Cayman 718 GPF Failure

[Cyclemotor1958]

Hi, its me again,

Without Prejudice

Following on from our discussions regarding the soot particulate warning light that is not working on the the cars we have been involved with.

Porsche Technical have always been sure that this warning light should come on if the GPF filter is clogged with soot.

Enclose a written response from Porsche Customer Care confirming this, on a vehicle that recently had a new GPF filter replaced free of charge.

This was due to a manufacturing defect confirmed by Porsche Technical, because the trouble code P242F was present.

On all the vehicles that had an oil / ash reading of 100%, Porsche Technical advised the dealers to replace the GPF.

I have managed to see the GPF exhaust data, which was suppled by our drivers,
and in all cases they had a very low differential pressure sensor reading.

In fact the highest reading out of 12 cars was 5.64 hPa.

Sorry for repeating myself again but when a filter is blocked, you would always get higher readings than this.

Bearing in mind the differential pressure sensor would normally signal the ECU to start the regeneration process, put on the warning light, and assist in heating the exhaust to burn off the soot.

So if these GPF filters are blocked with ash at such low mileages, why is this happening.

Could it be that incomplete regenerations by the vehicle without the engine management assisting, during low temperature driving is causing the premature ash build up.

This may explain the situation we are in, after all many studies have been carried out regarding ash behaviour in GPF filters. We know what the affect of using the wrong engine oil can do.
It's quite a complex issue, and it's ongoing.

And we must not forget the role the AOS can play in contaminating the GPF with excessive oil droplets.

Back to the light not coming on, a simple check would be to increase the pressure on the differential pressure sensor with a mityvac tool.

These sensors generally run between 0 and 100 kpa, at idle, which is 15 psi.

The mityvac tool has a max pressure of 30 psi, this range should be enough to put on a warning light, or a trigger a diagnostic trouble code.

The only issue that we have had recently on some of the vehicles that have had replacement GPF filters fitted, is
the dealers found it difficult to reset the oil ash % level back to zero.

So if we could get the dashboard soot warning light working.

Check for exhaust back pressure, to confirm that we need to replace the GPF.

Check the function of the differential pressure sensor and its affect on the upstream temperature reading T251.

Find a quicker way of re setting the oil / ash reading %.

Start checking the AOS vacuum readings on these cars with a manometer to stop oil contamination hitting the GPF.

Then hopefully things should be alot better.

Sorry for going on again

Dave

 

[Paul-718gts]

Club Representatives -
As Dave’s last paragraph suggests a statement from the club updating its members on the progress to date on this matter with Porsche GB is all I think it’s members are looking for at this point.
It’s been nearly 3 weeks since there was a mention of the committee engaging Porsche and it’s been radio silence since..

Club Representatives
Yet another post by David providing some more detail and a method to help the manufacture in its diagnostics … And still no updates or a communication from either the club of Porsche GB on this matter ???

 

[Wrightrubber]

How much more technical detail does Dave need to share for Porsche GB and the Club to listen and be proactive in dealing with this issue...it is not going to go away!! Porsche Technical are still insisting the filter light will come on to alert the driver a re-gen is needed and to drive it in a certain manner....why then when asked on numerous occasions can't they not show this light illuminated..........because it does not work!!

 

[JohnCRS]

I have been working with Dave throughout this period and can assure you that the club is trying its hardest to engage with Porsche. The Chairman has written directly and is pushing for a reply but, if Porsche wish to just deal with this, through their OPC's, on a case by case basis and not talk to the club about it, there is not a lot we can do. The overall numbers are small and, as has been stated before, if the issue had just been fixed under warranty we would all have moved on. As a club, our priority is to look after and support its members. Every case we have come across has received that support and has been, or is currently being, successfully dealt with.

As Dave has pointed out, we have a number of specific issues we are continuing to chase down:
The GPF is not blocked - wrong diagnosis
The Differential Pressure sensor can be faulty giving false readings
There should be a regeneration warning which comes on before it gets to a CEL. This system is inoperable.
Numerous examples of appalling service, mis-diagnosis and, potentially, overcharging
Claiming that the GPF is a service item when it is not referred to in any service schedule, check, or the handbook.
Producing (VAL) reports which clearly dont make sense.
Claiming that the car is fit for purpose whilst saying that there are types of driving that cause the GPF to get blocked
Being unable to conduct basic tests, such as AOS function, exhaust back pressure etc. which are cheap to do and would either corroborate or contradict readings.

