Early DB9 engine reliabilty

[paulrog1]

Hi
I just want to know if you guys have any information regarding the early DB9 engines and specifically the piston slap and small end bearing wear that affected a forum member on here causing a very expensive engine rebuild.
Ok so we know that the very early ones were built by cosworth from 2004 to mid 2005, after then after that manufactured in Germany, then around 2008 (please correct me if I'm wrong) the small ends had a design revision to eliminate this problem.
So my questions are-
Are the engines built in the UK upto mid 2005 by cosworth more prone to the above issue?? Or are all engines manufactured upto 2008 prone to this issue?
I suppose what im trying to get at is there a difference in purchasing a DB9 from 2004 to 2007 in regard to the above issue???

Thanks for your help.

[PrAston]

paulrog1 said:

Hi
I just want to know if you guys have any information regarding the early DB9 engines and specifically the piston slap and small end bearing wear that affected a forum member on here causing a very expensive engine rebuild.
Ok so we know that the very early ones were built by cosworth from 2004 to mid 2005, after then after that manufactured in Germany, then around 2008 (please correct me if I'm wrong) the small ends had a design revision to eliminate this problem.
So my questions are-
Are the engines built in the UK upto mid 2005 by cosworth more prone to the above issue?? Or are all engines manufactured upto 2008 prone to this issue?
I suppose what im trying to get at is there a difference in purchasing a DB9 from 2004 to 2007 in regard to the above issue???

Thanks for your help.

I'm not entirely sure when they changed the small end bearings, but the FSA for the shorter dipstick came out in May 2008 and covers up to chassis 10286. In my view, and some others, this was a band-aid/cover-up for the bearing issue, so my guess is that the bearing change was made around the same time. It may be hard to find out exactly when that happened. Aston probably kept quiet about it because announcing it would be a tacit admission that there was a problem with the earlier design.

That said, I have only heard of the ticking issue affecting DB7V's and very early DB9's. I can't recall reading about it in anything later than a 2005. I'm not sure the problem ended when Cosworth stopped building the engines but the timing does seem to line up that way. Engine manufacture changed from Cosworth to Germany around chassis 1790, and Cosworth engines are numbered AM04/0XXXX, while German ones are AM04/1XXXX.

I was absolutely insistent about getting an early car with a UK-made, Cosworth engine, and I'm paying the price because I got one that ticks. If you're not concerned about where your engine was made, then later is probably better. In the range you mention, the 07 would be the one to go for if for no other reason than the better seats.

[paulrog1]

Thanks for your message, what mileage has yours done? Has it been driven hard or tracked alot? Could i ask what is your chassis number? Plus are you thinking about getting it repaired? If so any quotes?

Thanks.

[BamfordMike]

PrAston said:

In my view, and some others, this was a band-aid/cover-up for the bearing issue.

I was absolutely insistent about getting an early car with a UK-made, Cosworth engine, and I'm paying the price because I got one that ticks.

In comment to your first point, the theory you suggest would be that an increase to oil volume in the sump, so naturally a corresponding sump oil level / height increase [what the short dipstick delivered], will help oil flow within the small end bush? When it’s actually the piston squirter jets supplying oil to the underside of the piston crown which feeds a small amount of oil to the bush. The squirter jets are fed off main gallery oil supply and in normal conditions sump oil level height / volume has zero effect on availability of oil in the main gallery. It’s also worth remembering the baffle and scraper plate which sits underneath the crankshaft pretty much stops bottom end oil splash feed upwards. Those points means oil level and volume in the sump has zero relation to oil feed to the small end bearing bush.

