Cayman 718 GPF Failure

[Wrightrubber]

Hi Dave
It will be interesting to see what Porsche Technical say about the 2023MY car, as this is still under the manufacturers warranty.
Regards
Mark

 

[Cyclemotor1958]

Hi Mark,
Yes it will be interesting on how this will play out, we will be following this case with great interest.
Thanks for your post

Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Sorry its been a while since I Iast posted, we have been waiting for cars going back into Dealers for their oil ash % levels checked.

This week we have 2 cars going back in, after they had new filters fitted at the beginning of this year, under warranty.

Fingers crossed, we hope to find no Ash present, will let you know as we go along.

Thanks for all your views again, we are now at 72K

Regards

Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Following on from my last post, both cars have been in this week, these cars had new modified GPF filters fitted within the last 4 months, and the oil ash % levels have been rechecked.

We recorded 54% and 47%, this information as now been sent to Porsche Technical for their attention.

When we look back at another 4 previous vehicles that have had new modified filters fitted, we recorded the following oil ash % readings.

42, 48, 64, 55.

Hopefully Porsche Reading Technical will have all this information on all these cars, which clearly now confirms that replacing the original filter, without confirming the actual existence of Ash is pointless.

To date, we have had no dealer carry out our request for a GPF back pressure check to be carried out on any of our faulty vehicles.

Also we have evidence that if a successful regeneration reset on these cars is carried out, and the oil ash value shows 0.00 %, if its then checked again, within 500 miles it comes back, usually around 50% on average.

Hopefully now the Dealers will not be asking us to find the money to replace a faulty GPF, when the DTC code P242F presents itself, because it clearly is not causing this issue.

Its taken us, over 2 years to get to this position, but by not needing to replace such an expensive exhaust, it really takes the pressure off.

We just need to look somewhere else, and finally sort this out.

We will be waiting in anticipation from our Dealer Technical Requests regarding this situation.

Dave

 

[Paul-718gts]

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…

 

[911hillclimber]

Sobering result.
7 months and no fix that works and that mechanical list is massive in terms of cost and time which I presume the OPC took.
I'm surprised you have stayed with the type of car and the brand in general and hope your future experiences will be happy.
What a saga.
I also presume the PCGB are poor because the factory are ignoring them and the issue.
Refreshing to read the OPC involved has been on your side.

 

[Scrounger]

I think the disappointing thing is that PCGB haven't posted anything here for some time, even if it were to report that they've had nothing back from Porsche GB or AG.

As I've said before, Porsche AG will do nothing until the wider audience is made aware and it starts to affect new and used car sales.

Dan

 

[ianthow]

I think the disappointing thing is that PCGB haven't posted anything here for some time, even if it were to report that they've had nothing back from Porsche GB or AG.

Spot on Dan. They did feature the issue in PP, but short of mentioning the differential pressure testing that showed the filters were NOT blocked.

 

[BrianJ]

I am amazed that this doesn't seem to have hit the motoring media somehow. I get that many owners won't want this to happen because if Porsche don't step up and fix it they will no doubt see a hit to residual values. However, if the resulting clamour were to result in positive and restorative reputational action from Porsche (ie a fix, like the centre lock wheels and other examples), then the market would soon respond. The market is gradually learning, with adverts starting to appear for early 718s specifically mentioning that they don't have GPFs. The fact that this is mentioned will result in at least some potential buyers asking what that's all about - and it's not just the noise they make.

 

[Scrounger]

Totally agree Brian.

Nothing worse than a manufacturer burying its head in the sand....cough, cough, Volkswagen.

Dan

 

[Greenman986S]

Totally agree Brian.

Nothing worse than a manufacturer burying its head in the sand....cough, cough, Volkswagen.

Dan

The apple doesn't fall far from the tree....

 

[911hillclimber]

I can see another IMS/bore score/ crank seal conversation soon kicking off.
I don't think that lot bothered Porsche in Germany at all.

