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Cayman 718 GPF Failure

Morning all,

We have just hit 190K views on our forum, which is brilliant, just shows the interest in our posts.

The reason I didn't answer 718touring's question regarding build dates, is because we have seen this theoretical ash build up on cars later than 2019.

We have even seen it on two 2019 991 cars, which we have also been involved in, and are still monitoring now, after the new filters have been fitted.

Last year I was contacted by a 2023 Cayman T owner who was worried about his car, we arranged an ash % check at his local Dealer.

Before that appointment I meet up with the owner and we checked his AOS reading just to see were it was, it was running between 30 to 35 inches of water tested with a manometer.

This is ok because I managed to get a reading from a newly fitted AOS on another Cayman 718, so we knew that his reading was ok.

The first ash reading was taken at 10,700 miles and it was 14.12%.

We took the second reading at 16,506 miles and unbelievably it was at 50.59%.

The ash% had increased by 36.4% over the last 5,800 miles.

While the car was in the workshop I suggested to the owner that he should ask the technician who was showing him the ash reading, did his car have the adaptation function to reset the differential pressure sensor and the GPF.

The technician apparently laughed and said no mate these cars don't have this adaptation.

With that news the owner sold his car shortly after, and we keep in touch often, because he is following our posts with great interest, his car was a Euro 6AP model.

So let's get back to the internal memo that Porsche sent out last year that covered this ash % issue.

The technicians are directed to first look at the fault code P242F (oil ash load to high) if it is present, then look in the GPF data and check the specific soot calculated and measured load, along with the ash calculated and measured load information.

It then explains the 100% fault threshold of the P242F code, and what can cause the ash particals, that form ash, such as additives in the engine oil.

It then goes on to explain that several causes of the high ash load have been found across various vehicles, therefore to prevent repeat issues it is important to check all possible causes of high ash load before proceeding with any repair.

The checks cover a cylinder leakage test, checking inlet and exhaust for signs of oil entering the cylinders, leaks from the AOS, turbocharger and valve stem seals, and even checks on the turbocharger actuator.

The final check was to make sure the GPF differential pressure sensor was checked for correct functionality, ensuring the pipes to the sensor are not blocked or restricted.

The Service history had to be checked to make sure that the correct low Ash oil had been used on all services.

It then went on to say, if no causes can be located, and the above checks are all confirmed as OK, then in some cases the GPF can be recovered by attempting a regeneration to see if the ash load is able to be reset. If it doesn't reset the GPF should be replaced and the vehicle should be retested.

The new GPF's (982254400AF) have been modified to prevent this issue.

The memo even says if there are any issues outside of this model year range or any further questions please submit a PRMS ticket or email directly to the author of the memo.

Quite a few months ago I made several attempts to contact Porsche regarding this internal memo, and at the same time I contacted Porsche Stuttgart to see if they could help me with this issue.

I did this because some of our Dealers were not supporting our owners with this fault, and certainly not getting approval from Porsche to replace these filters, they say will fix this issue.

I was even given a Porsche case number so I could contact Porsche Technical directly, again I made several attempts to contact them, but they have to date not come back to me.

Its a real shame because all I wanted to do was discuss with Porsche Technical why the manufacturer intructions did not include a physical manometer pressure test to show the actual back pressure in the GPF.

So this is my interpretation of this memo.

Under standard warranty rules, if a GPF or DPF filter is physically blocked with ash or soot due to how the vehicle has been driven, or how its been serviced, its classed as a wear and tear issue.

If our Dealers were allowed to carry out a simple back pressure check and they found zero back pressure, which also confirmed the low reading given by the differential pressure sensor, then the wear and tear argument completely collapses.

The failure immediately shifts to a software defect, which Porsche is obligated to cover under warranty.

With all our evidence regarding the ash % coming back on all of our 13 cars that had new modified filters fitted, it confirms 100% that this is not a GPF component issue, its software.

And the fact that adaptations to reset the differential pressure sensor and GPF ash values are not in these DME'S
firmware, once again confirms its definitely software.

And carring out a soot regeneration to try and reset an ash problem is absolutely ridiculous, if ash was physically present in these GPF filters it couldn't be removed by regeneration.

