Fitment of Gasoline Particulate Filter (GPF) to Fabia Mark III

[Yotbuds]

Hi, I'm due to pick up a 2019 Fabia Estate 1.0 MPI SE tomorrow and have just found out that VAG have started fitting GPF's to petrol engine cars. I'm not sure if this applies to my model which is normally aspirated or is it just turbo engines? Thanks in anticipation.

[GeneralPurpose]

It isn't just VAG group fitting GPF's. It's all manufacturers. This is to comply with new emission laws. They are a combined unit with the CAT. They do not cause any problems whatsoever and work extremely well. They are not new and have been fitted to some cars and trucks for many years. Claims by some on here that the world would end when they were fitted en-mass are simply untrue.

 

PS. I'm ex-tech and an ex-engine design and development engineer. This was my field of expertise.

[Breezy_Pete]

Likely to cause problems on cars that burn lots of oil, which isn't unknown amongst VW group offerings. Even with low ash oils, the stuff's going to accumulate irreversibly in there, no?

 

[GeneralPurpose]

Hi Wino, funnily enough we didn't find any problems with GPF's on engines that burned oil. And, it's the same for CATS. Because CATS and GPF's are mounted so close to the cylinder head exhaust manifold, or if there is no exhaust manifold as on my car, and just the exhaust outlets from the cylinder head, burning a bit of oil makes no difference. Both the CAT and the GPF burn at incredibly high temperatures and are combined units in most cases, so it's difficult for ash in any quantity to form in petrol engine GPF units even if they burn a bit of oil. They certainly are not affected by any car burning 1litre of oil in 1000 miles or even much higher amounts. The gas pressure too is intense within these combined units which along with the high incineration temps keeps the GPF and the CAT pretty much completely clear, reducing particulate matter to a fraction of its original size. In fact we never found any noteworthy amount of ash in any GPF/CAT combined unit that had covered 100,000 miles or more. Clearly, if a particular car is burning larger amounts of oil than the figure I mention above then it may affect it sooner. The message is, GPF's don't cause any issues. just like CAT's really. When was the last time you replaced a CAT due to large ash formation? 

Edited 25 October, 2019 by GeneralPurpose

[Ootohere]

@GeneralPurpose

Who is the we?

 

Worth a read of the post by @silver1011 on Monday.

http://briskoda.net/forums/topic/456700-has-my-car-got-a-gpf

 

Edited 25 October, 2019 by Roottootemoot

[GeneralPurpose]

Hi George, the 'we' is me and the firm I worked for in my last few months before retiring. 

 

GPF's are quite honestly very reliable. I've never yet seen or heard of anyone with a problematic GPF and although they are now being fitted universally to nearly all modern cars, including many port injected engines, they are not new. Of course this doesn't mean someone could not get an issue, but you'd have to use the car for very short trips over and over and over again without the engine ever warming up, ever, before you get a problem. By then you'd have other issues with plugs fouling, too much fuel and water in the oil etc etc. So VAG is covering itself by giving the right advice to anyone that gets a clogging issue. But you'd also need to look at how you are using your car too and maybe consider a push bike with a basket instead. 😀

[Ootohere]

OK, so we have seen this before, 

could you just say how many 2018/19 100,000 mile plus VW Group TSI's GPF's you were looking at?

 

Drivers / Owners might never have an issue, but if they do have and ask at a Garage / Dealership it is good if the Sales Staff, Service Staff and especially the Workshop Staff and Professionals know what the procedures are that are in a Owners Manual and hopefully part of the Technicians training and knowledge.

 

No point just saying there is nothing to worry about GPF's will have not issues or warning likes show if there is one on the car showing and the driver can not find the section in the owners manual.

Edited 25 October, 2019 by Roottootemoot

[punyXpress]

Similarly, do these extended mileage tests include driving 5 miles, letting engine cool for 6 hours, repeat ad infinitum. Or is it drive for several months only stopping for refuelling and driver changes.

In the early 60s, there was a heroic Mini, not the most reliable of motors which was based on Teesside and its life consisted of being mercilessly thrashed by HGV drivers who reached their hours limit and wanted to get home a.s.a.p.

[Ootohere]

@punyXpress

& The Hillman Imp, a trully innovitive car in design and materials.

I remember before i ever got one being told they drove it non stop across Continents & around the world, and i knew of their motorsport success.

So they were tested fully in Heat, Cold, Humidity etc. 

  They should have tested as you say above in your post.  

Around Linwood & In and out of Glasgow as drivers would need it to get to and from work.

http://en.wikipedia.org/wiki/Hillman_Imp

 

All will be well and nearly all will have no issues, and if they have tough because there were supposed to be none.

Some will say you should have used public transport, walked or cycled to save the earth. Or buy / lease an EV.

