Cayman 718 GPF Failure

[Motorhead]

Hi David,

May I endorse Mark and Paul’s comments and once again thank you for your continued efforts in the hope that something can be done to those affected. Thanks also for the very useful update to keep us all informed about developments.

Undoubtedly there is a serious problem here, but the main difficulty appears to be getting Porsche GB to recognise it as such. The Club has close links with Porsche GB and I wonder if there’s anyone on the management team who could raise the issue with them? Someone with technical clout would be a great advantage.

Incidentally I’ve posted a link in the Tech section of the Cayman WhatsApp group referencing this forum post for anyone who’s had a 718 F-4T GPF failure but haven’t yet had any response, although that’s not to say no-one has had a look on here.

Jeff

 

[michaeldowgill]

Hello. This is my first post. I am on my 4th Cayman from 2013 and currently a 718 Style Edition June 2024 with 8500 miles.
My previous car was a 2019 Cayman T with the GPF. I never had any alarms to carry out a regeneration of the GPF or the final alarm in my 22,000 miles.
This problem is very concerning and thinking back to anything that was common on both my Cayman T and current Style Edition, both had a random two bleeps warning tone but no indication on the screen to show what the problem was. Could this have been the GPF first or second warning to regen!
Has anybody else had these 2 random warning bleeps with no indication on the screen.
Michael Dowgill

 

[Motorhead]

Hi Michael,

Welcome to the forum, and thanks for your input.

I don’t know whether or not your two bleeps are relevant in this case, but at least it’s another piece of potentially useful information. It seems that they weren’t accompanied by any warning message, so it could have been an unrelated issue, although it’s very odd that it happened on both cars. Did the bleeps occur when the engine was running?

I seem to recall that you get a double bleep if when locking the car you’ve left the front luggage compartment, rear hatch or glove compartment lid open, and it also happened on my 2009 987.2 CS when the alarm module failed.

Jeff

 

[michaeldowgill]

The two loud bleeps only occurred when the engine was running and in motion at different speeds. It says in the manual that some warning messages are preceded by additional acoustic signal sounds. I have taken this as it could be the GPF has become clogged with soot but not indicated in the instrument panel or display. So

 

[michaeldowgill]

The two loud bleeps only occurred when the engine was running and in motion at different speeds. It says in the manual that some warning messages are preceded by additional acoustic signal sounds. I have taken this as it could be the GPF has become clogged with soot but not indicated in the instrument panel or display. So

 

[michaeldowgill]

So I have been carrying out the procedure to clean the particle filter indicated in the manual when I get these acoustic signal sounds with nothing showing on the instrument display.

 

[medmick]

I saw this issue posted in the Porsche Post, and have had a good read. Not much point extending your warranty if this isn't covered. As the GPF is part of the Cat, surely this classes as a Cat failure?
Having blown the dust off and read the manual, these are my thoughts...
Could the stop/start also be causing an issue? (does this impact the temperature in the exhaust system , during normal driving?) When driving, on the flat 6, you can hear the cylinder deactivation, does this work the same on a flat 4?
Has anyone measured the GPFs before and after an "Italian Tune"? Or noticed a difference?

Great work btw

 

[Motorhead]

So I have been carrying out the procedure to clean the particle filter indicated in the manual when I get these acoustic signal sounds with nothing showing on the instrument display.

It would seem that definitely there’s a connection Michael, although your guess is as good as mine as to what the bleeps are meant to signify. Perhaps it’s just an indication that the procedure has been conducted successfully? Unfortunately you’ll never know unless the dealer hooks up the PIWIS diagnostics system for confirmation, and judging by what David has said a lot of the data produced appears at best to be suspect.

Jeff

 

[Motorhead]

I saw this issue posted in the Porsche Post, and have had a good read. Not much point extending your warranty if this isn't covered. As the GPF is part of the Cat, surely this classes as a Cat failure?
Having blown the dust off and read the manual, these are my thoughts...
Could the stop/start also be causing an issue? (does this impact the temperature in the exhaust system , during normal driving?) When driving, on the flat 6, you can hear the cylinder deactivation, does this work the same on a flat 4?
Has anyone measured the GPFs before and after an "Italian Tune"? Or noticed a difference?

