test.
Only owned my 2019 cayman for 4 months.
Spent majority of my pension lump sum on it .
Quoted nearly £8,000 to replace.
Unfortunately it’s not under warranty.
Could you advise me please.

WHEN IS THIS GOING TO STOP

We will of course do our best to help.

Porsche should now send out another internal memo instructing the workshop not to replace these filters, to stop this miss diagnosis.

Its incredible that Porsche are still allowing this repair to replace a part that doesn't need replacing.

Surely the Service managers in these Porsche Dealers must know that fitting these filters is pointless, and it doesn't fix the problem.

And they are now trying to convince us that a 54% oil ash reading in a new filter is the normal according to new instructions from Porsche Technical.

I have made contact with a friend of mine at the DVSA to see if they can help us out.

We are now on 97 thousand views at the moment, thanks again for your views and interest.

Regards

Dave

 

[911hillclimber]

If the Club's direction is to work on behalf of the members, in this case a very small part of the membership, the surely 'If at Fisrt you do not succeed, then try Again' could be the approach, esp as more sound reasoning has been documented here.

If the Club's approach is that they have tried within their boundaries with Porsche GB and The Factory, then the matter will be closed.
Question asked, response given, carry on with the Club.

I feel the Club has done what it can, and that the resolution will only be found via alternative pressures, but who at Porsche is really going to bother?

Their mass is far greater than us!

This should not hamper the progress made to understand and prove the facts by the people involved on here, at least they do have the drive to carry on.

 

[Cyclemotor1958]

Hi, 911Hillclimber,

Without prejudice

Yes we do have the drive to carry on, I have personally invested over 2.5 years on this campaign and we will not stop till this problem is fixed.

A year ago this GPF P242F (oil ash load exceeded), was recognised by Porsche Technical and the Warranty Department has a manufacturing defect, and the filter was paid for by Porsche.

We have the email to support this statement.

It took us over 5 months to make them change their mind.

Sadly the oil ash came back at over 55%, and because of this the owner sold the car.

They couldn't carry on, with all the stress and worry, and in the process lost quite alot of money getting rid of a car they loved, and never wanted to sell.

So here we are after all this time, all these GPF filters replaced with a modified part, and all the other parts including engines, turbos, AOS, engine strips, sensors, what next, and we still have the same OIL ASH levels to high for the time and mileage covered.

The only positive to all this time, and work carried out, is we don't have the P242F DTC light on, but for how long.

When you look at the brilliant technical advances Porsche have made building the Taycan, why can't we have a relatively simple software adjustment on our cars, to fix them once and for all.

Sadly, Porsche in their denial of this fault, have made this fault alot bigger than it should have been.

Hopefully people will remember the 718 Cayman and Boxsters 2.0 and 2.5 for being absolute brilliant cars, not a car to be avoided.

Its up to you Porsche, but we are not going to stop, until you sort this problem out.

Regards

Dave, and all the people who have suffered with this fault, and are still suffering.

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Over the last week I have been helping a few more 718 owners with the GPF oil ash problem.

If we get any cars that have been sold outside the Dealer network with this issue, we will be booking them into the nearest Porsche Dealer to get the fault confirmed.

We will ask the Dealers to raise a case to Porsche Customer Care on the grounds of a known concern, that they have been aware of for sometime, and under the heading of an emission control defect.

It goes without saying, on any Dealer sold cars, that this will be done straight away.

After all the parts that have been fitted to these faulty cars, it clearly demonstrates that they agree with us, that these cars emission control oil ash readings, were not correct, and still are a cause of concern.

We now have 99,000 views on this subject, last September we had only 15,000.

Regards
Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

I would just like to show you all the differences between the GPF reports on a 2019 Cayman 718 2.0, a 2019 991.2, and a 2022 Cayman 718 GTS 4.0.

Lets start with the Cayman 718 2.0, this is a typical report, when the filters oil ash load reaches 100% and the warning light comes on with DTC P242F.

K211 Particulate filter bank 1, soot load calculated 0.00 %
K221 Particulate filter bank 1, soot load measured 0.00 %
K230 Particulate filter bank, oil ash load calculated 0.00 %
K231 Particulate filter bank 1, oil ash load measured 100.00 %
K241 Particulate filter bank 1, installation test diagnosis value 0.00 %
K251 Particulate filter bank1, differential pressure current value 2.32 hPa.

Note: No readings in either soot values, the 100% reading is in the measured value, not the calculated, and the differential pressure reading is unbelievably low, considering its supposably blocked, and needs replacing with a modified part.

Lets look at this 991.2 2019, this vehicle required a replacement bank 1 GPF filter, not covered under warranty. We managed to get a copy of the GPF data, and found these readings below.

