V12 Strip down video
Discussion
Whilst browsing around for various DB9 info I came across this video
http://www.youtube.com/watch?v=pzmL2rl1j8Q
It details a fault with a low miles V12 causing the rear two pistons to break catastrophically. From 07:30 onwards shows the engine and transmission separated from the car and they then take the heads off and strip down the sump. I am not going to lose sleep over the issue as my car has done 37k miles but I found seeing the engine away from the car very interesting. The comments near the end regarding the quality of the pistons and con rods was an eye opener to.
I am only posting this as an interesting view of the V12 not a dire warning about potential issues.
http://www.youtube.com/watch?v=pzmL2rl1j8Q
It details a fault with a low miles V12 causing the rear two pistons to break catastrophically. From 07:30 onwards shows the engine and transmission separated from the car and they then take the heads off and strip down the sump. I am not going to lose sleep over the issue as my car has done 37k miles but I found seeing the engine away from the car very interesting. The comments near the end regarding the quality of the pistons and con rods was an eye opener to.
I am only posting this as an interesting view of the V12 not a dire warning about potential issues.
It would be interesting to see the follow up to that, but I have not heard of any other catastrophic failures of the V12?
Also Ford engines are generally bulletproof and regardless of what the guy says, he has never worked on an Aston V12 before, so he is summising plenty, with no hard facts. As for garbage internals, I agree what he is fitting is better, but what was fitted has probably been through many 10's 000 miles of testing at full throttle and has proven to be up to the job. Who knows that the owner may not have run it short on oil, then topped it up and the damage was already done?
Very interesting though, shame for the owner.
Also Ford engines are generally bulletproof and regardless of what the guy says, he has never worked on an Aston V12 before, so he is summising plenty, with no hard facts. As for garbage internals, I agree what he is fitting is better, but what was fitted has probably been through many 10's 000 miles of testing at full throttle and has proven to be up to the job. Who knows that the owner may not have run it short on oil, then topped it up and the damage was already done?
Very interesting though, shame for the owner.
I'm guessing this is an early DB9 in the video. It is obvious that Aston knew about the problem of low oil level since they then issued a service bulletin to replace the dipstick with a shorter one, thereby requiring a higher level in the pan.
The piston issue is a red herring. The pistons didn't fail because of low quality, they failed because of insufficient oiling. You can put all the Ti rods and forged pistons you want in the motor, and they won't prevent catastrophic damage if the oil disappears.
Corvette Z06 motors use forged pistons and Ti conrods and still their motors have grenaded when used for track days due to momentary oil pressure drop in high G turns (right hand IIRC). And this is a car with 'race' dry sump system. And in this case, while the car has an oil pressure sensor, it didn't respond to these momentary pressure drops, it was only discovered by installing a pressure sensor and high speed data logger. So even if the Aston had an oil pressure sensor, who's to say that it would even register such a problem?
Bottom line: No oil = no engine
The piston issue is a red herring. The pistons didn't fail because of low quality, they failed because of insufficient oiling. You can put all the Ti rods and forged pistons you want in the motor, and they won't prevent catastrophic damage if the oil disappears.
Corvette Z06 motors use forged pistons and Ti conrods and still their motors have grenaded when used for track days due to momentary oil pressure drop in high G turns (right hand IIRC). And this is a car with 'race' dry sump system. And in this case, while the car has an oil pressure sensor, it didn't respond to these momentary pressure drops, it was only discovered by installing a pressure sensor and high speed data logger. So even if the Aston had an oil pressure sensor, who's to say that it would even register such a problem?
Bottom line: No oil = no engine
The guy did state that the sump was about 3/4 full when drained but then as we all know it's a double sump, and most of the oil he drained was probably from the rear end away from the pickup.
It is interesting and not surprising that AM did not do more.
If I was in charge over at AM I would have paid for this engine to be returned so that it could be properly inspected and diagnosed.
Of course it could very well have been a defective con rod or bearing cap that gave way, things do break no matter how good they are.
It is interesting and not surprising that AM did not do more.
If I was in charge over at AM I would have paid for this engine to be returned so that it could be properly inspected and diagnosed.
Of course it could very well have been a defective con rod or bearing cap that gave way, things do break no matter how good they are.
The comment regarding the oil being three quarters full mean nothing as he didn't qualify what he meant and we don't know whether the sump is intended to be 75% full or 100% full.
He did mention the filters being full of oil and showed how much was in the exhaust. Much oil would have been lost down the exhaust pipe and we shall never know how much.
However, having said the above, is it likely that a new engine would/should lose enough oil in 9000 miles to cause that to happen without some sort of warning. Would be interesting to see if there are any fault codes stored as presumably it would have stored a low oil warning.
I am no engine builder but if what he says about the standard of the stock pistons is true then its shocking for such a supposedly top end car to be built with run of the mill components..
Surely the owner should be looking to recover costs from AM I would have a bash if it were me.
That said the mechanic and his mates appear to be sensationalising for TV and we don't know the facts.
What I do know if the TV programme would have been 5 minutes shorter if they had edited out the words Obviously and actual.
He did mention the filters being full of oil and showed how much was in the exhaust. Much oil would have been lost down the exhaust pipe and we shall never know how much.
However, having said the above, is it likely that a new engine would/should lose enough oil in 9000 miles to cause that to happen without some sort of warning. Would be interesting to see if there are any fault codes stored as presumably it would have stored a low oil warning.
I am no engine builder but if what he says about the standard of the stock pistons is true then its shocking for such a supposedly top end car to be built with run of the mill components..