Great work btw

It seems as though the insurer who underwrites the Porsche Extended Warranty erroneously considers the GPF in the same manner as other filters - like those for oil, air and cabin - which are classified as wear-and-tear items, and Porsche hasn’t seen fit to challenge this. This of course is ridiculous because, like the cat converter [which could also be considered a filter!], the GPF isn’t a service item and should last for many years without attention. The fact that the cat converter and GPF is a combined unit on the 718 F-4T makes the whole thing even more ridiculous and means that the replacement cost is necessarily very high.

It’s impossible to say if stop-start is a contributing factor to GPF failure, but surely sufficient development work was done to make it unlikely? You would have hoped that Porsche’s development procedures would have monitored soot and particle build-up in the GPF for a comprehensive range of driving conditions. Having said that, it’s clear that it wasn’t as thorough as it should have been judging by the number of premature GPF failures.

Unlike the 4.0L F-6 engine, I don’t believe that the F-4T engine uses cylinder deactivation.

Jeff

PS: I’ve previously made the point that if the device had been call a Gasoline Particulate Trap and not Filter, I wonder if the same situation would have arisen?

 

[michaeldowgill]

It would seem that definitely there’s a connection Michael, although your guess is as good as mine as to what the bleeps are meant to signify. Perhaps it’s just an indication that the procedure has been conducted successfully? Unfortunately you’ll never know unless the dealer hooks up the PIWIS diagnostics system for confirmation, and judging by what David has said a lot of the data produced appears at best to be suspect.

Jeff

Thanks for your reply Jeff. Next time I visit my dealer I'll get them to have a look at the data. I am working on the assumption that we have never had an important alarm not appearing on the instrument cluster before! It's certainly ridiculous that owners are being asked to pay £7,500 by Porsche.

 

[Motorhead]

Yes, it’s a totally unacceptable situation for those affected Michael. It appears that most GPF failures have occurred on the early cars - c2019 I understand - and hopefully your current 718 won’t be affected.

Let us know how you get on with your dealer. Any information will add to the knowledge database.

Jeff

 

[Paul-718gts]

Hi Everyone,
Would be interested if anyone has a genuine estimate for their GPF to be replaced they would be prepared to share with me.
I am currently going through the pain of dealing with a GPF that is reported to be 100% after the car being sold to me 6 months ago at nearly 78% full(no light present even though it’s in the window and less than 8% below level 5) less than 1400 miles later of weekend fun driving days out its full ?
Have been informed the full cost before any aid from Porsche GB and dealership is nearly £10k that still leaves a contribution from me of nearly £3k..
Have asked for a breakdown of costs as was advised it’s only about 5 hrs work 4 weeks ago… awaiting a face to face meeting with the Dealership principal next week.

Still awaiting a list of questions to be answered and from the dealership and it’s been 6 weeks with no car..

Thanks in advance

 

[Motorhead]

Hi Paul,

Sorry to hear that you’ve been affected by this issue, and I hope that it can be resolved to your satisfaction … eventually!

I must say that what you’ve quoted sounds like a ridiculous price. In post #4, Dan reckons that the unit costs £2,350, although I don’t where he got the figure, and 5hrs labour even at Porsche dealers’ extortionate prices [c£250/hr?] doesn’t add up to £10k even if the cat-GPF is twice that price.

BTW, can you direct me to the Driver’s Manual page describing the regeneration procedure? I don’t own a 718 myself but was talking to a chap in my village [also a PCGB Member] who has a 2019 718 GTS who wasn’t aware of the problem, and so I brought him up to date on the issue. He said that he’d have a look for it himself, but maybe you can direct him because sometimes these things are tricky to locate.

Jeff

 

[Scrounger]

Here you go Jeff. Price is from Euro Spare and is ex VAT! I would imagine they’ll also all new gaskets and clamps and other ‘sundries’.