We push on

Dave
 
Hi Guys & Girls

Just another reminder when your EML light comes on with a warning message saying.

Engine Control fault Consult dealer Driving permitted, if they find the DTC code P242F present, please don't put yourself under any pressure.

BECAUSE THERE ISN'T ANY.

You may be told that your particulate filter bank 1 oil ash measured reading K231 is at 100% which put the light on.

And you may be told you need a new GPF filter.

YOU DON'T

If you can convince your Dealer or garage to check the GPF for back pressure, they definitely will not find any that would support a blocked GPF filter either with soot or Ash.

Talking about soot, you will always definitely not find any soot present when your GPF is showing a reading of 100% ash.

You can then ask the Dealer to show you the internal Porsche memo they have, that explains what to do when the DTC P242F is present on your car.

If you could get sight of this memo, you will see that it gives clear instructions to carry out a soot regeneration to try and reset your ash % reading.

It also gives information on items to be checked before the attempted regeneration is carried out, that could contribute to the ash buildup in the GPF.

THESE EXTENSIVE CHECKS WOULD NOT BE REQUIRED IF THE BACK PRESSURE CHECK WAS CARRIED OUT FIRST.

It goes on to say if the regeneration doesn't reset your ash % reading, then the next step is to replace your supposedly blocked GPF filter with a modified filter that was brought out to fix this very same issue.

Which is confirmed in the memo, its in the last paragraph at the bottom of the page.

Sounds very simply, but in practice its very difficult for some reason.

Below are two photos from the same car taken recently, one showing a GPF report from a Porsche PWIS diagnostic tester showing the 100% oil ash measured value K231, and it also shows no soot present.

And the other photo shows the actual back pressure reading taken at the same time from the GPF supple pipe to the differential pressure sensor.

NO PRESSURE AT ALL

I know people will say Iam repeating myself again, but if anybody now with this problem comes on to this forum for help. They will have an updated plan of what to do going forward, which is based on over three years of research into this problem.

Dave
 

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Does the new filter design work?
That is the owner can drive off into the distance free of any worry this will return?

Is there proof the new ‘2019’ replacement filter has failed ( light on) before reasonable miles covered, say 60k miles?
Or, does it fail much the same time/ miles of the car’s original?

Have any 2020 or younger cars failed with a dash light on?
Finally, if the car goes into an MoT and the light is present the car fails. What does the owner do?
 
Hi 911Hillclimber

We are monitoring quite a few of these cars with the new modified GPF's fitted.

All the cars have ash readings that are not acceptable for the mileages covered.

Our highest reading at the moment is 79% over 5 thousand miles, we have another one that had over 60% of ash when the owner picked it up from just having the new filter fitted.

They insisted the Dealer gave them the GPF readings before they left the garage, we have proof of this on record.

The others are generally over 50 %, and let's not forget Paul's car, and all the parts that were fitted trying to reduce his ash reading, that was I believe around 50%.

These cars are filling up with Ash, (that isn't there) alot quicker than from new.

Because the adaptation function to zero the differential pressure sensor and the GPF values are not there, the algorithm software is totally confused.

This is what must have happened to the cars in the first year of production, for them to bring out a modified filter with a new part number, and was fitted to December 2019 cars onwards.

Obviously we know that these modified filters were not the cause of this problem.

Any changes to emission control hardware or software by any motor vehicle manufacturer has to be approved by the emission bodies that sanctioned the original cars.

So way back in 2019 these modified GPF filters will have been authorised to be replaced, its just a shame that on all of our cars they don't seem to fix this issue.

We know are original GPF filters have always dealt with the soot because the tailpipes are always light grey in colour.

If you compare them with a 981 tailpipe you can really see the difference these GPF filters make.

We just need the software sorting, thats all.

Regarding the Mot, all they need to do is drive the car, and the light will go out eventually, then when its out, take it in for the mot test.

Remember there is very little ash in these cars even after all this time, its all make believe.

There is absolutely no reason to sell these cars because of this fault, we just need to get Porsche to introduce a back pressure check, and then they can sort out the real problem.

Dave
 
Hi Guys & Girls

Some good news for a change, we have had a another GPF replaced F.O.C by a Porsche Dealer down south today which brings our total to 18 cars.

