V12 Misfire & Cat ingestion

[Caslad]

Felonious said:

AdamV12V said:

Quicksilver also make a replacement new manifold set, but it does come with sport secondaries, but if you replace the headers then you need a solution for where to place and connect the knock sensors, although if you do the BR chop job then that's not an issue. AM dealers will fit the QS solution with a little nudging I found, but to be clear neither solution is AM approved. However if your car is well past the point of any goodwill or warranty then thats not an issue either.

Anyway come the time that my primaries fail (hopefully never) then the QS header would be my choice over a chop job.

https://quicksilverexhausts.store/collections/asto...

Keep in mind that the sound will be different on all these. I compared mine side-by-side with someone with the Performance Pack 2 (new inlet manifolds, same primaries, sports secondaries and titanium pipes). The Aston option was a deeper sound. Velocity AP is very shrill (https://www.youtube.com/watch?v=5xBarRft-fk), which I personally don't like at all. So always try to hear what you're buying before you buy it as results will vary. Also, the back box apparently varied through the life of the car, so there's another variable to factor in.

I had the Quicksilver manifolds & race cats on my DBS, partly on the basis as AdamV12V alludes that AM
tacitly approve the Quicksilver system.
However I changed it for a BR system because whilst it sounded fabulous with pops & bangs on the overrun (the fitter described it as sounding like an LMP1 car) I felt it a bit too aggressive for the GT nature of the DBS and more suitable for the sportier V12 Vantage.
At some point I’ll get around to putting the Quicksilver system on ebay.

[karatemaserati]

Which years is cat failure and ingestion prone too? Spoke to an aston tech last week at a dealer ship and he said not too worry about it on mine as it only happens on the cars with increased valve overlap due to upgraded VVTI so post 2013...
He said if the cats go on earlier models they just get blown backwards

[VanquishRider]

Couple of points form me:

The CAT ingestion issue is very rare. But not unheard of. I'd like to see more data, such as miles, history, repairs, usage frequency etc.

A certain Indie pushes the fear of this and many other "issues" as their preferred sales method. They obviously sell a solution to every issue they make a video about.

Everyone jumps to the conclusion that coils and plugs must be responsible for misfires, but never carry out testing to prove this. The Vanquish group did carry out the necessary testing. All coils and plugs passed the testing. Much easier to test the coils than plugs though. What was found was that the PCV systems are often in a poor state and starting to breath heavier, this is causing the misfires. PCV Valves are sticking and the hoses are deteriorating and failing. You can find oil in the intake header rubbers, if so you have this problem. Dealers swap out coils and plugs, it's a fix, but not a cure and so the problem returns.

Misfires return, the CATS get fuel flooded, they burn and break up.

Interesting that it is being linked to later engines that may have increased valve overlap. Again, we need more data to see if that is true. Only met one guy who had this happen and the AM dealer tried to back out of the warranty as the car had the secondary CATS removed. Their problem was that they sold that upgrade as part of the original sale. So they ended up footing the bill and not AML warranty.

[anonymous-user]

VanquishRider said:

Couple of points form me:

The CAT ingestion issue is very rare. But not unheard of. I'd like to see more data, such as miles, history, repairs, usage frequency etc.

A certain Indie pushes the fear of this and many other "issues" as their preferred sales method. They obviously sell a solution to every issue they make a video about.

Everyone jumps to the conclusion that coils and plugs must be responsible for misfires, but never carry out testing to prove this. The Vanquish group did carry out the necessary testing. All coils and plugs passed the testing. Much easier to test the coils than plugs though. What was found was that the PCV systems are often in a poor state and starting to breath heavier, this is causing the misfires. PCV Valves are sticking and the hoses are deteriorating and failing. You can find oil in the intake header rubbers, if so you have this problem. Dealers swap out coils and plugs, it's a fix, but not a cure and so the problem returns.

Misfires return, the CATS get fuel flooded, they burn and break up.