 

[JohnCRS]

As someone who has been part of this from the beginning, working with Dave and also getting the original article in Porsche Post, I guess I should put a Cayman Register and PCGB perspective on this, albeit that it is my personal opinion and not 'sanctioned' by the Club.

This all started over two years ago with a CEL light coming on and the dealers were trying to charge £7-9k to turn it off. So what has been achieved through Dave's work?
- there is now no reason any owner should accept this diagnosis and we can help them work through this. Dave has saved members £thousands.
- the GPF fault is the result of a problem elsewhere, probably in the software algorithms. GPF's don't 'block' themselves.
- there is enough publicity on here and the related forums like Piston Heads to think that anyone who still hands over their hard earned cash for a new GPF is daft!
- we will move through this stage as dealers realise they will be rebuffed.
- if anyone is willing to be identified on here, asking for help because they have received such a diagnosis there is no problem with naming the OPC providing that it is restricted to being factual, supportable and 'unemotional'.

Summary: there are a relatively small number of cars out there that may throw up a P242F error code. We know that the OPC diagnosis is incorrect and can help owners push back against a costly GPF replacement. That is a significant win in my book.

But, of course, it would be good to get to the bottom of this and have Porsche confirm what is really going on. Just so we know!

We know that the GPF, AOS and other components have been upgraded during the period from 2019. We also have a body of evidence to support the fact that these are not the problem in terms of the ash load:
- replacing these components may be a reprieve but in some cases, such as Paul's, the dealers do this and still can't complete a fix. We also believe that the problem will recur in other cars that have been ‘fixed’.
- the fact that Porsche are still issuing different instructions suggests that they do not feel they have a complete solution to offer. My understanding is that the document was a letter, not a technical bulletin, again pointing to uncertainty at Porsche.
- we do not know why this affects some, but not all, cars in this 2019 period of production.

Dave has pointed at the software and the related hardware (sensors etc.) as being at the root of the problem almost from the start. This is based on:
- the VAL reports producing unbelievable results
- the inability of the dealers to reset the software after replacing the hardware.
- and finally Paul's experience where, having stripped the engine, replacing virtually everything that can be replaced, they are now pulling the car back to the centre and doing a deal.

Porsche GB are stonewalling us over this, and doing it successfully. They simply do not respond to the club, their customers or even the OPC's. It is a numbers game. Porsche has no reason or incentive to do anything other than deal with this matter on a case by case basis. Being generous we might find 30 owners willing to share their stories in public. We might get more by 'advertising' for owners to step up. But most won't want the hassle, just a working car. A decent OPC sells over 30 cars a month. These Caymans would be 0.01% of Porsche production in 2025. (The VW emissions case affected 11 million vehicles.) In Porsche terms this GPF issue is a minor blip. They have dealt with much bigger issues in the past - PDF gearboxes where owners had to buy new ones instead of getting the fault repaired (Still the case today) - wheels falling off centre lock cars (they could not ignore that one) - the myriad issues affecting the electric vehicles - 997 engines grenading on cars that had barely covered 50,000 miles. The list goes on. Unpalatable as it might be, in our world this 'GPF' is a big deal. In Porsche world it is in the inbox of a junior technician. The same applies to trying to attract the attention of the media. It only affected a certain series of cars produced in 2019. It is yesterday's headline in a world where Caymans and Boxsters continue to be rated as highly reliable.

It is at this point that I start speculating, based on the fact that I cannot believe that Porsche do not know where the problem lies. Such ignorance is inconceivable. So, consider the hypothesis that they know the answer, that there is a fault in the calibration of sensors and, or, the programming of the ECU etc. and the controlling of emissions. This fault is enough to trigger the P242F error code in some circumstances. All these systems are subject to TUV and global certifications and any changes would require re-certification and potentially cost $lots and $lots. Better to keep the lid on it, acknowledge nothing and let OPC's handle the relatively small number of cases, most of which can be dealt with somehow.

So, where does that leave us?
1. we do have knowledge and leverage to help those who are affected by the P242F error code.
2. we do not have leverage to make Porsche explain the issue and offer a solution through a technical bulletin.