The short dipstick was introduced as a sticking plaster to help prevent the engine seizing because the oil level on some cars dropped too low, and / when during service interval oil level was unchecked by the driver. The unfortunate conclusion was a seized up or damaged beyond repair crankshaft / bearings / rods (remembering all those components are bombproof, they only failed because the motor ran low on oil). The reason oil consumption was high was because oil breather circuit one-way valve failure caused oil carry-over into the inlet manifold at something like a rate of 0.5L per 1k miles, meaning the engine would slowly consume oil until failure. The sticking plaster / the short dipstick helped by simply giving more oil, buying extra time which might be enough for the oil level to be checked and overt the failure (yep, a proper sticking plaster fix, not addressing root cause but attending to the symptom).

The (dredded) DB9 tick is worn liners, ovality causing piston slap. With liners perfectly in service (no piston slap) and even with a bit of a sloppy piston pin / little end bush, the noise created from that small-end in isolation to any other wear, would not be significant as to cause concern, and as engine speed increased off idle, that slight small end noise would be drowned out by other general mechanical noise. There are plenty of early DB9’s I know which have +80/100k on the original plain small end bush and don’t exhibit rattle. The bush evolution is indeed a better design, but the straight cut bush without an internal oil channel isn’t a ticking time bomb absolutely destined to failure.

I’m sorry you have the tick, but it’s almost certainly liner ovality and not the small end bush in isolation.

[macdeb]

I'm all ears here, as one day I'd maybe like a V12 Vantage. I would not however want a car that had been tracked regular.

[BamfordMike]

paulrog1 said:

If so any quotes?

Thanks.

Whilst the factory is selling remanufactured engines at approx £8800+vat, the route to repair which is easiest and hassle free (apart from the cost) is the replacement motor, labour and fluids.

If a rebuild of old motor, each liner remachine is approx £300 per pot, piston kit and rod £300 ish per pot, a crankshaft at approx. £2500, then the labour to build the motor and gaskets / bearings, all means a motor rebuild when a lot of new parts is required is definitely the uneconomical route to repair.

I say whilst the factory is selling reman engines.... because I’m sure that contract won’t last forever.

[paulrog1]

BamfordMike said:

In comment to your first point, the theory you suggest would be that an increase to oil volume in the sump, so naturally a corresponding sump oil level / height increase [what the short dipstick delivered], will help oil flow within the small end bush? When it’s actually the piston squirter jets supplying oil to the underside of the piston crown which feeds a small amount of oil to the bush. The squirter jets are fed off main gallery oil supply and in normal conditions sump oil level height / volume has zero effect on availability of oil in the main gallery. It’s also worth remembering the baffle and scraper plate which sits underneath the crankshaft pretty much stops bottom end oil splash feed upwards. Those points means oil level and volume in the sump has zero relation to oil feed to the small end bearing bush.

The short dipstick was introduced as a sticking plaster to help prevent the engine seizing because the oil level on some cars dropped too low, and / when during service interval oil level was unchecked by the driver. The unfortunate conclusion was a seized up or damaged beyond repair crankshaft / bearings / rods (remembering all those components are bombproof, they only failed because the motor ran low on oil). The reason oil consumption was high was because oil breather circuit one-way valve failure caused oil carry-over into the inlet manifold at something like a rate of 0.5L per 1k miles, meaning the engine would slowly consume oil until failure. The sticking plaster / the short dipstick helped by simply giving more oil, buying extra time which might be enough for the oil level to be checked and overt the failure (yep, a proper sticking plaster fix, not addressing root cause but attending to the symptom).

The (dredded) DB9 tick is worn liners, ovality causing piston slap. With liners perfectly in service (no piston slap) and even with a bit of a sloppy piston pin / little end bush, the noise created from that small-end in isolation to any other wear, would not be significant as to cause concern, and as engine speed increased off idle, that slight small end noise would be drowned out by other general mechanical noise. There are plenty of early DB9’s I know which have +80/100k on the original plain small end bush and don’t exhibit rattle. The bush evolution is indeed a better design, but the straight cut bush without an internal oil channel isn’t a ticking time bomb absolutely destined to failure.

I’m sorry you have the tick, but it’s almost certainly liner ovality and not the small end bush in isolation.

So if its not the small end bearing that causes the piston slap what causes it??

