Cayman 718 GPF Failure

[911hillclimber]

Good article from the USA above imho.
I have had acute AOS issues on my old skool 987.2 but on both component changes I've cut open the old AOS to find nothing ripped or failed, but lots of oil in the tubes to the intake which gives the HUGE plume of white smoke every now and then on cold start.

This has all but been eliminated by reducing the oil level in the engine, obviously as indicated on the dash board (bring back dipsticks).

My engine now runs a hot oil level at tick-over mid way between Max and Min. This has fixed the issue though I do every 3 months or so remove the AOS pipe and wash through with solvents, some oil, but very little. I have run this way for 4 years, set to this level at an oil change and never needs oil top-up (now 85K miles old).

The graduations on the dash are the same as the dipstick Max/Min markings on an ordinary dipstick.

My 1973 911 runs the very same level position used on the road and hillclimbing with no ill effects.

Just a thought in this perplexing scenario.
Looking forward to March Post and the reactions after.

 

[Cyclemotor1958]

Hi 911Hillclimber

Brilliant post, you are right the oil levels are wrong, nothing wrong with dip sticks.

When you look at AOS vacuum testing by using a manometer attached to the oil cap, with engine running, you get an accurate vacuum readings.

Enclose information used when I worked at my local Porsche independent Garage.

This information was supplied to me personally from a brilliant Porsche contact in America, 8 years ago.

Our cars are running above 30 H20 (inches of water), which is a lot, and on a recent 2018 718, that had white smoke on start up, the vacuum readings put the tester in error mode.
It went off scale, it's scale limit was 55 H20.

We are trying to get Porsche to give us the AOS testing vacuum data on these cars, but no contact as yet.

Enclose photos of my information mentioned above.

Regards
Dave

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Have a look at this, just checked the chassis numbers on all our affected cars / if the eleventh digit is an S then it was made in Stuttgart.

All our 2019 cars without exception came from Suttgart, could there be a connection.

Porsche Moving Cayman Production To Another Factory To Meet Demand For New 911 | Carscoops

Demand for the new 911 is so high, Porsche is clearing up capacity at its main factory

www.carscoops.com

Dave

 

[Paul-718gts]

Hi Dave,
Have we got all of the engines numbers for the 14 members cars, this may provide a commonality if parts like valve guides are failing causing the GPF to look like it’s full ? Or at least that’s what Porsche are currently thinking.

Looking at below the 4 cylinder engines were assembled at another plant and shipped to Stuttgart

 

[Scrounger]

Zuffenhausen is in Stuttgart.

Most, but not all, 718s were produced at the Stuttgart plant. I don't think there is a link there but looking deeper, is there a link in the build dates of the GPF/DPF or even the DME or sensor software/build dates?

Dan

 

[Paul-718gts]

Zuffenhausen is in Stuttgart.

Most, but not all, 718s were produced at the Stuttgart plant. I don't think there is a link there but looking deeper, is there a link in the build dates of the GPF/DPF or even the DME or sensor software/build dates?

Dan

Hi Dan,
I don’t believe there is a link with the GPF manufacturing date as my first one was reported full last July after approximately 12k and my second one is currently reading 47% full after 800 miles. Given there was 5 years between both being fitted I would be surprised if they was from the same batch.
Currently my car has been at the OPC for 6 weeks having lots of investigation work being completed and they have informed me it’s 100% not software related and have headed down the route of worn/faulty valve stems.
I am hoping to have an update early this week and potentially my car back at the end of this week.
My understanding is that there are several other cars that are on their second GPF also looking to go down this path.

Fingers crossed they have finally got to the root cause but only time will tell..

 

[Scrounger]

If that’s the case Paul then I’d be more inclined to look at engine build dates and/or valve stem batch numbers and see if there’s any link that way. The engine build dates would be the first option as this would indicate a manufacture date or batch of valve stems.

Somewhat clutching at straws but just another avenue to explore.

Dan

 

[ianthow]

Having followed this thread since inception, it seemed to have reached a point where it was established that the cars flagging errors with the GPF did not actually have a blocked GPF based on pressure differential readings, i.e. no ash build up, so no excess engine oil being burnt. Now we are looking for reasons for ash build up from excess oil consumption due to wear in valve guides/stems. Are there two scenarios here, or is this valve guide/stem issue a red herring that will simply confuse the issue of unnecessary replacement of GPFs?

 

[Cyclemotor1958]

Morning Guys & Girls

Without prejudice

Yesterday we had another Cayman 718 with a 100% oil ash level along with the usual DTC code P242F.

The garage wanted to carry out a regeneration of the filter to try and clear the ASH.

We all know that you cannot regenerate ASH if it's actually present in the filter, to confirm the ASH level a simple exhaust back pressure check should be carried out.

Remember in all our cases with GPF filters that where at 100%, the differential pressure sensor reading ways shows the opposite, no pressure at all ?.

This is what a dealer checked before a GPF filter was replaced last year on one of our cars, they where looking for signs of internal oil contamination which could accelerate SOOT and ASH loading.