K211 Particulate filter bank 1, soot load calculated 0.78 %
K212 Particulate filter bank 2, soot load calculated 0.78 %
K221 Particulate filter bank 1, soot load measured 0.00 %
K222 Particulate filter bank 2, soot load measured 0.00 %
K230 Particulate, oil ash load calculated 0.00 %
K231 Particulate filter bank 1, oil ash load measured 100.00 %
K232 Particulate filter bank 2, oil ash load measured 58.04 %
K241 Particulate filter bank 1, installation test diagnosis value 0.00 %
K242 Particulate filter bank 2, installation test diagnosis value 0.00 %
T255 Particulate filter bank 1,exhaust gas temperature in filter calculated 346.66 degrees C
T256 Particulate filter bank 2,exhaust gas temperature in filter calculated 346.35 degrees C
T251 Particulate filter bank 1,exhaust gas temperature upstream of filter calculated 61.04 degrees C
T252 Particulate filter bank 2,exhaust gas temperature upstream of filter calculated 61.04 degrees C
K251 Particulate filter bank 1, differential pressure current value -0.25 hPa.

When you look at the data above, we argued that if the bank 1 Particulate filter was blocked with ASH, how can the exhaust temperatures be the same. Surely if the filter was blocked you would see a difference in temperature, it would be a lot higher due to the backpressure.

Also the figures shown didn't look right, and has with the K230 Particulate, oil ash load calculated figures on the above 718, no readings were recorded, 0.00 % which seems strange.

Thankfully Porsche covered the cost to replace the Bank 1 filter, and we are now monitoring this vehicles oil ash levels going forward.

So the final report Cayman 718 GTS 2022

K211 Particulate filter bank 1, soot load calculated 0.4 %
K212 Particulate filter bank 2, soot load calculated 0.4 %
K221 Particulate filter bank 1, soot load measured 2.7 %
K222 Particulate filter bank 2, soot load measured 3.1 %
K230 Particulate, oil ash load calculated 5.1 %
K231 Particulate filter bank 1, oil ash load measured 6.3%
K232 Particulate filter bank 2, oil ash load measured 1.2 %
K241 Particulate filter bank 1, installation test diagnosis value 64.3 %
K242 Particulate filter bank 2, installation test diagnosis value 56.9%
K251 Particulate filter bank 1, differential pressure current value 0.81 hPa.

Well this report looks a lot better, we have readings in both soot calculated and measured values, we also have a reading in the K230 Particulate, oil ash load calculated of 5.1 %, funny if you deduct 1.2 from 6.3 you get 5.1, which is something new. We have always said a measured value can go up or down, its the calculated value that does the job.

We also have readings in K241, and K242 diagnostic values, which again is something new, we have seen this again on a new 4.0 GTS, but on other used 4.0 vehicles we have found no readings at all, we are trying to find out what it means. It could be nothing to do with our problem, but you never know.
Unfortunately we can not confirm that these readings were present on our 2.0 and 2.5 cars when they were new.

The funny thing about all our 2019 718 cars, that have had new modified filters fitted, is the oil ash levels coming back seem to be around 42% to 64%, could there be some kind of connection with the diagnostic values we see above.

But one thing for sure we are not getting any GPF issues with the 4.0 engines, and the data they provide looks a lot better.

Any feedback on this post would be greatly appreciated, we now have 100,000 views on this subject on our Forum.

Regards
Dave

 

[BrianJ]

Fascinating detail Dave, clearly presented. Amazing piece of work. As a matter of interest, which engine was it in the 991.2?

 

[Cyclemotor1958]

Hi BrianJ
Its a 3.0 GTS
Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Well its been a busy week so far

Ive been contacted by three 718 owners with GPF issues so far this week.

We are still waiting for Porsche and the dealers to come back to us with a new plan on how to deal with the oil ash % coming back on the cars fitted with the new modified filters.

More and more parts are being fitted to these cars in an attempt to fix this oil ash % issue.

Its unbelievable that the Dealers and Porsche are still insisting that these GPF,s are full of Ash, and the 100% is a true measurement of Ash inside the filter.

The parts that have been fitted, include modified GPF filters, AOS, Turbos and even new engines.

These parts have been fitted because they all can affect the Ash content in a GPF Filter, by allowing oil into the combustion chamber. Remember 90% of ASH is created from burnt engine oil.

The sad reality is, we have never found any Ash in these filters to have caused this issue, and even more surprising no high soot volumes either.

Both of which if were present, would be recorded in the differential pressure sensor readings, again its not happening, but it should be.

And after 2.5 years of asking dealers for exhaust back pressure checks to be carried out as part of the diagnostic tests, this is still not happening.

WHY NOT

Hopefully now with all these cars that have had modified filters replaced, and the fault is still present. We should not be getting any reports from owners saying the Dealer is insisting they need to spend 8K to replace the GPF when they have the DTC P242F present.