Remember, we are dealing with Porsche OPC's here who can only evaluate what shows up on the car dashboard, PIWIS tester and diagnostic system, usually by changing out successive bits until the warning light stays out after the reset. But I feel sorry for the OPC's as they can only work as instructed by Porsche. However that does not excuse the way some OPC's seem to treat their customers.

We are trying hard to bring this to a conclusion.

John

 

[Paul-718gts]

I have been working with Dave throughout this period and can assure you that the club is trying its hardest to engage with Porsche. The Chairman has written directly and is pushing for a reply but, if Porsche wish to just deal with this, through their OPC's, on a case by case basis and not talk to the club about it, there is not a lot we can do. The overall numbers are small and, as has been stated before, if the issue had just been fixed under warranty we would all have moved on. As a club, our priority is to look after and support its members. Every case we have come across has received that support and has been, or is currently being, successfully dealt with.

As Dave has pointed out, we have a number of specific issues we are continuing to chase down:
The GPF is not blocked - wrong diagnosis
The Differential Pressure sensor can be faulty giving false readings
There should be a regeneration warning which comes on before it gets to a CEL. This system is inoperable.
Numerous examples of appalling service, mis-diagnosis and, potentially, overcharging
Claiming that the GPF is a service item when it is not referred to in any service schedule, check, or the handbook.
Producing (VAL) reports which clearly dont make sense.
Claiming that the car is fit for purpose whilst saying that there are types of driving that cause the GPF to get blocked
Being unable to conduct basic tests, such as AOS function, exhaust back pressure etc. which are cheap to do and would either corroborate or contradict readings.

Remember, we are dealing with Porsche OPC's here who can only evaluate what shows up on the car dashboard, PIWIS tester and diagnostic system, usually by changing out successive bits until the warning light stays out after the reset. But I feel sorry for the OPC's as they can only work as instructed by Porsche. However that does not excuse the way some OPC's seem to treat their customers.

We are trying hard to bring this to a conclusion.

John

Hi John,

Thank you for providing a response on behalf of the club.
Given the club is made up largely of Porsche owners I would like to think that the Board would gain some traction with Porsche UK on this matter which I believe is larger than the numbers we have recorded as I myself have interacted with at least 4 owners outside of the Porsche owners forum just through some basic Facebook forum searches..

If the board fail to gain interaction on resolving the issues you have mentioned with Porsche UK would the board be happy to support and advice the membership in taking other routes which could ultimately include or lead to legal action on items such as warranty cover and systems around the GPF being fit for purpose?

 

[Greenman986S]

Engine starts = 2148
Motor operations at standstill = 641

Am i reading that correctly as the car didnt go anywhere?
Or does it have stop / start?

 

[Oldbiddy]

Engine starts = 2148
Motor operations at standstill = 641

Am i reading that correctly as the car didnt go anywhere?
Or does it have stop / start?

Good spot. It has stop/start. Not sure that explains it though.

 

[Paul-718gts]

Hi

Just sharing this information in case it ,ight be useful to others. Note I am not identifying the OPC They have been very helpful over this issue..

Car is a 2.0L Cayman PDK MY21. Registered 4/8/20. Mileage = 22.8K.

PART 1

Whilst the car was in the workshop today for other work to be done, I took the opportunity to ask for an OPF soot/ash loading test. The results of the diagnostics were:

K211 – Particulate filter bank 1, soot load calculated = 0.39%

K221 – Particulate filter bank 1, soot load measured = 0.00%

K230 – Particulate filter, oil/ash load calculated = 0.00%

K231 – Particulate filter bank 1 – oil/ash measured = 61.57%

Diagnosis and commentary – Soot levels are low so regenerations have probably been occurring, but exhaust temperatures may still be insufficient so ash is generated. [Due to the problems noted elsewhere in this thread I have been regularly following the instructions concerning regeneration described in the manual as if the particular warning light had actually come on]. Particulate warning light has never come on. OPC confirms that this light does NOT come on. [Interpretation – The manual is incorrect for our region].

