Cayman 718 GPF Failure
- Thread starter Wrightrubber
- Start date
Hi Dan
I have a plan going forward but at the moment I can not discuss it, but hopefully its a good plan and if we are lucky it could be very beneficial to us all.
That's why I am asking 2019 718 owners to get their ASH levels checked, the more cars we can find with this fault the more it will help our plan.
We need to stop these cars being sold into the trade because of the excessive cost of this repair thats certainly not required.
Its up to the owners of these cars to help us push on, Ive said this before there is nothing out there that can equal the driving experience that these cars give you guys.
Its always been worth the fight to keep these cars with their owners.
Porsche and their Dealers need to support us and stop this issue being bigger than it should be.
Iam not an expert in software, but other models have had software changes along the way, why not your cars.
Regarding Porsche GB not getting in touch with us, if this proves to be the case, then they definitely don't care.
We have asked for help from the people who built these cars, the least we could expect is some help.
Dave
I have a plan going forward but at the moment I can not discuss it, but hopefully its a good plan and if we are lucky it could be very beneficial to us all.
That's why I am asking 2019 718 owners to get their ASH levels checked, the more cars we can find with this fault the more it will help our plan.
We need to stop these cars being sold into the trade because of the excessive cost of this repair thats certainly not required.
Its up to the owners of these cars to help us push on, Ive said this before there is nothing out there that can equal the driving experience that these cars give you guys.
Its always been worth the fight to keep these cars with their owners.
Porsche and their Dealers need to support us and stop this issue being bigger than it should be.
Iam not an expert in software, but other models have had software changes along the way, why not your cars.
Regarding Porsche GB not getting in touch with us, if this proves to be the case, then they definitely don't care.
We have asked for help from the people who built these cars, the least we could expect is some help.
Dave
According to PP, Dr Wolfgang Porsche is still the Patron of our club - see https://en.wikipedia.org/wiki/Wolfgang_Porsche. You could write to him (a letter) at Porsche HQ. Might have an interesting reaction!
I’ve only just found this thread as I’m considering getting a 2019 2.0 718.
Can anyone summarise how common this fault is?
Can anyone summarise how common this fault is?
Hi Cayman _R_Gruppe
Would you be buying from a Porsche Dealer.
This makes a great difference if the car you are looking at has this issue.
If it is from a Dealer hopefully the car will have had its 111 point check for you to see, and you can also ask to see the GPF report showing the oil ash % reading.
You could always send this information to us to if you are unsure what you are looking at.
We have always expected that the Dealers would check these cars first before they sell them.
They could contact Porsche and Porsche could authorise the replacement modified GPF and it could be fitted before a new customer purchased the car.
Afterall the memo says that after December 2019 the modified GPF filter was fitted to these cars.
So why is it that the Dealers try and charge their customers for a modified filter that should have been fitted within the 3 year manufactures warranty period.
And what makes it even worse is the GPF filter is a major emission part on these cars, so it should have be replaced if the ash % was far to high for the mileage covered and the age of the car.
I won't mention the simple GPF back pressure check that could have been done to confirm the supposedly blocked filter, because Iam just repeating myself.
On the 3rd car I dealt with, that had this issue, we managed to get the GPF replaced F.O.C, and a written conformation from Porsche Reading that this GPF fault was indeed a manufacturing defect.
The owner sadly sold this car because the Ash came back, but said I could use this information on the forum, we have a case number to support this statement.
So I would definitely recommend buying a 718 car from a Porsche Dealer because they are well aware of this issue, and have the means to rectify the fault before a new customer purchases the car.
Regards
Dave
Would you be buying from a Porsche Dealer.
This makes a great difference if the car you are looking at has this issue.
If it is from a Dealer hopefully the car will have had its 111 point check for you to see, and you can also ask to see the GPF report showing the oil ash % reading.
You could always send this information to us to if you are unsure what you are looking at.
We have always expected that the Dealers would check these cars first before they sell them.
They could contact Porsche and Porsche could authorise the replacement modified GPF and it could be fitted before a new customer purchased the car.
Afterall the memo says that after December 2019 the modified GPF filter was fitted to these cars.
So why is it that the Dealers try and charge their customers for a modified filter that should have been fitted within the 3 year manufactures warranty period.
And what makes it even worse is the GPF filter is a major emission part on these cars, so it should have be replaced if the ash % was far to high for the mileage covered and the age of the car.
I won't mention the simple GPF back pressure check that could have been done to confirm the supposedly blocked filter, because Iam just repeating myself.
On the 3rd car I dealt with, that had this issue, we managed to get the GPF replaced F.O.C, and a written conformation from Porsche Reading that this GPF fault was indeed a manufacturing defect.
The owner sadly sold this car because the Ash came back, but said I could use this information on the forum, we have a case number to support this statement.
