Cayman 718 GPF Failure

[Paul-718gts]

Hi All
Backing up Dave's last post how can my situation make any sense, based on feedback from Porsche after my GPF is now apparently full and needs to be replaced ?

Car was purchased back in March and the presale VAL showed the following compared to the current VAL test after approx 1400 miles with no lights indicating that a regeneration was needed so I can only assume any soot build up was being managed by my driving style or the car.

K211 and K221 soot % reading between ) 0 % and 5.49% on both occasions
K231 Oil/Ash Load % reading 77.65% pre-sale and now 100% after 5 months and 1400 miles..

So in summary in 1400 miles the ash level has increased by 23% - there is no way in 1400 miles the ash level could be increased by burnt soot that has been trapped in so few miles ?

This can only leave wrong or excessive oil being burnt - well the car was fully serviced on purchasing we can only assume Porsche used the correct oil.. they have no way of checking if the incorrect oil was ever used pre my ownership..

This can only point at something allowing more oil through or the sensors not providing the correct readings.. or both ?

The mystery continues

 

[Scrounger]

Thanks for the info Dave and Paul. I seem to recall someone posted that one of the issues was the implementation of the GPF as a knee jerk reaction on the earlier cars without proper testing of the system. I can’t see Porsche throwing something on the car without proper testing however could it be the case?

Is there enough evidence to start a case in court with Porsche or at least send them a notification of intent?

Dan

 

[Motorhead]

I can recall the same Dan, although most likely it was just speculation, and you’d expect a company like Porsche not to release a car without sufficient development work being done and leaving early customers to be guinea pigs, but who knows … especially if the development team were under severe time restraints?

It seems to me that the whole issue depends primarily upon accurate determination of the ash load using data from the differential pressure sensor, and from what Dave is saying, if in most/all [?] cases it appears to be giving erroneous information then the simplest initial course of action would be to replace it and re-run the test before changing the GPF? However, getting Porsche to recognise the problem by looking critically at the obvious anomalies in the data - as highlighted by Dave - seems to be the biggest challenge. They appear to be in denial of the facts and persist in hiding behind the accusation that driving style is the cause of the problem.

Paul, correct me if I’m wrong but my impression is that the car was serviced by the Porsche dealer before your purchase, presumably with the correct low ash oil. In that case your 1,400 miles was driven solely with this oil, and still the ash level increased by 23%. Assuming you weren’t driving continuously like your gran, I agree that’s highly unlikely unless the AOS has failed or there’s a sensor error. Even if the incorrect oil was used at some time prior to your purchase, that’s irrelevant.

Have you challenged your dealer’s service manager to explain fully the suspicious results from the test? If he/she is unable to do this to your satisfaction I would ask with whom you can make contact at Porsche GB with sufficient technical competence to explain the results. If nothing else it would give Dave a shoe-in name for making his case!

The saga continues!

Jeff

 

[glenn duval]

Porsche throwing stuff on the car without proper testing.
Active gearbox mounts been a good example.

 

[Cyclemotor1958]

Hi Guys
If you type in Google.
Porsche is making a model range fit for coming emission standards.
You can read the whole article
Dave

 

[Scrounger]

So in short, they had 3 months to add a GPF!

Dan.

 

[911hillclimber]

This is quite a story and as just said, complex parts on these new models that seem to fail (engine mounts). I have an old 987.2 and had lots of issues. Just poor design and seems minimal testing before production starts.
As to costs:
Someone said labour is 4 hours, so at £100+ (?) about £500 to pay.
The part from Eurocarparts is £2800 + vat and special order, so I presume a Porsche part so about £3200

Thus, how can the £7500 cost quoted much earlier be justified?

Have I missed something (big) out?

 

[Motorhead]

Have a look at David’s post #220 for a detailed cost breakdown Graham, presumably based upon a Porsche dealer’s prices for replacing the GPF. Eyewatering!

Jeff

 

[Scrounger]

If out of warranty I’d be looking at an indie to replace.