Car may require longer runs in order to heat exhaust to required temperatures. Diagnostics reports numbers of:

Engine starts = 2148

....Motor operations at standstill = 641
....Motor operations between 0-3 miles = 631
....Motor operations 3-6 miles = 215
....Motor operations over 6 miles = 658

Engine runs = 2146 (discrepancy of 2 compared to number of starts)

....Between 0-10 minutes = 1199
....Between 10-30 minutes = 590
....Over 30 minutes = 357

PART 2

Intended to try a “dynamic” regeneration but an out of workshop time. Cost = 1 hours labour. Will book this for next week and will report the results then.



Cheers Alan

Hi Alan,

Thank you for sharing your information and good to see the OPC was working with you in sharing this information.

Looking at you ash reading of 61.57% has the OPC suggested a forced regen is needed to reduce this % ?

Not sure this is possible as my understanding of the regen process is to turn soot into ash .. be interesting to see the results of part 2.

Regards

Paul

 

[Oldbiddy]

Hi Alan,

Thank you for sharing your information and good to see the OPC was working with you in sharing this information.

Looking at you ash reading of 61.57% has the OPC suggested a forced regen is needed to reduce this % ?

Not sure this is possible as my understanding of the regen process is to turn soot into ash .. be interesting to see the results of part 2.

Regards

Paul

That is my understanding too so I asked that specific question. They seem to think it is do-able, but the proof of the pudding.......

 

[Cyclemotor1958]

Hi Alan,
Thanks for the info, could you ring me on 07769 590119, would like to catchup with you
Dave

 

[Cyclemotor1958]

Hi Alan,

Without Prejudice

Your Dealer is right telling you that the particulate light doesn't come on.

This is what we have been saying for the last year, all the drivers that have had GPF issues have all confirmed they have never seen either a light or message on the dashboard.

The point is, it should come on.

Manufacturers have to apply for a certificate of conformity covering the emission controls, before they can sell their cars.

They have to give assurances that the emission control system fitted to these GPF cars would notify the driver that when the soot loading was high, a warning light would appear.

This driver instruction is written in the drivers handbook and clearly explains the regeneration method to be used.

This function enables the car to cope with short journeys, and deal with low ambient temperatures.

You dealer needs to speak to Porsche Technical, they have been telling us for the last 12 months that the light should come on.

Enclose information from Porsche Customer Care confirming this, sent to one of our drivers recently.

Just imagine what would happen if we switched off the soot loading warning lights on all the diesel cars currently on our roads tomorrow.

Afterall, both diesel DPF and petrol GPF cars have to deal with the soot, and turn it into ash.

After researching into the emission standards for 2019, its a big deal.

It details that if a manufacturer gets more than 25 complaints of the same emission issue with the same model car, it has to be reported by the manufacturer.

Do we all agree that this warning light not working is a major issue on a vehicle that is fitted with an emission device, designed to stop deadly particulates getting into our lungs.

Porsche engineer Martin Werner and his team worked on converting these cars for roughly 2 years.

Enclose part of an article that explains how these cars should work.

Maybe Martin could contact us on the Club forum, and put are minds to rest, 21 thousands views at the moment, we are not making this up.

Sorry for going on, but the cars we have been involved with, are not working as they should.

Dave

 

[Cyclemotor1958]

Morning Alan,

Without Prejudice

Further to your visit at your Porsche Dealer, and the information they gave you regarding your GPF information and your driving cycles.

Did they give you the upstream and in filter temperature calculated exhaust readings.

And did you ask for the driving cycle information.

The reason for asking this question is when Mark asked his dealer why his new GPF filter was running at 38% after 1300 miles, this was the dealers reply.

We have checked your driving journeys and the car spends to much time on tick over, and you are doing to many short journeys.

Mark challenged the Service manager, because his driving journeys included lots of motorway runs, she said that these cars are not suitable for half hour journeys.