So I would definitely recommend buying a 718 car from a Porsche Dealer because they are well aware of this issue, and have the means to rectify the fault before a new customer purchases the car.
Regards
Dave
Ive just had a thought, surley if these cars required a modified OPF to fix this issue as explained in the memo, WHY weren't all the affected cars called back in that were sold before December 2019.
It would have been an easy check for the Dealers to carry out, the first service would be a good time to have a look..
And if the Ash% level was to high, the modified filter could have been fitted under the manufacturer's Warranty.
The reason I say this is, we have an owner with a vehicle that had a reading of over 75% at his first service, at 11,713 miles.
Whats Interesting is on the same day another reading was taken showing an exhaust temperature of 620.60 degrees centigrade.
Which could be a possible regeneration attempt to reset the ash value.
This unfortunately didn't make any difference to that Ash reading of 75.69%.
If this was the case, then this GPF should have been replaced under the manufacturer's warranty, unfortunately it wasn't and the customer was never informed of this situation on his car.
So his warning light came on, with a P242F code 100% Ash recorded, and quess what, its not covered under warranty and he as to pay.
This customer bought this car from new, we have been asking Porsche to sort this issue out for a very long time.
And we are still waiting, you will see that later in the cars service history he didn't use the Dealer, they are saying because of this he has to pay, something to do with spark plugs, which are required every 4 years, or 40K.
Why should he pay for a manufacturing defect on his car that was present on the 1st year service.
The Dealer and Porsche should be ashamed of themselves for treating this customer in this way.
We managed to get this GPF information, but its been a real battle, but thankfully it was worth it.
We will keep you posted on this case
Regards
David
It would have been an easy check for the Dealers to carry out, the first service would be a good time to have a look..
And if the Ash% level was to high, the modified filter could have been fitted under the manufacturer's Warranty.
The reason I say this is, we have an owner with a vehicle that had a reading of over 75% at his first service, at 11,713 miles.
Whats Interesting is on the same day another reading was taken showing an exhaust temperature of 620.60 degrees centigrade.
Which could be a possible regeneration attempt to reset the ash value.
This unfortunately didn't make any difference to that Ash reading of 75.69%.
If this was the case, then this GPF should have been replaced under the manufacturer's warranty, unfortunately it wasn't and the customer was never informed of this situation on his car.
So his warning light came on, with a P242F code 100% Ash recorded, and quess what, its not covered under warranty and he as to pay.
This customer bought this car from new, we have been asking Porsche to sort this issue out for a very long time.
And we are still waiting, you will see that later in the cars service history he didn't use the Dealer, they are saying because of this he has to pay, something to do with spark plugs, which are required every 4 years, or 40K.
Why should he pay for a manufacturing defect on his car that was present on the 1st year service.
The Dealer and Porsche should be ashamed of themselves for treating this customer in this way.
We managed to get this GPF information, but its been a real battle, but thankfully it was worth it.
We will keep you posted on this case
Regards
David
Attachments
My opinion of Porsche continues to sink..
on a related note please, when one of these cars pass out of the cover period( if there is or was one) whatever will the independent outlets do with that dash light?
on a related note please, when one of these cars pass out of the cover period( if there is or was one) whatever will the independent outlets do with that dash light?
Greenman986S
PCGB Member
A moot point given the issue isn't covered anyway
Morning,
We have been looking at another one of our models fitted with a GPF filter, from the same model year. Specifically looking to see if these cars have the facility to adapt the differential pressure sensor, and the GPF filter after replacement.
Without the software capability to adapt and relearn when these components are replaced its no wonder the ash levels are incorrect and don't make any sense at all.
When you look at the GPF data and see an high Ash % value, with very little soot values present, and a differential pressure sensor value that is virtually none existent, it needs to be investigated.
So to check the data you are seeing you would need to connect a pressure reading device to the input pipe from the GPF to the sensor and read the actual GPF pressure before it goes through the sensor and is absorbed by the algorithm.
If you find that the actual GPF pressure is high enough to support the Ash % figure you are seeing, then its either blocked with soot, or ash, and the sensor is giving false information.
On the other hand if you find that the actual GPF pressure is as low as the figure you are seeing on the data, then the GPF cannot be blocked with anything.
And as we know from the data we have seen on our cars, very little soot is present at all when these GPF filters put on this Ash code P242F oil ash load to high.
And to back this up we have never see a soot regeneration warning on our dashboards, on all the cars that presented this code.
You would expect that a filter that is supposedly filling up with Ash, would at some point trigger the the soot regeneration light and warning message.
So after this simple check was carried out and no back pressure was found in the GPF, and the differential pressure sensor reading was indeed correct, you could then carry out the adaptation of the GPF to reset the system so the algorithm would know exactly where it is.
Just like we do on our diesel vehicles, on these cars we clean out the soot, after checking the pressure in the DPF, and then carry out the adaptation by confirming the DPF as been replaced.