Dan

 

[medmick]

BTW, can you direct me to the Driver’s Manual page describing the regeneration procedure? I don’t own a 718 myself but was talking to a chap in my village [also a PCGB Member] who has a 2019 718 GTS who wasn’t aware of the problem, and so I brought him up to date on the issue. He said that he’d have a look for it himself, but maybe you can direct him because sometimes these things are tricky to locate.

Jeff

Jeff, David posted this on post #110 (page 6). Its in the Dashboard alarms section of the handbook. Basically, turn off cruise control, put car in sport mode, dont change up til you get the up arrow (i would not change up until you are close to the rev limiter!) then lift off, repeat until alarm clears, but it looks like that no one has seen the alarm yet! SO this is prevention rather than cure....

 

[Scrounger]

Just to add to Mick’s post here is the extract from the manual in the My Porsche app

 

[Motorhead]

Many thanks chaps. I’ll pass on the info to Ray, assuming he hasn’t found it already.

Dan, is that an OEM part rather than a genuine Porsche part? If so that could account for some of the price difference since Mark quoted £7,500 for his replacement at a dealer, but Paul’s quote of about £10k is ridiculous.

Jeff

 

[Scrounger]

As far as I know they are genuine Porsche OEM parts with Porsche part numbers however I’ve just looked on Design911 and the same part number comes up with a price of £6564.92

 

[Motorhead]

Design911 always seem to be more expensive than the dealers Dan, and although you get some sort of discount, probably you’re better off with a dealer’s guaranteed 10% discount for Club Members.

The price you’ve given seems to be more in line with Mark’s £7.5k quote for the work, ridiculous though it is.

Jeff

 

[Cyclemotor1958]

Hi Guys

Without Prejudice

Regarding the GPF cost the latest quote I have seen was.
Labour £1,543.75
Cat Converter, (sorry GPF) part number P982 254 400AF £5,912.22
Nuts and bolts £59.24
Grand total £7,515.21 + vat

It's the Catalytic Converter that makes it expensive.
Bearing in mind the GPF part, doesn't have a separate part number, because it lives inside the Catalytic Converter.
So how can a part, with no part number be excluded from the extended Warranty.
Doesn’t sound right.

I Would like you all to see this GPF Val report, which shows you clearly all the information I gave on my last post.

1. The soot values always show a very low reading K211 & K221

2. Oil / Ash load measured at 100% this requires replacement by the dealer K231

Note. if you have had your GFF regenerated and you were it told it went to 0%, this was wrong.
Usually the reading above is quoted K230 oil / ash load calculated which is always at 0.00%

3. The temperature readings T255 and T251 always show the T251 temperature with a
ridiculously low reading, which doesn't make any sense.

4. Leaving the best till the last, K251 the differential Pressure sensor, the sensor that does all the work.
This usually shows a very low reading, which you would not expect with a GPF filter that is blocked with ash.

Or like this one showing no reading at all, I have seen lots of these set at at 0.00 hPa

We should look at these sensors, because they are not working, their function is to monitor the soot load in the GPF and its obvious they are failing.

When you fit a new pressure sensor the part number as changed slightly with the letter D on the end. And if you search on good non dealer parts sites, quoting the original number PAE906051, they say it was superseded around April 2024.

We need to be looking at this data on the Val reports, and double checking that the GPF is indeed blocked, before we replace it.

I am certain that this sensor is one of the issues on this exhaust system, after all these cars have run ok for the last 5 years, then all of a sudden they are failing.

Replacing the GPF may not be the answer, and they are showing signs of blocking again after a new GPF as been fitted.

The AOS is another concern, again this part number as been changed, the quickest route to send oil from the sump into the cylinders is through a faulty AOS

We should check the exhaust tail pipes on cars with suspected faulty GPF filters and look for heavy soot deposits.

You should have a slightly grey / brown colour inside the pipes.

Well that's enough for now, hopefully should have some news later in the week

Dave