Dan

 

[Paul-718gts]

Excellent work David, it would be great if Porsche technical would engage with us to explain what is going on here, this problem is not going away and i believe more and more cars are going to have this issue and Porsche's only answer is to change the GPF at a cost of £7500 with no explanation of the real cause and owners have no assurances that it won 't happen again. I honestly cannot believe an expensive component like this is not covered under the extended warranty, this most definitely is not a wear and tear part.
Appreciate the time and effort you have put into this David, the search for the truth continues.
Regards
Mark

Hi Mark,
Reading back through your original post for the 4th time it’s clear very clear to me that in regards to customer care and process of dealing with this issue I am on exactly the same journey as you had with the same time lines to events.
I still haven’t reached a resolution and I am coming up to 6 weeks from when the fault first occurred.
Would you be up for a call between us ?
Thanks Paul

 

[Wrightrubber]

Hi Paul

Absolutely, no problem. 07790135759.
Regards, Mark

 

[Paul-718gts]

Hi Paul

Absolutely, no problem. 07790135759.
Regards, Mark

Thanks Mark any times to avoid

 

[Wrightrubber]

Thanks Mark any times to avoid

Hi Paul, no, can call anytime.

 

[Wrightrubber]

This was the cost to replace GPF £5673.11 plus £532.21 Labour = £6205.32 plus VAT Total = £7446.38

 

[911hillclimber]

Wonder who the Eurocarparts source of supply is?

What a mess this all is unless you buy / lease new, sell / return within warrantee / conditions and have another or something else.

 

[Cyclemotor1958]

Hi everybody,

Without Prejudice,

Hope you had a good weekend.

Continuing on with my AOS checking campaign, its surprising that with all my dealings with Dealers last week regarding our GPF issues, they are still not using Manometers to check this parts function.

The only way you can check a vacuum controlled AOS is to use a manometer, we have been using these for years on 986,996 onwards in the independent Porsche workshops.

A few years ago, while working at my local independent Porsche workshop, I became involved with a really bad AOS failure on a Cayman 718 2018.

A friend of mine who runs another Porsche workshop, had this vehicle recovered in to him as a none runner.

After carrying out some diagnosis, they found engine oil was present in all the cylinders, preventing the car starting.

Having spent lots of years replacing faulty Air Oil separators before they totally failed, it seemed logical to check for a split diaphragm on this separator.

The AOS on this car had a removable diaphragm that you could buy separate, this was found to be split as suspected, the oil was drained from the cylinders, spark plugs replaced, lots of time spent.

The car started with lots and lots of white smoke, it took ages to clear the exhaust.

On road test they found that the car didn't go as well as it should have, so it was decided to transport the car to another Porsche independent workshop nearer the owners home.

The workshop found an issue with cylinders 3&4 on the camshaft adjuster mechanism.

They stripped the engine down and found that a small piece of the oil filter paper element had been sucked into the oil gallery that supplies the camshaft.

Photo below.

We could say that this is a very rare failure, and it may be, but I have seen lots of issues over in the states, reporting sudden failures of the AOS resulting in excessive white smoke emissions.

I have recently advised a chap in the states with the same problem, on the 718 forum, unfortunately lots of the forum members advised him, the white smoke is usually signs of a bad cylinder head gasket failure.
You can understand this, has the white smoke is really bad, when they fail, and very worrying.

You can purchase a monometer from Amazon for around £45.00, buy a Oil filler cap from the dealer for around £19.00, put them together, you are now in a position to test for a faulty AOS.
We measure the vacuum using the H20 inches of water setting on the manometer.

We have been checking some of these cars with my own manometers, and we have found readings as high of 46 inches of water, to a average of around 30 to 35 inches of water.
If we had the vacuum reading from a newly fitted AOS we would have something to go on.

986/996/987/997 gen1 AOS run between 4.0 to 6.0 inches of water
Gen 2 cars run between 14 to 16 inches of water.

The drivers of these cars that have either had the GPF fitted, or having one fitted , will have to fund the repair themselves

This part is covered under the Porsche extended warranty, but again the dealers are not checking the AOS for a possible fault, and then a possible claim.

This very important part is well under the radar at the moment.

We have on many occasions asked the dealers involved with our GPF faulty cars to check the AOS with a monometer, but unfortunately it seems they are not allowed to do this.

Bearing in mind that the quickest way to get engine oil and more soot deposits into a GPF filter, is to to ignore a failing AOS.

The dealer will charge them over £250.00 to carry out a diagnostic check on the AOS, looking for a trouble code for the AOS, that I believe doesn't exist, because it has no direct feed back to the engine ECU.