A simple procedure, thats worked for years, you cannot regenerate a DPF filter if its blocked with soot, you have to clean it out first and confirm its not blocked.
The instruction from our Dealers is to try a soot regeneration in the the hope that it will rest the GPF ash level to zero, because if it doesn't Porsche Technical say the GPF needs to be replaced with a modified part that was manufactured to prevent this very same issue in late 2019.
Surely this most be an inherent design flaw in the software of these faulty cars and needs a software update. We have had 13 cars fitted with new modified GPF filters and unfortunatly this high ash % issue as not gone away.
So the only way we can move forward is to insist that this back pressure check is carried out on these cars when this P242F code presents on our dashboards.
Up to now on everyone of our cars the Dealers have refused to do this check, even when we have offered to pay for it.
Why would they not do this simple check, whats the reason for this, it doesn't make any sense, and why are Porsche Technical not making them do the test.
This is why we wanted the chance to speak to Porsche Technical, and to ask this very same question, we have a case number, but has of today still no contact.
Its the 29th of May to day, exactly 3 years since we started on this project to highlight the major miss-diagnosis of this fault.
Dave
We have been looking at another one of our models fitted with a GPF filter, from the same model year. Specifically looking to see if these cars have the facility to adapt the differential pressure sensor, and the GPF filter after replacement.
Without the software capability to adapt and relearn when these components are replaced its no wonder the ash levels are incorrect and don't make any sense at all.
When you look at the GPF data and see an high Ash % value, with very little soot values present, and a differential pressure sensor value that is virtually none existent, it needs to be investigated.
So to check the data you are seeing you would need to connect a pressure reading device to the input pipe from the GPF to the sensor and read the actual GPF pressure before it goes through the sensor and is absorbed by the algorithm.
If you find that the actual GPF pressure is high enough to support the Ash % figure you are seeing, then its either blocked with soot, or ash, and the sensor is giving false information.
On the other hand if you find that the actual GPF pressure is as low as the figure you are seeing on the data, then the GPF cannot be blocked with anything.
And as we know from the data we have seen on our cars, very little soot is present at all when these GPF filters put on this Ash code P242F oil ash load to high.
And to back this up we have never see a soot regeneration warning on our dashboards, on all the cars that presented this code.
You would expect that a filter that is supposedly filling up with Ash, would at some point trigger the the soot regeneration light and warning message.
So after this simple check was carried out and no back pressure was found in the GPF, and the differential pressure sensor reading was indeed correct, you could then carry out the adaptation of the GPF to reset the system so the algorithm would know exactly where it is.
Just like we do on our diesel vehicles, on these cars we clean out the soot, after checking the pressure in the DPF, and then carry out the adaptation by confirming the DPF as been replaced.
A simple procedure, thats worked for years, you cannot regenerate a DPF filter if its blocked with soot, you have to clean it out first and confirm its not blocked.
The instruction from our Dealers is to try a soot regeneration in the the hope that it will rest the GPF ash level to zero, because if it doesn't Porsche Technical say the GPF needs to be replaced with a modified part that was manufactured to prevent this very same issue in late 2019.
Surely this most be an inherent design flaw in the software of these faulty cars and needs a software update. We have had 13 cars fitted with new modified GPF filters and unfortunatly this high ash % issue as not gone away.
So the only way we can move forward is to insist that this back pressure check is carried out on these cars when this P242F code presents on our dashboards.
Up to now on everyone of our cars the Dealers have refused to do this check, even when we have offered to pay for it.
Why would they not do this simple check, whats the reason for this, it doesn't make any sense, and why are Porsche Technical not making them do the test.
This is why we wanted the chance to speak to Porsche Technical, and to ask this very same question, we have a case number, but has of today still no contact.
Its the 29th of May to day, exactly 3 years since we started on this project to highlight the major miss-diagnosis of this fault.
Dave
Hi Dave
How did the guy (that asked for help on the 718 Forum) with a 991 that had both filters blocked get on, was this a 2019MY? any news on this one??
Regards
Mark
How did the guy (that asked for help on the 718 Forum) with a 991 that had both filters blocked get on, was this a 2019MY? any news on this one??
Regards
Mark
Hi Mark,
Yes it is a 2019 car, its showing an oil ash reading of 100% on both GPF filters, its at his Porsche Dealer.
He's waiting for his dealer to come back to him with an action plan.
If you remember we successful managed to get authorisation for one GPF filter on a 991 2019 last year, the GPF data on that car didn't make any sense at all, same has our cars.
Hopefully the Dealer will see that this is not normal, and not keep the customer waiting to long for authorisation from Porsche GB.
Fingers crossed
Dave
Yes it is a 2019 car, its showing an oil ash reading of 100% on both GPF filters, its at his Porsche Dealer.
He's waiting for his dealer to come back to him with an action plan.
If you remember we successful managed to get authorisation for one GPF filter on a 991 2019 last year, the GPF data on that car didn't make any sense at all, same has our cars.