Interesting that it is being linked to later engines that may have increased valve overlap. Again, we need more data to see if that is true. Only met one guy who had this happen and the AM dealer tried to back out of the warranty as the car had the secondary CATS removed. Their problem was that they sold that upgrade as part of the original sale. So they ended up footing the bill and not AML warranty.

Interesting. What’s the “Vanquish group”?

I was browsing Vanquish classifieds on AT this week and noticed one for sale with a new engine (under warranty at 15k miles. Do Vanquishes have a separate engine weakness, or is it a case of a different cause of the same ultimate problem?

[CSK1]

I can’t see how the cat ingestion could be linked to removing the secondary cats as I had the Performance Pack fitted to my V12VSR, which comes from the factory and is installed by the approved AML dealer and this involves removing the secondary cats which are replaced by a full titanium exhaust line but keeps the primary cats (which allegedly could potentially damage the engine.
I have spoken to my dealer about this and he says they have never ever encountered this problem.
So it could potentially and theoretically happen but it is not a common problem with these engines.

[VanquishRider]

CSK1 said:

I can’t see how the cat ingestion could be linked to removing the secondary cats as I had the Performance Pack fitted to my V12VSR, which comes from the factory and is installed by the approved AML dealer and this involves removing the secondary cats which are replaced by a full titanium exhaust line but keeps the primary cats (which allegedly could potentially damage the engine.
I have spoken to my dealer about this and he says they have never ever encountered this problem.
So it could potentially and theoretically happen but it is not a common problem with these engines.

I'm not saying it is or was. Merely reciting the story I was told by that owner. But Warranty would kick off if the car was modified. So you can see why they walked away from the warranty.

[VanquishRider]

CSK1 said:

I can’t see how the cat ingestion could be linked to removing the secondary cats as I had the Performance Pack fitted to my V12VSR, which comes from the factory and is installed by the approved AML dealer and this involves removing the secondary cats which are replaced by a full titanium exhaust line but keeps the primary cats (which allegedly could potentially damage the engine.
I have spoken to my dealer about this and he says they have never ever encountered this problem.
So it could potentially and theoretically happen but it is not a common problem with these engines.

Early Vanquish headers are a bit unique and not exactly a great design. But it is what gives the Vanquish its most unique and very preferable sound. They are not headers and flow 3into1. Never heard of a single one having the issue and I reckon I personally know at least 15% of all the UK Mk1 Vanquish drivers/owners.

The Vanquish group is a where these owners have pooled together to solve issues, create new and better parts and advise buyers. We also have some great days out.

Reliability is much higher than claimed by those who never owned one. Cost of ownership is also much lower than claimed by those who never owned one.

[Felonious]

VanquishRider said:

Interesting that it is being linked to later engines that may have increased valve overlap. Again, we need more data to see if that is true. Only met one guy who had this happen and the AM dealer tried to back out of the warranty as the car had the secondary CATS removed. Their problem was that they sold that upgrade as part of the original sale. So they ended up footing the bill and not AML warranty.

Interesting points, thanks for sharing. One thing to note is, as I understand it, the same headers were used on early 450hp V12 engineers as on much later 600hp+ engines, with higher temperatures and gas flow rates. The headers are having to work a lot harder with later engines than early ones, so maybe there are a few topics which might lead to later cars being more vulnerable.

What I know for sure is that the dealer I was at last week had two cars in - a V12VS and a DB9 - with spectacularly failed cats that had taken the engines with them. Regardless of the cause, the cats can and do fail.

[Jon39]

VanquishRider said:

Interesting that it is being linked to later engines, that may have increased valve overlap.

Perhaps this might be a logical reason.

Increased emissions regulations, perhaps meant the 'sucking back' (the regurgitating system) was greater on the later engines.

[cayman-black]

karatemaserati said:

Which years is cat failure and ingestion prone too? Spoke to an aston tech last week at a dealer ship and he said not too worry about it on mine as it only happens on the cars with increased valve overlap due to upgraded VVTI so post 2013...
He said if the cats go on earlier models they just get blown backwards

This doesn't sound right as we have heard about this issue on cars older than 2013.