NO MENTION OF AN EXHAUST BACK PRESSURE CHECK TO CONFIRM THE REPORTED MEASURED VALUE OF 100% OIL ASH WAS CORRECT.

Service history is complete and showing correct viscosity of oil used at each service.
(MOBIL 1 ESP 0w40).
Removed turbo intake pipe and inspected for excessive oil formation – none found, Turbo in good condition and oil seals within turbo not leaking.
Removed oil vent pipes from oil separator and checked oil misting. No defects found with oil separator.
Spark plugs removed and found no signs of excessive soot or oil contamination.
Compression test showing all cylinders over 9Bar. (All well within spec of 9.5:1 ).
This showing rings and compression correct and no defects.
No defects found on engine or ancillary components.
Cause of soot build up due to amount of short journeys and engine operations
Confirmed via VAL info;
Total engine starts = 003978
Operations at standstill = 00900
Operations between 0 and 3 miles = 01401
Engine runs between 0 and 10 min = 02196
Requires OPF filter replaced and advise driving car at operating temperature for longer periods in

This car went back in after covering only a 1,000 miles with the new filter, and the oil ash level was already at 45%.

THIS IS IMPOSSIBLE, BEARING IN MIND ALL THE ABOVE CHECKS THAT HAD BEEN CARRIED OUT WITH NO FAULTS FOUND PRIOR TO FITTING A NEW FILTER.

Surely we need to look at this measured oil ash value more closely, remember its part of a algorithm to run the emmision system on these cars.

We are now 100% confident that replacing these expensive GPF filters is not fixing these cars.

And the dealers need to stop upsetting our owners with a potential bill of 8K for an exhaust system that's not required.

And why after all this time are the dealers not checking for exhaust back pressure before they ring the customer.

We hear so many times from owners that they have been told by the dealers that their driving style is causing this issue, and it's not covered under warranty.

So bearing in mind we have never seen the soot regeneration warning light and message coming on our dashboards which should leave a DTC code P2463, and the difficulties the dealers are finding to try and fix these cars, this definitely puts these cars into a not fit for purpose category.

We hopefully will have some news soon regarding some tests we are carrying out regarding the relationship between the differential pressure sensor readings and the engine ECU.

Regards

Dave

 

[Paul-718gts]

Total engine starts = 003978
Operations at standstill = 00900
Operations between 0 and 3 miles = 01401
Engine runs between 0 and 10 min = 02196
Requires OPF filter replaced and advise driving car at operating temperature for longer periods in

———————————————————

Hi Dave do we know if this data they provided is from the period of the 1000 miles after fitting or since the car was built?
I suspect it must be from total miles from new as it seems highly unlikely for 4K engine starts to be completed in 1000 miles..
I would also assume that the 900 starts completed at standstill are stop/starts activated by the car to help it met the fuel economy/emission levels needed, and not the owners fault.

Like me I am sure many of our owners were never advised that this car was not designed for short journeys as that appears to be what the above is stating ? Does this mean we have been mis-sold ?
And again as pointed out so many times if the car was building up soot through short journeys why is the light not coming on requesting an active reg by the driver to convert the soot to ash ?

As they are indicating that it’s not getting up to temperature to convert the soot to ash…

Grabbing at straws comes to mind…never mind only a few more days and this March’s Porsche Post with the GPF article in it will be dropping on the desks of the decision makers at Porsche UK head office in Reading.
Let’s hope that galvanises some action from the Brand to put this ridiculous episode to bed once and for all.

I have owned my car for coming up to 1 year,covered around 2000 miles and it’s been of the road in an OPC for around 20 weeks of that period..

 

[911hillclimber]

Just a non tech thought.
When Porsche develop these cars do they not do through extensive test processes against Standards to be met but also to ensure real world conditions are trialed and tested and any issues sorted?

In todays traffic around the world such real testing is key to the vehicle meeting customer expectations. (imho)
Going to work is one such condition, slow short runs rather than mega Euro trips at 10/10's?
Few do the latter, many do the former.

When I worked in he car industry in the late 80's we made door locks and such hardware (Wilmot Breeden no less) and had to exceed Standards, but we also had real world testing, one was nick named 'Angry-with-the-Wife' ; 20 vicious as possible door slams that sometimes smashed the door glass.

Totally unscientific but real.
Do Porsche drive to Sainsbury's?

 

[Cyclemotor1958]

Hi Guys & Girls

Without prejudice

Hi

Enclose a video showing you the ups and downs of a differential pressure sensor.

Grab a coffee or tea and watch this video, it shows you how these things should work.
Remember that this sensor is responsible for telling you when your soot accumulation is at a point where the ECU instructs you to do a active regeneration reference the handbook instruction.

We know from all our data collected on our cars, this doesn’t seem to work.
It also should pickup the excessive pressure reading you would get if the filter was actually at 100%.

And bearing in mind, and I know Iam repeating myself many times here on this subject, we never see any soot values that would normally initiate a regeneration.