Hopefully the Dealer will see that this is not normal, and not keep the customer waiting to long for authorisation from Porsche GB.
Fingers crossed
Dave
Morning Guys & Girls
Ive just been tidying out my workshop this morning looking for my exhaust back pressure tester.
If you get the ash load light on your dashboard and the code is P242F and your technician is telling you need a new modified GPF filter because yours is blocked.
Then please ask him or her if they have carried out a back pressure check using a tool like this one, I could always send them this tool if they don't have one.
Don't forget a blocked GPF with ash will have lots of back pressure, its just the same as if it was blocked with soot.
Dave
Ive just been tidying out my workshop this morning looking for my exhaust back pressure tester.
If you get the ash load light on your dashboard and the code is P242F and your technician is telling you need a new modified GPF filter because yours is blocked.
Then please ask him or her if they have carried out a back pressure check using a tool like this one, I could always send them this tool if they don't have one.
Don't forget a blocked GPF with ash will have lots of back pressure, its just the same as if it was blocked with soot.
Dave
Attachments
Hi everybody
I thought it was time to list our GPF fault working progress at the moment.
1. From last year we are still trying get the Dealer and Porsche to authorise replacing the GPF that they have said is faulty. This is the car that had a 75% ash reading when it went for its first Dealer service at 11,713 miles in 2021.
2. We have three 718 cars that had new modified filters fitted last year, which are having regular ash % level checks. We managed to convince Porsche and their Dealers that the GPF data they provided didn't make any sense at all, and they where fitted F.O.C.
All these cars have now ash percentage levels that are far to high, bearing in mind the time since replacement, and the mileage covered. Two have around 50%, and the other one was at over 70% the last time we checked.
On average our cars have taken 6 years to hit this 100% oil ash measured value, some of these cars have left the workshop with over 50 % of ash already in the software after the new modified filter was fitted.
3. We have two more 718 cars that recently had the 100% oil ash load with the warning light on.
We are currently waiting for news on what the Dealer and Porsche are going to do.
4. We have another 5 cars out there that are running around with the warning light coming on and off, one of them is a 2021 car.
5. We also have a 2019 991 with both filters showing the 100% oil ash reading, and again we are waiting for news from the Dealer, we have asked for the GPF data.
Has you know we are asking for back pressure checks to be carried out once we have the diagnosis from the Dealers that the GPF has to be replaced because its full of ash.
Over three years in and we have been refused every time we asked this question.
Normally when a GPF, or DPF is blocked with soot or ash you would experience a loss of power, poor fuel economy, or even engine overheating symptoms, and definitely more warning lights on the dashboard.
Of course we have never had any of these symptoms on any of our cars, so this must be the reason whey they refuse to do the back pressure test.
How could all the Dealers who have been involved with all of our faulty cars refuse to do this test, its bloody ridiculous that this simple test can not be carried out.
The Dealers have a responsibility to their customers to diagnose this fault correctly, Porsche have a responsibility to make sure they do.
So whats their real reason for not doing a back pressure check.
We are in contact with all these people just to make sure they aware of our commitment to get to the bottom of this problem.
But more importantly we are trying to help keep these owners in their cars, because has we have said before there is nothing out there that equals the driving experience you get when you own one of these cars.
We will continue to update you regarding the above vehicles has soon as we get some answers.
We currently have 171K views on this subject on our Forum, so we have alot of interest out there on how things are progressing.
Thanks for your support
Dave
I thought it was time to list our GPF fault working progress at the moment.
1. From last year we are still trying get the Dealer and Porsche to authorise replacing the GPF that they have said is faulty. This is the car that had a 75% ash reading when it went for its first Dealer service at 11,713 miles in 2021.
2. We have three 718 cars that had new modified filters fitted last year, which are having regular ash % level checks. We managed to convince Porsche and their Dealers that the GPF data they provided didn't make any sense at all, and they where fitted F.O.C.
All these cars have now ash percentage levels that are far to high, bearing in mind the time since replacement, and the mileage covered. Two have around 50%, and the other one was at over 70% the last time we checked.
On average our cars have taken 6 years to hit this 100% oil ash measured value, some of these cars have left the workshop with over 50 % of ash already in the software after the new modified filter was fitted.
3. We have two more 718 cars that recently had the 100% oil ash load with the warning light on.
We are currently waiting for news on what the Dealer and Porsche are going to do.
4. We have another 5 cars out there that are running around with the warning light coming on and off, one of them is a 2021 car.
5. We also have a 2019 991 with both filters showing the 100% oil ash reading, and again we are waiting for news from the Dealer, we have asked for the GPF data.
Has you know we are asking for back pressure checks to be carried out once we have the diagnosis from the Dealers that the GPF has to be replaced because its full of ash.
Over three years in and we have been refused every time we asked this question.