Which is good news, but we are still fighting to get more of our faulty 718 cars authorised. For some reason our Dealers are still saying that Porsche will not allow them to carry out a simple back pressure check as part of their diagnosis of this fault.

This is absolutely ridiculous that this simple check was omitted from the internal memo instructing the Dealer technicians on what to do when the ash code P242F presented itself.

What it did say was to check the GPF differential pressure sensor for correct functionality ensuring the pipes to the differential pressure sensor are not blocked or restricted.

So on every one of these cars that have had this fault, their technicians have seen a differential pressure reading that did not support a blocked filter condition.

Common sense would suggest a further diagnostic test to check the very low differential pressure sensor reading that are always present when these filters show this ash load at 100%.

Afterall a faulty sensor could easily indicate a blocked filter, when in fact it wasn't.

Omitting the back pressure check wasn't left out by accident, it was done on purpose.

We have pushed on about this back-pressure check for the last 3.5 years and its still being ignored.

By confirming no back pressure is present takes away the need to replace a very expensive exhaust component, why are they not looking at this.

Thankfully we are looking at this, and all the information we have collated over the last 3.5 years proves beyond any doubt that these modified GPF filters are not the source of this problem and have never been in all the cars that we have dealt with.

I know some people may say why are you pushing to get these filters replaced knowing it will not fix these cars.

Thats simple, its their diagnosis, not ours but when these filters are changed and authorised by Porsche it confirms that they have accepted responsibility for this fault on these vehicles. And they will have to accept further responsibility going forward when these ash levels come back, which at the moment they are doing.

We push on

Dave
 
18, what a good number!
When the OPC changes the filter, paid for or free I presume the light goes out, and for a long time, even over a year?
I presume the repair carries a warrantee, thus OPC carry that obligation until the end of the cover?

As proven, the light comes on at some random time due to sensor action not part failure, so possibly the OPC then has a repeated obligation to replace?

Any plans to find a new 'door' to open Fortress Porsche to get some reliable action?
 
Morning 911Hillclimber,

From all the information we have received from our owners who have had the new modified filters replaced, they carry out a soot regeneration on the new filter and spend a lot of time road testing these cars to get a zero ash reading which doesn't stay at zero for long.

Typically our owners are reporting that lots of fuel is used and lots of miles have been covered after the replacement of these filters.

We have documented cases of two cars that had ash levels over 50% after the filters were replaced, which was found when the customers asked to see the GPF data on their cars before they took collection.

Both our owners challenged this ash returning, and they were both told by the dealers that Porsche Technical said it was acceptable providing it didn't continue to increase beyond 50 %.

To back this up, we challenged a Porsche Dealer last year on one of our cars that had covered only 1600 miles after a new filter was fitted and it had 47% of ash recorded.

We asked the dealer to contact Porsche and ask them what would be the expected ash reading immediately after a new modified GPF was fitted.

They confirmed in writing that it could be anywhere between 0% and 50%, they said this below.

The value should stay steady and not be constantly increasing. If the value continues to increase, then this would indicate that the cause of the GPF high ash load has not been attended to and further investigation is required.

We have this statement documented on file.

This is because our cars do not have the adaptation function in the firmware to carry out a simple ash reset on a brand new GPF filter, and more worring no adaptation function regarding the replacement of the differential pressure sensor.

Regarding the warranty on these new filters, we have struggled to get a definitive answer on this subject.

We have seen a GPF filter replaced using the Porsche extended warranty because the AOS supposedly took out the GPF, this should definitely have the two year parts warranty.

Buts its all nonsense, these filters are not faulty, you only have to look at the tailpipes, no soot, if the substrate fails in any way, soot will be found in the tailpipes.

If we go back to the memo, the first sentence says.

The customer complains of the EML light on the dash and in some cases reduced power output from the vehicle.

We have had no reports of reduced power on any of our cars with this fault, no running issues at all, only one DTC P242F ash load to high.

When you look at the GPF data in the cars memory it always records zero soot values, on a filter thats showing an ash load value of 100%.
It then goes on to explain how ash can accumulate in the particulate filter.

Its obvious that this ash loading value is not real, because where as all the soot gone on a filter thats blocked up with ash.

The differential pressure sensor is not seeing any pressure build up in these filters, its the software algorithm thats giving a false reading.