And finally if you believe the data on these GPF reports to be correct, you run the risk of incorrect diagnosis, and unnecessary expenses.

And sadly at the moment we seem to be doing that.

A simple back pressure test on the GPF would certainly rule out a very expensive exhaust.

Two more 718 owners have joined our quest this week with 9K quotes to fit new filters and their reasons for the failure is driving styles. Why are the dealers still insisting that these filters are faulty, they couldn't be more wrong.

Regards
Dave

 

[glenn duval]

Hi Dave I think it would be a good idea to have one of the faulty cars looked at by this guy.
looks professional, and very methodical in is approach.
I bet the dealers are not doing all these tests.

 

[Scrounger]

It’s pains me to right this but you MUST go to the motoring press. The only way that Porsche will sit up and listen is if you make it public and I don’t class PP as the public motoring press. By not doing so and waiting for Porsche UK and AG to come up with a solution you’re just prolonging the issue. It only takes 1 person to call a magazine and they’ll be all over it.

Dan

 

[Cyclemotor1958]

Hi Dan,

Without Prejudice

In the beginning I have always thought that as long as Porsche UK cover the cost of replacing these filters free of charge then we should have no need to go public.

Every case I have dealt with, they have eventually covered the cost, its not been easy, but with the GPF data information we have collected along the way its really helped.

We now know, and the dealers and Porsche know, that the original diagnosis on replacing these filters was incorrect, because the cars fitted with new filters are coming back with the same fault.

Currently we have several cars at the dealers that are having further investigations on the engines to look for possible oil contamination to support the high oil ash levels in the new filters. And from what I am hearing they are struggling to find a definitive fault, again positive news.

The only thing I would add to this is do not dismiss the AOS function on these cars, they need to be checked by the dealers more often.

To me its only a matter of time now after all this unnecessary work as been carried out, that Porsche will realise this is a software issue that needs immediate attention.

Its always been my intention to publish as much technical information has I could to help our owners and Porsche to get to a resolution quickly.

We now have the evidence to confirm that the incorrect oil used and the driving style excuses have no bearing on this problem.

And hopefully the dealers will stop embarrassing themselves by not even mentioning these excuses for the failures.

We need to protect the integrity of these vehicles, restore confidence in these cars, and fix these cars, because their is nothing out there that can equal the driving experience that these cars can give our owners.

I believe we are at a point now where after all the hard work that has been done, and the time spent, we could be closer to a resolution, we just need Porsche Technical to look at the software.

If you would like to be the person that contacts the motoring press then its up to you, I certainly will not be doing that.

Regards
David

 

[Cyclemotor1958]

Hi Glenn

Thanks for your post,

I sent off some information this morning to Jimmy, the chap in the video, to see if he would like to look at one of our cars.
Fingers crossed

Regards
Dave

 

[Paul-718gts]

Porsche Post Digital March 2025

issuu.com

For anyone who hasn’t received their printed copy here is a link to the digital version with the long awaited article on this GPF issue.. pages 74 to 76
Please share your thought’s..
We are still awaiting the stronger forum version and I believe a letter that was supposed to be sent from the club to Porsche HQ Reading..
Wouldn't it be great to get a formal quote/response back from these individuals that were due to receive their personal copy informing both the current and future owners what the conclusive root cause is and corrective action they are implementing to rectify

 

[BrianJ]

As a one-time engine designer (crikey, 50 years ago!) I think that is a very informative and well balanced article. It explains the challenges and the issues in an objective and unemotional way - hard to do when so much cost, obfuscation, work and emotion has been experienced by so many members and owners who have been involved. I sincerely hope that Porsche from both a technical and a marketing perspective give the Club and the owners appropriate recognition for the way that the article (and the work behind it) has been carried out and presented when it could easily have been much more public and confrontational. I think Porsche have been extremely slow to recognise and confront the issue. The comparison between the rapid and public response to eg 911 centre locks and the slow and painful 718 GPF gives the impression that Porsche think the 718 reputation isn't very important to them. Well done to all involved and I hope an appropriate and permanent technical and financial resolution is soon available for every owner.

 

[911hillclimber]

Good article imho in the Post, and not just squeeeezed into a small gap, but 3 pages.
In the front of the Post is the usual column of the Porsche UK rep who seems new and keen. I think he is on the marketing side but also Customer Satisfaction.

Maybe a good route to the (UK) Top Brass?

 

[JohnCRS]

There is still a lot going on behind the scenes (Thank you Dave!) Thanks to Richard Gotch for a well balanced piece which reads very well. It does not fully reflect the emotion and frustration that exists, for example on this forum, but it will hopefully open the door to a dialogue with the Porsche technical department and a discussion about the work Dave has been doing and the results. All along we have been tryng to find out what is actually going on with these GPF's and to avoid the situation where OPC's try to charge owners a great deal of money for what we believe is a mis-diagnosis. Someone must know.

Unfortunately the relationship between the club and Porsche GB is through the marketing department. We would like to talk to the techncal team. Fingers crossed that we will be able to do a follow up.