Time will tell as far as it goes with GPF's VW went with.

http://hypermiler.co.uk/emissions/the-gasoline-particulate-filter-faq

 

 

Edited 26 October, 2019 by Roottootemoot

[Breezy_Pete]

@GeneralPurpose cats and GPFS are very different beasts. Cats have open passageways. GPFs, like DPFs have closed ones that force the gases (and entrained solids) throuh the substrate structure. Oil ash must accumulate therein because it does not burn.

 

 

I have no problem with GPFS as a concept, they really only have to deal with cold-start soot unlike diesels and their DPFs, but to claim immunity from ash accumulation from oil burning seems 'beyond science' let's say. Link me to peer-reviewed published material that demonstrates my lack of understanding and I will gladly learn from it.

[silver1011]

I remember being told by industry experts that DPF's were going to be extremely reliable and that it was highly unlikely the driver would ever know they were there.

 

Then all of a sudden they weren't, and we did.

 

Sure, DPF's and their catalysts have improved but it has taken a long time, and it has been the end user that has suffered and paid the price for their ongoing development.

 

DPF's had been around a long time too, before they made it into main stream car manufacture, so the fact GPF's aren't new offers me little reassurance.

 

Remember, it doesn't matter how much testing the manufacturers do, we're their guinea pigs,  and any early adopters i.e. those of us buying cars now, will be the ones that ultimately determine how reliable GPF's will be.

 

VAG fitted their first GPF to a mainstream model only last year.

 

Edited 26 October, 2019 by silver1011

[GeneralPurpose]

11 hours ago, punyXpress said:

Similarly, do these extended mileage tests include driving 5 miles, letting engine cool for 6 hours, repeat ad infinitum. Or is it drive for several months only stopping for refuelling and driver changes.

In the early 60s, there was a heroic Mini, not the most reliable of motors which was based on Teesside and its life consisted of being mercilessly thrashed by HGV drivers who reached their hours limit and wanted to get home a.s.a.p.

 

puny, yes indeed they do.

[GeneralPurpose]

2 hours ago, Wino said:

@GeneralPurpose cats and GPFS are very different beasts. Cats have open passageways. GPFs, like DPFs have closed ones that force the gases (and entrained solids) throuh the substrate structure. Oil ash must accumulate therein because it does not burn.

 

 

I have no problem with GPFS as a concept, they really only have to deal with cold-start soot unlike diesels and their DPFs, but to claim immunity from ash accumulation from oil burning seems 'beyond science' let's say. Link me to peer-reviewed published material that demonstrates my lack of understanding and I will gladly learn from it.

 

Wino, I've worked with teams who design these things and I've tested them over the years. I tested the first GPF's way back in the early noughties. These were for specialist engines. Surprisingly, GPF's haven't changed too much regarding their innards, but the thing that has changed is the engines they put them on and the oils and fuels that burn through them. Also they are monitored with better electronics.

 

Firstly, the fuels we burn are better, cleaner and make less pollution so that's a help to the GPF. Secondly, engines themselves run cleaner with massively less pollutants than ever. Thirdly, modern oils used in engines produce much less ash when burned, if indeed an engine is using some oil.

 

Don't forget that the idea of the GPF is to incinerate the particulate matter to almost nothing at a very very high temperature. So high in fact that the particulates are vaporised to a gas, not ash. Inevitably, some tiny amount of matter will remain as ash but the quantity of ash per volume of matter incinerated is very very low. Very little remains in the GPF per 1000 miles covered by an average driver. In fact, when we split them open to observe how much matter was present, often it was not easy to see anything at all. But if someone is driving a car with a thirst for oil then obviously there will be more matter present. We tested many engine types but found no issues with ash content because in essence there was no or very little matter present inside a GPF even after very high mileages. So they work fine in normal service. They are not as touchy as DPF's and don't have to deal with anywhere near the amount of debris that comes from even modern diesel engines.

 

In addition the GPF's have a tolerance built in to ensure that properly running and serviced engines will not cause the GPF any issues, even if an amount of oil is burned. However, if the engine is using excessive amounts of oil it will impact on both the CAT and the GPF eventually.  This is what anyone would expect. The average GPF will last the life of the car, just like a CAT will.

[Breezy_Pete]

So you are now agreeing that oil ash will accumulate in there. No need for quite so many words really.

[Dannyboy85]

38 minutes ago, Wino said:

So you are now agreeing that oil ash will accumulate in there. No need for quite so many words really.

So after all that and actual facts what are you arguing exactly? Do you have facts or just speculation? Because you seem to be arguing a point you have no experience with aside from what you “think”? 

[Breezy_Pete]

Is thinking hard for you?

[GeneralPurpose]

I've never disagreed Wino if you re-read my posts above. On the subject of so many words, just trying to give reassurance and understanding which many on here don't seem to have.