And its continuing to give false readings after the new modified GPF filter is replaced.

Regarding future plans, yes we are constantly looking at other avenues but we cannot disclose these at this time.


Dave
 
Hi following on from my last post, enclose this video of a chap re learning a differential pressure sensor on a Porsche Macan diesel.

Begs the question why is this not on our cars

Dave




 
Hi Dave
18 vehicles that have had the GPF replaced F.O.C is brilliant, well done!! That has saved the owners over £170K!!! (Not really a fabrication is it AW_GTS!!)
It begs the question, Porsche say it's not covered under the extended warranty, so why are they replacing them F.O.C? It's not a goodwill gesture as there is no goodwill from Porsche! I believe that they know it's been a problem from day one and all the information you have collated backs this up and is slowly backing them into a corner so the best option for them is to replace them F.O.C. to try and help the issue go away!!!
Just my opinion anyway!
Keep up the good work.
Regards
Mark
 
Thanks Mark.

Your opinion matters to me, you started us off over 3.5 years ago and its been quite a journey.

You will remember when your ash came back on your new filter you asked the Service Manager at your Porsche Dealership what happens if this happens again.

You were told they wouldn't be paying again, they knew then that this wasn't a permanent fix replacing these filters, because they refused our requests for a back pressure check way back then.

Around that time I purchased a few manometers to test the AOS and yours was the first car we tested, it was ok.

We then sent out these manometers on the next batch of cars, and found all had similar readings and confirmed the ash levels were not caused by the AOS.

They were adamant that your driving style had caused the premature ash accumulation, they couldn't blame the lack of Porsche service history because your car had full Porsche Service history.

We eventually managed to get them to give you your GPF data and when we checked the information provided it was quite obvious that it didn't make any sense at all.

They changed their mind, and agreed to replace it free of charge.

We went on to ask all the other owners with this same issue to get the GPF reports and this proved very successful in changing their mind.

Then along came the internal memo, that says it all, the fact that they had modified this GPF in the first year of production confirmed what we had said, nothing to do with driving style, lack of Porsche service history and certainly nothing to with what oil was put in the cars.

Its taken us along time to get to this point, its taken lots of conversations with owners who had been struggling with their Dealers who were blaming them for this ash level problem, only to find there is no ash.

And the fact that these new filters fill up with Ash so quickly again confirms this.

Let's just think about all the owners who were told they needed a new GPF filter, and couldn't afford to replace it, so they sold their cars.

Totally let down by Porsche and their Dealer network, its all coming to the surface now, and somebody is going to have some explaining to do.

There is no excuse for this behaviour and how these Porsche customers have been treated and that memo confirms it all.

Cheers Mark

Dave
 
It is simply poor electronic/ programming engineering then, the filters are fine, the sensors see a different position and the light pops up.
Inside VAG there must be a huge experience of these things, obviously not tapped into way back thus the car cannot be sorted.
I still can’t grasp that Porsche thought the fault was the filter itself, the engineers must have read the data just as you have collated.
The reaction from them is really poor ill informed or simply just to be ignored as lots of others want a Porsche, current and recent customers are disposable.
Arrogance?
 
Morning all,


Just to give everyone an update on my blocked GPF issue and the ongoing discussions with the OPC.


The good news is that, with all the information shared on the forums, the support from Dave, and the detailed case I put forward to the OPC, Porsche agreed to carry out the checks outlined in the infamous memo. The OPC couldn’t/wouldn’t share the results with me, but they did confirm that Porsche had approved the replacement of the GPF — phew! That was around two weeks ago.


When I collected the car yesterday, I asked whether they had managed to identify the root cause of the failure that had resulted in the blocked GPF fault. Unfortunately, they couldn’t comment. However, at my request, they did provide me with the diagnostic report, which showed the oil ash level at 0%. 👍


So, after driving just 30 miles, I’ve run my own diagnostic check today — and the oil ash level is already showing 3.41%. 😡☹️


If that rate continues, it looks like the filter could supposedly be showing as blocked again within around 1,000 miles.


Needless to say, I’ll be heading back to the OPC on Monday to discuss this further. I’ll keep you all updated.

IMG_0278.jpeg
 

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