Surely the owner should be looking to recover costs from AM I would have a bash if it were me.
That said the mechanic and his mates appear to be sensationalising for TV and we don't know the facts.
What I do know if the TV programme would have been 5 minutes shorter if they had edited out the words Obviously and actual.
Tyre Tread said:
That said the mechanic and his mates appear to be sensationalising for TV and we don't know the facts.
Spot onHim & his mate constantly repeat themselves and makes unsubstantiated claims
Calling Gaydon from the US to ask fo assistance with diagnosing a failed V12 when you are not an authorised technician is hardly going to prompt cooperation (I wonder why the owner didn't take it to AM?)
How the hell does he know it is a design fault?
It only takes seconds for an engine run low on oil to do terminal damage and it often doesn't show until it fails. Often it block the oil pick up or filter causing this sort of major failure as a consequence rather than the root cause.
That has failed at low speed or the block would have been punctured.
With the weight and torque in that engine that crank will probably be bent.
I'd not be happy rebuilding that ther could be all sorts of rubbish hung up in the oil galleries.
Plus the conditions they are attempting to rebuild it in are preety poor, I wonder how long it lasted afterwards?
Apparently the DB9 is a race car as well and Aston should have used race parts in the engines
Can I have the 21 minutes back please
Tyre Tread said:
However, having said the above, is it likely that a new engine would/should lose enough oil in 9000 miles to cause that to happen without some sort of warning. Would be interesting to see if there are any fault codes stored as presumably it would have stored a low oil warning.
The V8 is know to use oil when driven hard.My last roadster used 2.5 litres in 12 days & 3400 miles around France
I've already put a litre in my S in 1400 miles
I wouldn't be surprised to see the same in the V12
I wonder if the US owner ever did any traffic light GP's or 1/4 miles
That would force the already low oil level to the back of the pan away from the pick up.
Only needs to happen for a short period a couple of times and it is down hill from there
mikey k said:
The V8 is know to use oil when driven hard.
My last roadster used 2.5 litres in 12 days & 3400 miles around France
I've already put a litre in my S in 1400 miles
I wouldn't be surprised to see the same in the V12
If you want to see really sMy last roadster used 2.5 litres in 12 days & 3400 miles around France
I've already put a litre in my S in 1400 miles
I wouldn't be surprised to see the same in the V12
te oil consumption have a look at the 1.4 TSI engine in the Polo GTI 
Oh, and the comments that the DB9 is a race car (another stupid Americanism, should be RACING car)
mikey k said:
Can I have the 21 minutes back please
That video could have been edited down to 10mins.Just to show the quality of his workmanship, he proceeded to remove the old piston out of the block with a pry bar resting on the block face, for him to then comment " there is nothing wrong with the block so we don't need to get a new one" now any quality mechanic knows you never use the gasket face to leaver against, and remove the broken piston out of the bottom of the block.
I think the reason were yet to see the follow up video is due to loss of compression from some t
t damaging the the block face and they can't get the thing running!johng39 said:
Wise stuff.
I have just wasted 21 mins of my life watching that vid. what complete garbage..... blind leading blind.... i want my 21 mins back..... can i start a civil law case for that 
oil starvation..... ummmm.... stuff gets incredibly hot which means it gets incredibly BLUE. All that engine internal metal looked very shiny to me. If it was oil starvation to crank journal, the crank journal pin would be blue, the bearings would resemble a thin blue chewed up piece of metal, and they dont - there is simply no evidence of heat build up. So, a few second review of the parts shows oil starvation was not root cause of that particular failure.
My guess...... Well firstly its not oil starvation.... (just thought i would repeat that a few times
)The piston is cracked across the top land / crown. This is caused by over pressure, in most cases knock or detonation over pressure. If the rod seizes on crank journal the shear point is at piston small end boss leaving piston crown in one piece. If the piston seized in the bore then the piston would be in a million pieces, not cracked.
The rear two cylinders happen to be the most knock sensitive because they are furthest away from oil pump / coolant pump, therefore not getting coolest coolant and oil. For whatever reason detonation has occurred (perhaps low octane fuel filled in error) and pressure failed the piston. The complete mess and debris in the bottom of the sump is because after point of failure someone has driven, and driven, and driven, and driven, and driven the car until it wont drive no more - probably they thought poorly engines self heal......
Any engine can be built with better quality parts, what the return for that extra spend actually is must be questioned. The parts built into the engine to start with passed sign-off tests necessary to fulfill durability sign-off standards - simple as....
i do agree with one point mentioned - there should be safety systems to prevent the engine eating itself. Knock detection might have stopped this failure, oil pressure and level warning will help oil level related problems - which do occur.
in absence of these measures, fill with correct fuel, top the oil and coolant up and inspect as instructed by handbook and problems such as this are unlikely to occur.
We have seen a few failed V12's that need rebuild - happens but is not widespread (like premature V8 clutch failure is), but in all cases root cause was misuse or abuse....
I sort of see why the factory was not interested in helping out / being involved - They must take the view point that not withstanding misuse or abuse the product has been validated, without question, not to fail. This means that the factory is solid and sure there is nothing to learn and apply across the board from this episode,, if the car is out of warranty there is no obligation either - stern but fair.... but you would be surprised the amount of folk who run the engine out of oil, seize it and try and make a claim. The giveaway is dirty oil in the system, fresh oil in the sump - even easier to spot on a dry sump V8...
Edited by BamfordMike on Wednesday 7th March 00:19
Edited by BamfordMike on Wednesday 7th March 00:24
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