We would now expect that Porsche Readings Technical department would have sent out a note to the Dealers to carry out further checks to establish the back pressure situation, before they fit a new filter, thats not required.

We will be instructing any owner of a 718 with GPF issues, to go directly to a Porsche main Dealer, to get them to confirm the oil ash fault, and report it to Porsche Head office.

Afterall this fault was confirmed by Porsche Readings Technical department last year on one of our vehicles as a manufacturing defect.

Will keep you informed of our progress as we go along.

We currently have 101,000 views on this subject.

Dave

 

[Wrightrubber]

Hi Dave
Were the three 718 owners that contacted you this week all 2019MY and 2.0 Litre?
Regards
Mark

 

[911hillclimber]

Strikes me that Porsche anywhere do not have a fix, maybe not even an understanding of why the system on '19 cars have this serious glitch.
If this is true, then they are lost, have no solution that fixes the issue, so will give no info.

I still think the filter supplier(s) must be pushing back any claims now the removed filters are back in Germany if they make it that far.

Is this a UK spec car issue or more global?

When will you be in a position to collate fresh evidence and forward to Porsche GB and the Factory to add pressure?

As time goes by these '2019' cars will get a dark cloud over them and values will drop hard.

Can I add you and the people involved on this side of the fence are doing a really great job of this! Top marks from me.

 

[Oldbiddy]

As time goes by these '2019' cars will get a dark cloud over them and values will drop hard.

Precisely. That's exactly why I sold my 2020 Cayman (poisoned by association) and kissed Porsche farewell for ever whilst I still had a chance of getting a fair deal for my car.

 

[Cyclemotor1958]

Hi Mark, and 911Hillclimber,

Without Prejudice

Yes we have two 2019 2.0 cars, and one 2020 2.0 car.

We are waiting to see what response we get from these new owners, and others out there, if the response is not what we would expect then we will certainly push on.

The sad reality is that I have been involved with lots of these faulty cars that have had new GPF filters fitted, and the Oil Ash % has come back, lets not forget its not real.

Because of this, the owners have sold these cars, lost a lot of money, lost confidence with the dealers and the brand, and sadly are not driving Porsches anymore.

I have a detailed database to support this.

Hopefully Porsche will see sense and stop ignoring this major issue on their cars.

Dave

 

[AndrewT]

Dave,
I'm not a Porsche owner but I've followed this thread with interest.

Apologies if this has already been mentioned and forgotten by me but have you, or anyone except Porsche, cut open a supposedly blocked GPF filter to verify by how much it is blocked, if at all, or is this not technically possible? I assume that if an owner has paid for a GPF to be replaced they are entitled to keep the old one?

Keep up the good work.

 

[Cyclemotor1958]

Hi AndrewT

Without prejudice

Thankfully all our cars that had new GPFs fitted were covered under some kind of goodwill policy from Porsche, thats always been appreciated, even if we had to insist they changed their policy, on out of warranty claims.

We have had quite a few of our cars checked for any inaccuracies on the differential pressure sensor readings, most were spot on compared to the vehicles data.

This confirmed early on in our investigations that the GPF filters were not blocked.

We have never seen a high enough sensor reading to initiate an active regeneration, which is also confirmed by the DTC soot load high code, P2463 and the regeneration code 26740 never been present on any of our faulty cars.

We are now in a situation that Porsche have endevered to try and fix this issue and obviously spent alot of time and money, which is an indication that they feel that they have now some responsibility.

At the moment we have a situation that when a new filter is fitted, they manage to get the system to record a zero reading in the measured oil ash K231 section of the GPF report.

Unfortunately is doesn't stay at zero very long, and comes back with with figures that don't make any sense, the highest we have seen was at 78% and this was yesterday.

If you ask Google this question

Can motor vehicle manufacturers be liable if the gpf system on their cars are reporting incorrect values in the emission system.

This is what comes back in various forms

Motor vehicle manufacturers can be liable if their GPF system reports incorrect emissions values, especially if it's due to a defect, misleading advertising, or a failure to comply with environmental standards. This liability can result in fines for the manufacturer, and consumers may have a right to a remedy such as a repair, price reduction, or refund, according to EU legislation and UK consumer law.

Manufacturer liability

• Defects: Manufacturers are responsible for ensuring their products are free from defects that cause them to not be of "satisfactory quality". Incorrectly reporting emissions values can be seen as a defect that affects the car's performance and environmental compliance.
• Misleading advertising: If manufacturers make claims about emissions that are not true, this can lead to liability. Consumers can argue the car is not of satisfactory quality if actual emissions significantly exceed the advertised values, according to UK Parliament.
• Failure to comply with standards: Manufacturers are liable if their vehicles don't meet the required environmental and safety standards. Regulatory bodies can impose fines on manufacturers who fail to meet their CO₂ targets.
• Actionable consumer claims: Consumers can make claims for a breach of contract if the car's emissions are not as expected. If the issue cannot be fixed, they may be entitled to a price reduction or refund, according to EU legislation.