Normally when a GPF, or DPF is blocked with soot or ash you would experience a loss of power, poor fuel economy, or even engine overheating symptoms, and definitely more warning lights on the dashboard.
Of course we have never had any of these symptoms on any of our cars, so this must be the reason whey they refuse to do the back pressure test.
How could all the Dealers who have been involved with all of our faulty cars refuse to do this test, its bloody ridiculous that this simple test can not be carried out.
The Dealers have a responsibility to their customers to diagnose this fault correctly, Porsche have a responsibility to make sure they do.
So whats their real reason for not doing a back pressure check.
We are in contact with all these people just to make sure they aware of our commitment to get to the bottom of this problem.
But more importantly we are trying to help keep these owners in their cars, because has we have said before there is nothing out there that equals the driving experience you get when you own one of these cars.
We will continue to update you regarding the above vehicles has soon as we get some answers.
We currently have 171K views on this subject on our Forum, so we have alot of interest out there on how things are progressing.
Thanks for your support
Dave
Hi Guys and Girls
We continue to look at all the facts we have regarding the information we are getting from Porsche concerning this oil ash % issue.
If we look deeper into the checking information contained in the Porsche memo titled.
1. ENGINE- 718: 982 OPF- P242F 00F0A5 Particulate filter-ash load too high.
It says 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. These include completing cylinder leakage checks to ensure oil is not entering the cylinder, checks of the intake and exhaust for signs of excessive oil build up which could be a result of a leak from the oil separators, turbocharger or valve stem seals. It is also important to check the operation of the turbocharger actuator to ensure this is functioning correctly and to check the OPF differential pressure sensor for the correct functionality ensuring the pipes to the differential pressure sensor are not blocked or restricted.
The service history of the vehicle should be checked and it confirmed that the correct low Ash oil has been used in all services.
Regarding the turbocharger actuator function its well known that the actuator pin can seize causing high and low boost issues, there has been a bulletin out on this fault for quite a while.
The Dealers have been replacing the complete turbo when this happens, but in some cases this isn't required because you can free off the pin, drill out the connecting arm using a 10mm drill bit, and all is ok, then just clear the code.
The memo mentions this but doesn't mention anything to do with a code being present, which got me thinking what has this got to do with ash accumulation.
So a bit more research, and this is what I found, if you ask the question can the Porsche DTC code P0234 cause ash accumulation, this is what came back.
The P0234 overboost code does not cause ash accumulation, instead, the exact reverse is true—if your GPF accumulates excessive soot or ash, the resulting severe exhaust backpressure can disrupt the turbocharger dynamics and trigger a P0234 Overboost condition.The relationship between your GPF ash levels and the overboost code is detailed below.
1. How a Blocked GPF Causes P0234 Overboost.
The Pressure Back-Up:
A GPF heavily restricted by ash acts like a physical plug in your exhaust pipe.
Turbo Disruption:
For a turbocharger to control its boost pressure correctly, exhaust gas must be able to escape freely through the wastegate when it opens.
The Overboost Trigger:
If the exhaust gas cannot flow out through the blocked GPF fast enough, a wave of high pressure builds up right behind the turbo turbine wheel. This abnormal exhaust dynamic prevents the wastegate from efficiently bypassing gas, causing the turbo to spin too fast and spike the intake manifold pressure. The engine computer (DME) detects this sudden spike and throws the P0234 code.
2. The Danger of Ash vs. Soot in a Petrol Filter.
According to Porsche Technical Bulletins (via NHTSA), petrol filters manage two types of buildup very differently.
Soot (Combustible):
Petrol exhaust runs significantly hotter than diesel exhaust. Your Porsche burns off soot automatically during normal driving (passive regeneration).
Ash (Permanent):
Ash is non-combustible material composed of metal compounds left behind after your engine burns tiny amounts of motor oil. It cannot be burned off.
The Motor Oil Culprit:
Porsche warns that using the wrong engine oil drastically accelerates ash buildup in a GPF. Petrol Porsches with GPFs explicitly require low-ash oils—typically specified as Porsche C20, C30, or C40 standards (rather than the older A40 petrol oil). If unapproved oil was used during previous servicing, it will directly cause permanent ash accumulation.
How to Identify the Root CauseTo determine if your P0234 overboost is caused by a blocked GPF or a traditional mechanical fault (like a seized wastegate actuator or failing N75 solenoid valve).
Check the GPF Live Data:
Connect a Porsche-compatible diagnostic tool (like a PIWIS, iCarsoft, or Launch) to the OBD2 port. Look at the DME live data parameters for "GPF Ash Mass" and "Exhaust Differential Pressure." If the pressure differential across the filter is excessively high under a load, the filter is physically blocked.
Isolate the Wastegate Actuators:
If the GPF ash mass reads normal, the overboost is likely a physical mechanical fault. Modern petrol Porsches use electronic or vacuum-operated wastegate actuators that can seize up due to heat cycling.