[alscar]

VanquishRider said:

Couple of points form me:

The CAT ingestion issue is very rare. But not unheard of. I'd like to see more data, such as miles, history, repairs, usage frequency etc.

Interesting that it is being linked to later engines that may have increased valve overlap. Again, we need more data to see if that is true. Only met one guy who had this happen and the AM dealer tried to back out of the warranty as the car had the secondary CATS removed. Their problem was that they sold that upgrade as part of the original sale. So they ended up footing the bill and not AML warranty.

AM Works removed the secondaries and replaced with QS pipes on my V12S from new and were happy to put in writing that any issues ( there weren't any) would be covered by the warranty.

[Caslad]

From my understanding cat degradation & subsequent ingestion is a potential issue for all the Gaydon era V12s and is age rather than model specific.

Because the damage to the catalyst seems to arise from unburnt fuel detonating on the surface as a result of misfires whatever increases the risk of misfires increases the risk of catalyst damage. New cars with new coils, plugs & wiring are thus less at risk than older cars.

[AdamV12V]

So what we heave learnt from this thread so far is:

It is very rare
It is quite common
It only happens on newer cars
It is most likely to happen on older cars
It is caused when the engine not warmed up properly
It is caused by the engines which run hotter
Misfires are usually caused by failed coils or plugs
Misfires are not related to failed coils or plugs
Removing the secondary cats increases the risk
It has nothing to do with the removal of secondary cats
Reconditioned engines are not available
Reconditioned engines are available

So i think thats fairly conclusive then and now that we have reached a consensus perhaps we can move on?

Edited by AdamV12V on Tuesday 30th May 10:12

[Hoofy]

AdamV12V said:

So what we heave learnt from this thread so far is:

It is very rare
It is quite common
It only happens on newer cars
It is most likely to happen on older cars
It is caused when the engine not warmed up properly
It is caused by the engines which run hotter
Misfires are usually caused by failed coils or plugs
Misfires are not related to failed coils or plugs
Removing the secondary cats increases the risk
It has nothing to do with the removal of secondary cats
Reconditioned engines are not available
Reconditioned engines are available

So i think thats fairly conclusive then and now that we have reached a consensus perhaps we can move on?

So the conclusion is to buy an early Gallardo... oh wait.

Can you get newer sports cats? That might be a solution as that's a recommended mod for the early Gallardos to avoid the cat sucking issue.

Edited by Hoofy on Tuesday 30th May 10:17

[Jon39]

AdamV12V said:

So what we heave learnt from this thread so far is:

It is very rare
It is quite common
It only happens on newer cars
It is most likely to happen on older cars
It is caused when the engine not warmed up properly
It is caused by the engines which run hotter
Misfires are usually caused by failed coils or plugs
Misfires are not related to failed coils or plugs
Removing the secondary cats increases the risk
It has nothing to do with the removal of secondary cats
Reconditioned engines are not available
Reconditioned engines are available

So i think that's fairly conclusive then and now that we have reached a consensus perhaps we can move on.

We are experts in uninformed discussion and guesswork, Adam.
It provides entertainment, therapy and sometimes amusement, but often it does eventually seem to encourage a real engineering or electronics expert to step forward, who then explains the proper answer.

When an electronics solution is described, with wiring diagrams and CANBUS explanations, it is beyond my understandung, but it is wonderful that there are people who know how such magic works.
Ohms law and a battery with bulbs wired in series or parallel, is about my limit.


A recent example - Some people have said that hydrogen is the solution, to replacing the harmful emissions created by gas for domestic heating.

A graduate of combustion engineering has now explained, that because hydrogen has only approximately one third of the heating value of natural gas, the entire gas grid will be vastly under capacity, if the country moves to a hydrogen-based system.
Any such move will call for massive investment in pipeline infrastructure. The assertion that only the generation of hydrogen will be new expenditure, is a denial of chemistry.