Is it just random? Or maybe driving style? Some owners drive them harder than others? So to prevent it maybe you just can't put your foot down.

Maybe the cars which have reached 80-100K miles with no problem have been driven carefully?

Paul.

[cayman-black]

macdeb said:

I'm all ears here, as one day I'd maybe like a V12 Vantage. I would not however want a car that had been tracked regular.

I believe this problem does not affect the V12V. ? Imo very few V12V are tracked also.

[PrAston]

BamfordMike said:

In comment to your first point, the theory you suggest would be that an increase to oil volume in the sump, so naturally a corresponding sump oil level / height increase [what the short dipstick delivered], will help oil flow within the small end bush? When it’s actually the piston squirter jets supplying oil to the underside of the piston crown which feeds a small amount of oil to the bush. The squirter jets are fed off main gallery oil supply and in normal conditions sump oil level height / volume has zero effect on availability of oil in the main gallery. It’s also worth remembering the baffle and scraper plate which sits underneath the crankshaft pretty much stops bottom end oil splash feed upwards. Those points means oil level and volume in the sump has zero relation to oil feed to the small end bearing bush.

The short dipstick was introduced as a sticking plaster to help prevent the engine seizing because the oil level on some cars dropped too low, and / when during service interval oil level was unchecked by the driver. The unfortunate conclusion was a seized up or damaged beyond repair crankshaft / bearings / rods (remembering all those components are bombproof, they only failed because the motor ran low on oil). The reason oil consumption was high was because oil breather circuit one-way valve failure caused oil carry-over into the inlet manifold at something like a rate of 0.5L per 1k miles, meaning the engine would slowly consume oil until failure. The sticking plaster / the short dipstick helped by simply giving more oil, buying extra time which might be enough for the oil level to be checked and overt the failure (yep, a proper sticking plaster fix, not addressing root cause but attending to the symptom).

The (dredded) DB9 tick is worn liners, ovality causing piston slap. With liners perfectly in service (no piston slap) and even with a bit of a sloppy piston pin / little end bush, the noise created from that small-end in isolation to any other wear, would not be significant as to cause concern, and as engine speed increased off idle, that slight small end noise would be drowned out by other general mechanical noise. There are plenty of early DB9’s I know which have +80/100k on the original plain small end bush and don’t exhibit rattle. The bush evolution is indeed a better design, but the straight cut bush without an internal oil channel isn’t a ticking time bomb absolutely destined to failure.

I’m sorry you have the tick, but it’s almost certainly liner ovality and not the small end bush in isolation.

I didn't mean to imply that the oil level and the ticking were directly related, but the timing of the dipstick change and the bearing redesign is a curious coincidence. My theory was that in a case of low or marginal oil level, the small ends, being one of the last things line as far as oiling, might be the weakest link. I was also assuming, incorrectly, that the rods were drilled for positive oiling.

The big question to my mind is, if liner ovality causes ticking, what causes liner ovality?

[PrAston]

paulrog1 said:

Thanks for your message, what mileage has yours done? Has it been driven hard or tracked alot? Could i ask what is your chassis number? Plus are you thinking about getting it repaired? If so any quotes?

Thanks.

It's just about to turn 20,000 miles. I don't know how the first owner drove it, but the second owner seemed to treat it well, and I drive it like Miss Daisy's undertaker. My chassis number is 1379.

I looked into getting it repaired, but I'm in three minds about it. It's a lot of money to spend on a car I probably still won't trust, but I'd lose just as much if I sold it with disclosure, and I certainly don't get much enjoyment out of it as-is. The only estimate I got was from Bamford Rose's US partner in Arizona. As I recall it was between $18-23k depending on what they find when they open the engine.

[Ryanr317]

PrAston said:

It's just about to turn 20,000 miles. I don't know how the first owner drove it, but the second owner seemed to treat it well, and I drive it like Miss Daisy's undertaker. My chassis number is 1379.