What to do if you have a problem

• Contact the manufacturer's authorized dealer: If you suspect a problem, an authorized dealer can examine the vehicle, says GOV.UK.
• Contact the manufacturer directly: If the dealer is unhelpful, you can report the issue to the manufacturer directly.
• Report to authorities: You can report a vehicle manufacturer to the relevant authorities if you think they are breaking the law by selling unsafe or illegal vehicles or parts, according to GOV.UK.

We will continue to appreciate the help that as been given by Porsche and their dealers when one of our cars presents the fault code P242F oil ash % exceeded.

We need the reassurance from Porsche that this will continue till they come up with a solution.

One thing thats come out of all this work that has been done over the last 2.5 years is that these cars are well loved.

To many of our cars have been sold because of this fault, its a real shame because they have all said, they never wanted to sell their cars and would have still been driving them today.

Fingers crossed


Dave

 

[Paul-718gts]

After speaking to Dave today it’s very clear that the Brand still appear to be ignoring this issue and for some reason hiding behind the fact they are now trying to tell owners that even after putting on a brand new GPF having a reading of 48 to 55% full is normal ??? It smells of a desperate smoke and mirrors exercise.. to just try and hide from the real root cause which is clearly related to the elephant is the room..
SOFTWARE..
Just so we don’t forget I have reposted one of my last posts … which details the amount of work completed on my car which had just over 14k miles on it before I rejected it and handed it back to Porsche…

And even after all this work my understanding is that apparently 48% is consider normal by the Brand….

Without Prejudice

Well it’s been at least a month since I last posted and there has been a lot going on so I feel I owe you all an update.

Just as a recap the start of my GPF nightmare started over a year ago after the light we all fear came on after a days driving enjoying my car with my wife.

A week later I had the you need to pay £8 to £9k call to fix your car as the GPF is 100% full.

I am fortunate enough that my GTS Boxster is a 2nd car and only used at weekends for days out and weekends away which normally entails journeys of 40 to 100 miles each way minimum.
I had only had the car since March 2024 and driven around 1200 miles.

So after the normal 3 month arm wrestle my 1st exchange GPF was fitted and I insisted that I didn’t believe this was the root cause and wanted 4 further VAL tests completed over a period of a year which the OPC agreed too otherwise I was going to reject the car.(my car showed the GPF to be 78% full when I purchased it on a 2019 car with 11200 miles from new)

After 500 miles and me logging my journeys it went back in and was at 29% full… we agreed a further period of driving and 300 miles later in Jan 2025 it went back in and was at over 40%.

Like most people it had taken me a long time to find my perfect spec car and I just wanted it fixed.

So jumping forward to July 2025 my car was still in the OPC trying to be fixed after 7 months. I must say at this point the OPC have been fully supportive and we had regular calls and quite a few face to face interactions. I wouldn’t however have the same level of praise for Porsche GB Reading, and TBH there customer interaction and service levels don’t represent a premium brand in my opinion/experience.

Sadly I have now thrown in the towel and rejected my car but continue my journey with Porsche in a 2021 Boxster GTS 4.0..

My old car is still not fixed and as far as I am aware been trailered off to Reading for further diagnosis and testing.

So in summary the following work was completed in the last year.

3 x replacement GPF(2 brand new/1 exchange)
2 x Differential pressure sensors
1 x DME (Computer/Car Brains)
1 x Oil separator
1 x engine strip down and check
1 x replacement turbo
1 x replacement engine

But sadly no software investigations as far as I am aware.

I am sure there are other bits I have missed and as well as a number of live road VAl tests completed.

Lessons to be learnt -
Work with your OPC - unfortunately it feels to me like they have their hands tied and have to follow what they are told to do.. they have all the responsibility and unfortunately none of the power.

Before you buy any modern car don’t just ask about FSH, ask for the VAL report and check the GPF or even DPF report.. if you feel it’s too high compared to the mileage walk away..
I am no expert but based on my experiences my rule of thumb is 1% ash fill for every 1000 miles.

Please feel free to ask questions I will try and help and support and share my knowledge and experience.

On a final note to the Club and your lack of support for you members, for whatever reason…..

Very disappointing and could try a lot harder…

 

[Paul-718gts]

Me again - these are the pictures of the 3rd GPF that was fitted and according to the VAL report over 50% full… appreciated you can’t see inside the GPF but you would expect to see some signs off the soot that is then converted to Ash during the regen process..???

 

[911hillclimber]

Interesting inset picture.
If i were the manufacturer of the filters and got that back as a warrantee claim from Porsche I would test and send it back to them with the 'all-clear' report.

Love to see that one cut open with a bandsaw.