From a register and club perspective I will take 1 above as having done our job for members. I am not happy about 2 but I think we have to live with it unless we can see a negative impact on those members that we can get hold of.

Therefore, we keep going, support our members, publicise as much as possible on here and elsewhere and see what, if anything, developes.

 

[Wrightrubber]

Without Prejudice

Paul, I am pleased you managed to get out of that car but I am somewhat surprised you have taken on another 718 and from the same dealer, you said the dealer has been very supportive, is this the same dealer that never returned your calls and you had to constantly chase for updates on the progress, the way they have treated you over the past 7 months, I don't think I would have been as forgiving!! What gives you the confidence that your new 718 doesn't or will not suffer the same issue, Porsche clearly cannot or are not willing to sort the problem, we have seen later cars (later than 2019 models) with the same problem.
Anyway I started this whole issue with the very first post but thankfully I am out of the loop now having sold my car.
Enjoy your new car Paul, I hope everything goes well, best wishes.
Mark

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Thanks Paul for your post, it really confirms what we have been saying for the last 2 years, the Gpf filter was never the problem, and this now finally shows no matter what parts you fit to these cars to get the oil ash % to behave, your wasting your time.

There has been a major miss diagnosis on this fault from the start, and the recent internal memo that came out on March detailing diagnostic checks to be carried out if the P242F oil ash load to high was present, definitely confirmed this.

Also the memo confirms that a new GPF had been modified to prevent this issue, and all vehicles with a production date later than December 2019 should already have the modified GPF fitted.

The one diagnostic check that would have stopped this situation from continuing, a GPF back pressure check was excluded on the memo, WHY.

The good news now is that the dealers can not blame the drivers of these cars, for putting in the wrong engine oil, or not driving them correctly, and the huge cost of replacing the GPF isn't necessary.

We have cars going back in for further checks now, after the new GPF filters have been fitted, and hopefully the dealers will be putting pressure on Porsche Technical to get this issue finally sorted.

Afterall its really embarrassing for them, now that the cats out of the bag.

The only thing left now is the software, which we have said many times is easy to adjust to correct this fault once and for all.

We now have 74K views on this subject, this amount of attention on a vehicle fault on our Porsche Club Forum is breaking records, never ever been seen before.

Fingers crossed, we are nearly there.

Sorry John, I hadn't seen your post, before I started mine, but might as well send it out.

Dave

 

[Paul-718gts]

Hi John,

Completely agree on both your root cause speculation and the method in which the Brand is managing this issue..

As you say it’s a numbers games and far cheaper to deal with the few than resolve the majority.

 

[dpoynton]

I have got punch drunk trying to get up to speed on this disturbing matter.

Could someone please post a resume of where things stand, eg, which 718 cars definitely DO NOT suffer from the GPF issue (all 18 reg and prior plus certain 68 dates?) and therefore which years we need to be careful about.
What have Porsche GB Reading publicly stated on the matter and what support will they give.
Any other salient points.

Thanks
David

 

[ianthow]

I have got punch drunk trying to get up to speed on this disturbing matter.

Could someone please post a resume of where things stand, eg, which 718 cars definitely DO NOT suffer from the GPF issue (all 18 reg and prior plus certain 68 dates?) and therefore which years we need to be careful about.
What have Porsche GB Reading publicly stated on the matter and what support will they give.
Any other salient points.

Thanks
David

Date of registration will not help due to variable time lapse between manufacture and registration. The model year (MY) is probably more relevant. This is coded in the 10th digit of the VIN. For MY 2019 cars, the code letter is K. Production for MY 2019 will have begun in the second half of 2018 so some 68 plate cars could be MY 2019. Assuming GPFs were first fitted for MY 2019, any car with an MY code earlier than K should be OK.

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Well, what a day yesterday on our forum, just shows the interest on our forum when we put on some news.

Speaking of news, just had some this morning, we have a vehicle that's just had its original GPF filter reset to zero by a Dealer.

We asked for the oil ash % level to be rechecked after completing 300 miles, this was checked, and we now have 89%.