Could it be that our DME sees incorrect information saying that the turbo exhaust gas cannot flow out through the supposedly blocked GPF, affecting the intake manifold pressure and this condition would suggest to the DME that the filter is blocked because a restriction would definitely affect the intake manifold data.
We then have this situation where the DME presumes the GPF is blocked and ignores the exceptionally low differential pressure sensor readings we are seeing.
So if a back pressure check is not carried out, then our Dealers and Porsche believe that the GPF is actually blocked with ash, which is a big mistake, in fact its a £9K miss diagnosis mistake.
If you think about this the DME is monitoring the slow reduction of intake manifold pressure and is calculating a measured ASH percentage value thats clearly not correct, it should be a calculated value.
A measured value can go up and down, if Ash was actually present in these GPF filters it cannot reduce, because ash is generally incombustible.
This is confirmed when a new modified GPF filter is fitted, and the ash comes back. This is because without the adaptation of the filter being carried out, the DME as no idea where its base value is.
We know our cars do not have this adaptation function, and they should have.
This adaptation is a basic emission control requirement and its just being ignored and it can't be, its been ignored since 2019.
Sorry for going on, but its all evidence that this fault was present on these cars within the first year of production, we have a car that had a substantial ash buildup just over a year old, with very low mileage.
Just read this memo again, it explains it all, and you can draw your own conclusions.
Any feedback would be greatly appreciated, and by the way, still no contact from Porsche Technical.
I have given up trying to contact them, they clearly are not interested in all the work we have done through the Porsche Club.
Which is a great shame, afterall we are trying to save them money and trying to keep their Porsche 718 owners in these cars.
Dave.
We continue to look at all the facts we have regarding the information we are getting from Porsche concerning this oil ash % issue.
If we look deeper into the checking information contained in the Porsche memo titled.
1. ENGINE- 718: 982 OPF- P242F 00F0A5 Particulate filter-ash load too high.
It says 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. These include completing cylinder leakage checks to ensure oil is not entering the cylinder, checks of the intake and exhaust for signs of excessive oil build up which could be a result of a leak from the oil separators, turbocharger or valve stem seals. It is also important to check the operation of the turbocharger actuator to ensure this is functioning correctly and to check the OPF differential pressure sensor for the correct functionality ensuring the pipes to the differential pressure sensor are not blocked or restricted.
The service history of the vehicle should be checked and it confirmed that the correct low Ash oil has been used in all services.
Regarding the turbocharger actuator function its well known that the actuator pin can seize causing high and low boost issues, there has been a bulletin out on this fault for quite a while.
The Dealers have been replacing the complete turbo when this happens, but in some cases this isn't required because you can free off the pin, drill out the connecting arm using a 10mm drill bit, and all is ok, then just clear the code.
The memo mentions this but doesn't mention anything to do with a code being present, which got me thinking what has this got to do with ash accumulation.
So a bit more research, and this is what I found, if you ask the question can the Porsche DTC code P0234 cause ash accumulation, this is what came back.
The P0234 overboost code does not cause ash accumulation, instead, the exact reverse is true—if your GPF accumulates excessive soot or ash, the resulting severe exhaust backpressure can disrupt the turbocharger dynamics and trigger a P0234 Overboost condition.The relationship between your GPF ash levels and the overboost code is detailed below.
1. How a Blocked GPF Causes P0234 Overboost.
The Pressure Back-Up:
A GPF heavily restricted by ash acts like a physical plug in your exhaust pipe.
Turbo Disruption:
For a turbocharger to control its boost pressure correctly, exhaust gas must be able to escape freely through the wastegate when it opens.
The Overboost Trigger:
If the exhaust gas cannot flow out through the blocked GPF fast enough, a wave of high pressure builds up right behind the turbo turbine wheel. This abnormal exhaust dynamic prevents the wastegate from efficiently bypassing gas, causing the turbo to spin too fast and spike the intake manifold pressure. The engine computer (DME) detects this sudden spike and throws the P0234 code.
2. The Danger of Ash vs. Soot in a Petrol Filter.
According to Porsche Technical Bulletins (via NHTSA), petrol filters manage two types of buildup very differently.
Soot (Combustible):
Petrol exhaust runs significantly hotter than diesel exhaust. Your Porsche burns off soot automatically during normal driving (passive regeneration).
Ash (Permanent):
Ash is non-combustible material composed of metal compounds left behind after your engine burns tiny amounts of motor oil. It cannot be burned off.
The Motor Oil Culprit:
Porsche warns that using the wrong engine oil drastically accelerates ash buildup in a GPF. Petrol Porsches with GPFs explicitly require low-ash oils—typically specified as Porsche C20, C30, or C40 standards (rather than the older A40 petrol oil). If unapproved oil was used during previous servicing, it will directly cause permanent ash accumulation.