[phumy]

Jon39 said:

We are experts in uninformed discussion and guesswork, Adam.
It provides entertainment, therapy and sometimes amusement, but often it does eventually seem to encourage a real engineering or electronics expert to step forward, who then explains the proper answer.

When an electronics solution is described, with wiring diagrams and CANBUS explanations, it is beyond my understandung, but it is wonderful that there are people who know how such magic works.
Ohms law and a battery with bulbs wired in series or parallel, is about my limit.


A recent example - Some people have said that hydrogen is the solution, to replacing the harmful emissions created by gas for domestic heating.

A graduate of combustion engineering has now explained, that because hydrogen has only approximately one third of the heating value of natural gas, the entire gas grid will be vastly under capacity, if the country moves to a hydrogen-based system.
Any such move will call for massive investment in pipeline infrastructure. The assertion that only the generation of hydrogen will be new expenditure, is a denial of chemistry.

Think you might want to check your graduates source.

[Felonious]

AdamV12V said:

So what we heave learnt from this thread so far is:

It is very rare
It is quite common
It only happens on newer cars
It is most likely to happen on older cars
It is caused when the engine not warmed up properly
It is caused by the engines which run hotter
Misfires are usually caused by failed coils or plugs
Misfires are not related to failed coils or plugs
Removing the secondary cats increases the risk
It has nothing to do with the removal of secondary cats
Reconditioned engines are not available
Reconditioned engines are available

So i think thats fairly conclusive then and now that we have reached a consensus perhaps we can move on?

Edited by AdamV12V on Tuesday 30th May 10:12

An excellent summary. I'd just add that, so far I can reasonably conclude, removal of primary manifolds and relocation of same to an outbuilding is expected to reduce the risk of primary cat ingestion (other than by a mouse) to almost zero.

And let's face it, a mouse eating a cat is pretty bloody rare.

[Calinours]

Jon39 said:

A graduate of combustion engineering has now explained, that because hydrogen has only approximately one third of the heating value of natural gas.

Sorry to add to the confusion, but it’s the other way around Jon..

Hydrogen 120-142 MJ/kg
Petrol 44-46 MJ/kg
Diesel 42-46 MJ/kg
LPG 34-52MJ/kg

The main problem with hydrogen is cost of production, either by heat intensive hydrogen reformation (to refine it from natural gas or methane) or electrically intensive electrolysis (from seawater). It also leaks too easily (simplest atom) presenting infrastructure and storage challenge, especially given the pressures required to move the required volumes of hydrogen around the system. That is perhaps what your combustion engineer friend was referring to, Hydrogen is so light the infrastructure needs to cope with high volumes.

Neither problem is insurmountable, if the production processes can be powered by renewable energy. There are projects already under consideration to produce hydrogen by directly electrolysing seawater at the base of huge offshore wind turbines using the turbines own energy.

There will always be applications requiring fuels with much higher energy densities than batteries are likely to be able to offer on the near future. Aircraft of all types, helicopters, long range drones, ocean going boats and all forms of transport in large and/or less developed countries where distances can be vast, and the consequences of running out of fuel potentially severe.

Anyway, apologies for thread hijack. Back to the issue (or non issue) of pre-cat ingestion

Edited by Calinours on Tuesday 30th May 12:24

[karatemaserati]

On the subject of the well known independent who explains the problem and sells the cure, I think suggesting its a conflict of interest is a slightly cynical point of view and doesn't stack up... from a business aspect they'd be better off if they didn't offer the cure and just went on coining it from coil/plug changes and engine rebuilds.

[jason61c]

karatemaserati said:

On the subject of the well known independent who explains the problem and sells the cure, I think suggesting its a conflict of interest is a slightly cynical point of view and doesn't stack up... from a business aspect they'd be better off if they didn't offer the cure and just went on coining it from coil/plug changes and engine rebuilds.

They probably wouldn’t make as much money.