When you read the last paragraph of the internal Porsche memo regarding the OPF (GPF) procedure, it says in some cases the OPF can be recovered if a regeneration is carried out.

This regeneration is how they try to re set the OPF to zero. If this fails, the instruction is to replace the OPF and the vehicle retested.

It seems clear now that if a GPF % retest is carried out after a short mileage is covered, the software re calculates a new %.

This calculation is way off scale and doesn't represent the actual oil ash loading of the GPF, so it can not be believed.

On all of our cars that have had new modified filters fitted, all of them now have an oil ash % readings that make no sense at all.

What we also find is that there are no soot values recorded either, which we have seen on almost all of our faulty cars, which again is not right.

And the fact that we have no record of any driver of our 718 vehicle's reporting a ( Regenerate particle filter see Drivers Manual ) message on their dashboards, must confirm that something is not quite right with our software.

You would expect someone out there to have seen this message.

When this message appears on the dashboard, it leaves 2 trouble codes, P2463 Particulate filter soot load high, and 26740 Particulate filter Regeneration needed.

I am sure if Porsche Technical looked back at all the GPF replacement information they have, they would see this issue.

I wonder what was happening in 2019 when the Dealers were seeing our P242F oil ash load code coming on, and the need for Porsche to bring out a modified filter to prevent this from happening. And its odd that this issue should really show itself 6 years on.

Again, this was confirmed in the last paragraph on the internal memo.

We have a condition on these cars at the moment, that one minute we have a high oil ash% value that puts a light on, then the next minute its gone after a soot regeneration is carried out, and then the oil ash % comes back.

Thankfully, we all know now that these figures are not correct, and you can not regenerate ASH if it's real.

So all the hard work has now been carried out, eliminating the hardware, we just need to look at our software, bearing in mind that most of the figures you see on the GPF report are measured or calculated by an algorithm.

Dave

 

[JohnCRS]

To summarise, as requested by DPoynton above. This issue started with the first cars to be fitted with the GPF, model year 2019 cars. Most of the cases dealt with are from that period. We have seen later cars affected, and also different Porsche models, but so far these are exceptions and I do believe that these exceptions do not create a rule. We suspect there may be more cases coming through but do not have the numbers to support it (yet!)

So: Pre-2019, non GPF cars are fine
MY 2019, = higher risk
MY 2020, = lower risk
MY2021 and beyond = low risk (i.e. there is a higher chance of something else going wrong, rather than the GPF)

These cars consistently score well in reliability tests, so it is important to keep this in context. For every car that has had a GPF issue, there are tens, or even hundreds, of cars running fine. The reason this has become such a big issue is because some members faced a very large (£7-£9k) charge for something that was not covered under warranty. If Porsche had been able to fix it without charge, we would hardly know of it.

If I were in the market for a Cayman or Boxster 718 2.0 or 2.5 ltr car I would be wary of MY2019 model year. For all years I would ask for a VAL report and expect lower than, say, 60% ash load. I would then ask for the GPF to be included in the warranty. I would only buy through an OPC or Porsche specialist who is aware of the potential problem. On this basis, if I found the car I wanted, even a 2019 one, I would go ahead

It seems that 4.0 ltr cars do not suffer from this issue. (I know of one case that could be a GPF problem, but I know of two cases where engines have been replaced for other reasons.) I would be happy buying a 4.0 ltr.

I think the margins involved in the measurement of the ash load are incredibly small. Sensors and all otherparts of the drive train are manufactured to tolerances. It is possible that in some cases all the tolerances and measurements are such that they hit the predetermined level and trigger the error code. In most cases this does not happen but, very exceptionally, you get a situation like Paul's which becomes a lost cause.

Dave has done a fantastic amount of work on this issue and is happy to continue to assist members who are having GPF problems. Through his efforts we believe we know what we are dealing with and know how to help members avoid the big bills OPC's still try to charge. Thank yoou Dave. We will continue with this and, if Porsche technical would like to reach out to us, we really would like to know what 718 owners are facing.