How to Identify the Root CauseTo determine if your P0234 overboost is caused by a blocked GPF or a traditional mechanical fault (like a seized wastegate actuator or failing N75 solenoid valve).
Check the GPF Live Data:
Connect a Porsche-compatible diagnostic tool (like a PIWIS, iCarsoft, or Launch) to the OBD2 port. Look at the DME live data parameters for "GPF Ash Mass" and "Exhaust Differential Pressure." If the pressure differential across the filter is excessively high under a load, the filter is physically blocked.
Isolate the Wastegate Actuators:
If the GPF ash mass reads normal, the overboost is likely a physical mechanical fault. Modern petrol Porsches use electronic or vacuum-operated wastegate actuators that can seize up due to heat cycling.
Could it be that our DME sees incorrect information saying that the turbo exhaust gas cannot flow out through the supposedly blocked GPF, affecting the intake manifold pressure and this condition would suggest to the DME that the filter is blocked because a restriction would definitely affect the intake manifold data.
We then have this situation where the DME presumes the GPF is blocked and ignores the exceptionally low differential pressure sensor readings we are seeing.
So if a back pressure check is not carried out, then our Dealers and Porsche believe that the GPF is actually blocked with ash, which is a big mistake, in fact its a £9K miss diagnosis mistake.
If you think about this the DME is monitoring the slow reduction of intake manifold pressure and is calculating a measured ASH percentage value thats clearly not correct, it should be a calculated value.
A measured value can go up and down, if Ash was actually present in these GPF filters it cannot reduce, because ash is generally incombustible.
This is confirmed when a new modified GPF filter is fitted, and the ash comes back. This is because without the adaptation of the filter being carried out, the DME as no idea where its base value is.
We know our cars do not have this adaptation function, and they should have.
This adaptation is a basic emission control requirement and its just being ignored and it can't be, its been ignored since 2019.
Sorry for going on, but its all evidence that this fault was present on these cars within the first year of production, we have a car that had a substantial ash buildup just over a year old, with very low mileage.
Just read this memo again, it explains it all, and you can draw your own conclusions.
Any feedback would be greatly appreciated, and by the way, still no contact from Porsche Technical.
I have given up trying to contact them, they clearly are not interested in all the work we have done through the Porsche Club.
Which is a great shame, afterall we are trying to save them money and trying to keep their Porsche 718 owners in these cars.
Dave.
Attachments
Hi Dave
Whatever the cause, it is so concerning that Porsche Technical refuse to engage while the dealers continue to misdiagnose the issue and want to charge owners £9500 to replace a GPF filter that isn't full!!!
They call themselves a 'Premium Brand,' Porsche GmbH, Porsche GB and the Porsche Dealers, should be ashamed but their shear arrogance won't let them.
Regards
Mark
Whatever the cause, it is so concerning that Porsche Technical refuse to engage while the dealers continue to misdiagnose the issue and want to charge owners £9500 to replace a GPF filter that isn't full!!!
They call themselves a 'Premium Brand,' Porsche GmbH, Porsche GB and the Porsche Dealers, should be ashamed but their shear arrogance won't let them.
Regards
Mark
Hi Mark
Thanks for your feedback, Ive always suspected that this fault could possibly have been miss diagnosed right from the beginning.
The fact that a modified filter was introduced within the first year confirms this, so this means this issue was dealt with within the manufacturer's 3 year warranty period.
Six years on we are seeing this same issue, on cars that have low mileages compared to the age of their cars.
The Dealers and Porsche can not turn round now and admit they knew all about this issue, after they used the reason for this failure to be driving style and the wrong engine oil used.
Let's not forget all those owners who sold their cars because of this fault and what made it worse was the Dealers and Porsche's reluctance to help fix this issue that they were well aware off.
These owners not only lost confidence with the Dealers, they lost confidence with Porsche.
We came along 3 years ago and upset the applecart, we looked at the GPF data, and realised that it made no sense at all. We then confronted the Dealers and Porsche Technical and in 14 cases we managed to get them to cover the cost of replacing these supposedly faulty filters.
They even went to the expense of replacing all these parts on Paul's car last year to try and resolve an Ash value that came back after all these parts were fitted below.
2 x GPF filters
2 x differential pressure sensors
1 x AOS
1 xDME
I x engine removal stripped down looking for internal signs of oil consumption, none found.
They then replaced that engine with a brand new exchange engine
And finally a new turbo, we haven't made any of this up its well documented.
We have the original registration number and chassis number and Paul's account of his journey trying to get his car fixed.
In the end the Dealer concerned admitted they couldn't fix his car, even after Porsche Technical Reading came to look at the car, before the turbo was fitted.
The Dealer bought back the car and Paul purchased a 4.0 GTS.
They tried their best to fix this car and failed, at no point was a back pressure check done, even after we asked for it to be done.