 

it's clear many folks are making a link between DPF's and GPF's. That's understandable. But folks need to be clear that the life of a DPF is vastly different to that of a GPF. A DPF has to stop particulate matter produced by an engine that burns entirely a dirty fuel oil product. This makes a lot of soot and other particulate matter all the time the engine is running, and that's made worse by the fact diesel engines have a considerably higher compression ratio than a petrol engine (producing more particulates) with the exhaust gases running very much cooler at the DPF unless reheated. All this means even more particulates will have to be trapped by the DPF. Therefore a DPF has a considerably bigger job to do on a diesel engine which results in very much more ash than a GPF has to deal with on a petrol engine.

 

There is no comparison between the volumes of matter a petrol engine produces and that of a diesel engine.

[Breezy_Pete]

But there may well be a comparison between the amounts of oil burnt in each context, and that is the main source of the ash. Hence my point; it is not magically going to be able to remove this ash.

[GeneralPurpose]

3 hours ago, Wino said:

But there may well be a comparison between the amounts of oil burnt in each context, and that is the main source of the ash. Hence my point; it is not magically going to be able to remove this ash.

 

Not quite sure where you are going or what you are trying to say. I've already explained there isn't a direct comparison between what a GPF and DPF have to cope with. A GPF isn't going to collect massive amounts of ash even if the engine burns just a bit of oil as most engines actually do. Most particulate matter is vaporised to a gas and leaves no ash. They are designed to cope with the amounts of oil use that manufacturers say is ok for their engines to burn. For most it's up to 1litre of oil per 1000 miles (quite a high oil burn rate), some allow more oil use. The GPF's cope ok with that and it won't affect their normal lifespan. Remember, not all ash is kept in the GPF or a DPF. Ash gets expelled during regens and in the case of a GPF the same happens. You can do the GPF clearance exercise to remove ash if you want at anytime. It doesn't rely on a regen cycle like a DPF does. But so far over the years of dealing with GPF's, I've never ever seen one with any real amount of ash in it. Some of our test cars had covered over 90,000 miles with a GPF fitted and been driven for over 2.5 yrs in every sort of environment and put to every type of use in every type of traffic. I've worked on vehicles of many types with GPF's for over 12 years and none of them had any issues. Under normal use a GPF will last the life of the car like your CAT does.

 

If a diesel engine is burning a lot of oil it will make a lot of ash and both it's CAT and DPF will eventually be affected. It will obviously follow that it will be the same for a GPF if the engine is burning a lot of oil. BUT, with a GPF, you'd have to burn a huge amount of oil to get issues and in that case you are far more likely to be worried about buying another car that isn't clapped out than the GPF.

Edited 26 October, 2019 by GeneralPurpose

[Breezy_Pete]

Ash doesn't get removed by regens though, it's not burnable. It's ash, it's what progressively fills up DPFs longterm and necessitates expensive replacement or off-vehicle cleaning. I cannot see why It will not do the same in GPFs.

[GeneralPurpose]

GPF's and DPF's both emit small amounts of ash during use, but GPF's are very different and are capable of emitting much more ash should anyone ever be unfortunate enough (unlikely) to get a clog. GPF'S generally don't get all sticky inside under normal use. If you notice the VAG instructions for removing the clogged particulate matter is to use high revs and then come off the gas for long periods, just letting the vehicle slow under it's own steam. This creates a vacuum in the GPF sucking matter up away for the honeycomb and making it airborne. Pressing the accelerater again and rapidly increasing revs expels the dirt and any burnt up ash. It can remove quite large amounts Normal driving will do this to some extend too. 

[Breezy_Pete]

You seem to be confused about what is soot and what is ash.

 

I'll not reply any more.

Edited 26 October, 2019 by Wino

[Dannyboy85]

I’d just leave it General we appreciate your contributions to the thread. Nothing you say is going to matter he’s made his mind up. Haha 

[GeneralPurpose]

Thanks Danny. 

 

Wino, no confusion here. But sorry I haven't explained it well enough for you to understand. 

[bigjohn]

With particulate filters I thought what remained after a regen was a small amount of ash which eventually fills the filter up - hopefully after many 100'000's of miles unless the wrong oil etc has been used. I don't think the ash is expelled - when full a new filter is required. An OPF/GPF/PPF replacement should be much cheaper than a DPF and with petrol all regens should be passive (hotter combustion).

 

That was my understanding anyway - to be honest I'll wait a while until the technology settles as many early implementations of DPF's weren't great (inc Octavia VRS pd!)

 

However I don't think OPF/GPF/PPF YET fitted to the Original poster's MPI (not direct injection) engine 

Edited 26 October, 2019 by bigjohn