When the AOS starts to fail, it will cause the ECU to change the fuel trims, and it will have to compensate for the excessive vacuum and extra oil pollution.

This is not a good situation for a GPF emission device, that's trying its best to cope.
These GPF filters only hold around 1 to 2 grams of soot.

Enclose photos of the split diaphragm mentioned above.

Sorry to go on, but we need to get a grip of this quickly.

Dave

 

[Paul-718gts]

Hi Mark,
Reading back through your original post for the 4th time it’s clear very clear to me that in regards to customer care and process of dealing with this issue I am on exactly the same journey as you had with the same time lines to events.
I still haven’t reached a resolution and I am coming up to 6 weeks from when the fault first occurred.
Would you be up for a call between us ?
Thanks Paul

Do we actually know how much ash the GPFs fitted to our cars car actually hold ?
Other manufacturers and testing I have seen online say they are good for over 100k miles .. why are they filling up so quickly with ash or are they just not big enough ?
Or are they actually not full ?
The mystery continues ?

 

[Wrightrubber]

David very kindly sent me a Manometer to check the AOS/Vacuum on my car. This picture is the result, looks high to me but Porsche can't tell me what it should be!! I tried to post a video of the test but it wouldn't let me attach it.
Regards
Mark

 

[Cyclemotor1958]

Hi Guys and Girls,

Without Prejudice

Well, another driver of a Cayman 718 2019 car with a faulty GPF contacted me yesterday, with a low mileage car, that apparently needs a new GPF.

First question I always ask is, did the GPF warning light come on, and the answer I always get back was no, and this is the case with this car.

After all my dealings with these cars, the research carried out, and all the repeated questions asked, I think its time to finally put down this question to Porsche.

These cars that have failed, surely cannot be fit for purpose, the fact that all these drivers with these cars have not seen this warning light, bears this out.

If the warning light had worked on these cars, I would not be typing this sentence, so why on all the conversations with the dealers and Porsche has this question not been answered.

All GPF fitted cars were built with the assurance that they would comply with the new particulate emission regulations that are trying to deal with air pollution that sadly is killing people.

So if these GPF filters are faulty, and we are told they need to be replaced at a considerable cost, then surely they don't comply.

After carring out more research around GPF filter functions and laboratory testing of GPF, I found some interesting information as follows.

Regarding this article below, covering the use of radio frequency sensors to monitor soot and ash loading, it shows studies carried out to determine what ash was left after 160,000 km.

It showed that 0.14 to 0.25 milligrams of ash / kilometre was generated, and stored in these filters.

So 160,000 km is 99,400 miles x the largest value 0.25 milligrams =24850 which is 24.85 grams of ash.
If we knew the ash capacity of these filters we would then have a clearer picture of what's going on.

If we use this the data above on one of our cars with only 12,800 miles driven, the ash loading using the higher figure of 0.25 would only be only 3.2 grams.

This car requires a new GPF filter that's reached the 100 % oil / ash value, and its not been fitted yet, this doesn't sound right.

The second article covers work carried out by SAE international in 2021, regarding the use of the our sports exhaust valves with a GPF system.

It speaks about possible back pressure and the control functions required to maintain this emission system.
Could it be that when the exhaust is in its standard setting, back pressure is present, and causing issues with the differential pressure sensor, which we know is currently causing us issues.
It would also explain that when we read the Val reports on these affected cars, some of the data doesn't make any sense.

Also the instruction in the drivers manual to carry out a driver regeneration, tells you to put the car in sport mode, which should eliminate any back pressure if present.

Again if we use an exhaust back press gauge on one of these faulty cars we could either confirm this, or rule it out.

We have at the moment several cars that required a new GPF fitting, out on the road with the EML light off, and with oil / ash values at around 80% and 65%.

We achieved this by concentrating on the drivers hand book information, initiating the driver regeneration instructions, and we are monitoring these cars weekly.

One driver is using a diagnostic tester to check all we see on a Val report, that tester only costs a £100.00.

Its a shame that the GPF warning light isn't helping us.

Enclose the articles mentioned
Regards
Dave

 

[Motorhead]

Hi Dave,

Thanks for the interesting references. I assume that the 718 doesn’t have an RF sensor, and relies exclusively on the differential pressure sensor to monitor component build-up?

Keep up the good work!

Jeff