So using the excuse that its how the car is driven, lack of service history, wrong engine oil used, is absolutely incorrect.
Paul's car confirms this, so we are back to the facts which are these.
1. Why can't the GPF filter ash measured values be reset without carrying out a soot regeneration if there is no visible back pressure recorded by the differential pressure sensor in the data.
2. Why is there no Adaptation function on these cars, we can't even adapt the differential pressure sensors never mind the new GPf filters.
3. Why are the cars that have had new modified filters fitted, coming back with unexplained ash values that come back so quickly after the filter is replaced.
4. Why have we seen this ash 100% fault on 2019 991 vehicles, we have dealt with one last year and are currently involved with another one at the moment.
So many questions, not enough answers.
Dave
Thanks for your feedback, Ive always suspected that this fault could possibly have been miss diagnosed right from the beginning.
The fact that a modified filter was introduced within the first year confirms this, so this means this issue was dealt with within the manufacturer's 3 year warranty period.
Six years on we are seeing this same issue, on cars that have low mileages compared to the age of their cars.
The Dealers and Porsche can not turn round now and admit they knew all about this issue, after they used the reason for this failure to be driving style and the wrong engine oil used.
Let's not forget all those owners who sold their cars because of this fault and what made it worse was the Dealers and Porsche's reluctance to help fix this issue that they were well aware off.
These owners not only lost confidence with the Dealers, they lost confidence with Porsche.
We came along 3 years ago and upset the applecart, we looked at the GPF data, and realised that it made no sense at all. We then confronted the Dealers and Porsche Technical and in 14 cases we managed to get them to cover the cost of replacing these supposedly faulty filters.
They even went to the expense of replacing all these parts on Paul's car last year to try and resolve an Ash value that came back after all these parts were fitted below.
2 x GPF filters
2 x differential pressure sensors
1 x AOS
1 xDME
I x engine removal stripped down looking for internal signs of oil consumption, none found.
They then replaced that engine with a brand new exchange engine
And finally a new turbo, we haven't made any of this up its well documented.
We have the original registration number and chassis number and Paul's account of his journey trying to get his car fixed.
In the end the Dealer concerned admitted they couldn't fix his car, even after Porsche Technical Reading came to look at the car, before the turbo was fitted.
The Dealer bought back the car and Paul purchased a 4.0 GTS.
They tried their best to fix this car and failed, at no point was a back pressure check done, even after we asked for it to be done.
So using the excuse that its how the car is driven, lack of service history, wrong engine oil used, is absolutely incorrect.
Paul's car confirms this, so we are back to the facts which are these.
1. Why can't the GPF filter ash measured values be reset without carrying out a soot regeneration if there is no visible back pressure recorded by the differential pressure sensor in the data.
2. Why is there no Adaptation function on these cars, we can't even adapt the differential pressure sensors never mind the new GPf filters.
3. Why are the cars that have had new modified filters fitted, coming back with unexplained ash values that come back so quickly after the filter is replaced.
4. Why have we seen this ash 100% fault on 2019 991 vehicles, we have dealt with one last year and are currently involved with another one at the moment.
So many questions, not enough answers.
Dave
Sorry everybody for repeating myself many, many times on this subject.
Ive always believed that if anybody who has this issue looked on our Porsche Club Forum and the 718 forum for help, they would see very quickly what current information we have managed to get, and whats actually happening right now.
We have 50 pages of information on our forum and it would take alot of time to read it all.
One thing we have proved is that repeating our claim that the GPF data is not right on these cars,has enabled us to change Porsche,s decision to charge some of our owners for this fault, 14 infact.
The problem we are having now is they have changed direction, and its taking us longer to convince them, its not the owners fault that has caused this issue.
We have always repeated our opinion that this is a manufacturing defect, which was confirmed in writing on one of our earlier cars, a few years ago.
The owner sold the car, because the ash came back, but gave us permission to use the information we gathered along the way.
The Porsche case number is 8000244324, perhaps Porsche could look again at the information they sent out.
Dave
Ive always believed that if anybody who has this issue looked on our Porsche Club Forum and the 718 forum for help, they would see very quickly what current information we have managed to get, and whats actually happening right now.
We have 50 pages of information on our forum and it would take alot of time to read it all.
One thing we have proved is that repeating our claim that the GPF data is not right on these cars,has enabled us to change Porsche,s decision to charge some of our owners for this fault, 14 infact.
The problem we are having now is they have changed direction, and its taking us longer to convince them, its not the owners fault that has caused this issue.
We have always repeated our opinion that this is a manufacturing defect, which was confirmed in writing on one of our earlier cars, a few years ago.
The owner sold the car, because the ash came back, but gave us permission to use the information we gathered along the way.
The Porsche case number is 8000244324, perhaps Porsche could look again at the information they sent out.
Dave
Posts made and opinions expressed are those of the individual forum members
Use of the Forum is subject to the Terms and Conditions