So again, its your fault if the filter has to be replaced again, and you will be paying for its replacement this time.

It's a shame that this dealer had to check the Val page no 32 to find this information that supported Porsche and the dealers belief that it's the driver who is causing this filter to block up with Ash.

Enclose copy of this information for your attention.

Also regarding the dealer suggesting a regeneration because your Ash level is at 61.57 %.

Remember you can't burn ash twice, and if your light was working correctly you would not need to worry about Ash levels on such a low mileage vehicle.

When a differential pressure sensor records a high pressure reading it starts the regeneration process.

So if you put more pressure into the sensor using a mityvac tester, you would expect to see the warning light come on the dash.

The vehicle could be driven with this pressure tester attacheded to give it time to come on.

You could ask the dealer if they could do this for you, instead of spending time doing a regeneration on a car with very low soot readings.

Dave

 

[Cyclemotor1958]

Hi Everybody

Without Prejudice

Last week I had a chance to run a 718 Cayman GT4 on a dyno , and look closely at the GPF information it provided.

When looking at the information, it shows more aligned actual exhaust GPF temperatures, not calculated, as in the 2.0 and 2.5 vehicles.

To back this up, these cars have a exhaust temperature sensor fitted into each GPF.

Our cars don't have this sensor, could this be contributing to our problem.

After all the engine ECU needs a good accurate exhaust temperature to start a regeneration to burn this soot off and leave a small deposit of Ash in the filter.

I have always thought that if these cars do not carry out a good temperature regeneration, then that could lead to excessive ash deposits.

If I put damp wood in my wood burner and its not hot enough, I get lots of Ash.

All this is providing, these GPF filters are indeed blocked at 100%.

Enclose photo of the exhaust temperature sensor fitted to the GT4.

I will post out more information of the tunning company who invited me to check their car out in a future post.

These guys specialise in Porsche power upgrades.

Dave

 

[Scrounger]

Out of interest, on the 2.0 and 2.5 engines, do you notice a rise in oil temps when on a long journey and on the motorway?

 

[Wrightrubber]

Hi everyone,

Without Prejudice

I am still getting nowhere with Porsche GB in getting them to show me the light or warning message when a regeneration is required on my car. I sent them an e-mail requesting an appointment with their Technical Department and I would travel the 2 1/2 hour journey to Reading and pay for the diagnostic check and they could show me the light/message as detailed in the owners manual. I received a reply, which I have attached...... what a complete and utter joke, I thought Reading was their Flagship Centre!!! It would not be possible to meet with their Technical Department because 'they aren't customer facing'. They have referred me back to my local OPC and they have contradicted what Porsche GB Technical Department had previously told me should happen, with the light/message. I think it is absolutely obvious they know that it doesn't work and keep dodging the issue....well guess what I'm not going away!!

Mark

 

[Scrounger]

Many moons ago I had an issue with a previous car (MINI) and I wrote an email to AutoExpress. A couple of days after I wrote to them they gave me a call to ask some more questions. A week after that I was asked if a photographer could come and take a couple of photos for the magazine.

A week after the magazine was published I was contacted by BMW MINI UK asking if I would be willing to meet at a dealership of my choosing to have a discussion with the head of their engine development that was flying in to discuss the issue.

They asked me to leave my car for a few days while they ran some diagnostics and low and behold the issue was resolved.

Maybe it's time to take it to the press.

 

[Motorhead]

Not a bad idea Dan. Sometimes exposure to potential adverse press publicity is sufficient to overcome corporate stonewalling!

Jeff

 

[911hillclimber]

Indeed, a good idea from Dan.
As you are all getting nowhere with Porsche then time to work around that.

Porsche (and these models) get heaps of praise, maybe a tap on the Porsche shoulder will help them focus.
The Customer is forgotten about here, shameful behavior, and arrogance.

 

[Greenman986S]

Or maybe one of the Porsche magazines such as 911 & Porsche World, who have run several buyers guides on these models...with no mention of this issue

 

[glenn duval]

Funny how Porsche recall cars when they think a wheel might fall off.