I looked into getting it repaired, but I'm in three minds about it. It's a lot of money to spend on a car I probably still won't trust, but I'd lose just as much if I sold it with disclosure, and I certainly don't get much enjoyment out of it as-is. The only estimate I got was from Bamford Rose's US partner in Arizona. As I recall it was between $18-23k depending on what they find when they open the engine.

I'm in the U.S. as well, in Florida. I haven't seriously looked into repair yet but that's a pretty significant cost. The tick is annoying but I would live with it if the repair is near half of what the car is worth.

[macdeb]

cayman-black said:

macdeb said:

I'm all ears here, as one day I'd maybe like a V12 Vantage. I would not however want a car that had been tracked regular.

I believe this problem does not affect the V12V. ? Imo very few V12V are tracked also.

[macdeb]

cayman-black said:

macdeb said:

I'm all ears here, as one day I'd maybe like a V12 Vantage. I would not however want a car that had been tracked regular.

I believe this problem does not affect the V12V. ? Imo very few V12V are tracked also.

[BamfordMike]

PrAston said:

My theory was that in a case of low or marginal oil level, the small ends, being one of the last things line as far as oiling, might be the weakest link. I was also assuming, incorrectly, that the rods were drilled for positive oiling.

The big question to my mind is, if liner ovality causes ticking, what causes liner ovality?

Indeed, positive oil fed connecting rods made from sintered construction would be impressive!
The small ends being one of the first parts to receive a splash of oil because piston underside squirter jets are fed from the main oil gallery, and a splash of oil from big end journals will arrive at the small end too, means any thinking of insufficient oil supply and an increase of oil volume will help-out, is barking up the wrong tree. If the oil is insufficient, it’s the last in the feed, the big end journals 6/12 which will seize / wear firstly, hence the short dipstick buying time to avoid that type of failure.

The revision of a channel inside the small end bearing does help-out however, and a sloppy piston pin / small end isn’t seen on later engines, but in isolation to any other issues, I’m doubtful the wear seen in small end would amount to a decision to pull the motor.

I’m unsure if there was a change in liner spec or block casting / materials between uk built engines and AMEP, but the way the early DB9 liners wear oval for the little mileage used cannot be put down to normal wear and tear. But it’s pretty much futile to question why, the problem just needs fixing and move on.... it won’t happen again on a rebuilt motor on account the liner will most likely be replaced with the very best ductile material money can buy, and the little end will be evolved to the newer part.

In all the engines we’ve rebuilt, yet to come across small end wear without liner ovality at the same time, including a memorable blue DB7 GT, which had the small end rectified but not the liners, but on running the engine after rebuild the engine exhibited the exact same ticking sound which was the very reason the engine came apart in the first place. Eventually the engine was sorted by a proper builder who measured the liner ovality.

[paulrog1]

I'm trying to find out how common this is on the cosworth built DB9 engines.

Mike - How many DB9 cosworth built engines have you repaired? also the people which have contacted you about this ticking sound?

I'm guessing there's not alot of garages which would do this work, maybe McGurks, and Works? wonder how many DB9 engines they have replaced?, Plus the overseas cars (there are 2 USA cars on this thread with the ticking sound)

So looks like there were 1750 (ish) DB9 cars with the cosworth engines before the engines were built in Germany, be interested to know if this is rare or common issue.

Thanks.

[SFTWend]

Wondering if these potential issues were rectified by the time of the 2009 MY 470bhp engine?

[PrAston]

BamfordMike said:

Indeed, positive oil fed connecting rods made from sintered construction would be impressive!
The small ends being one of the first parts to receive a splash of oil because piston underside squirter jets are fed from the main oil gallery, and a splash of oil from big end journals will arrive at the small end too, means any thinking of insufficient oil supply and an increase of oil volume will help-out, is barking up the wrong tree. If the oil is insufficient, it’s the last in the feed, the big end journals 6/12 which will seize / wear firstly, hence the short dipstick buying time to avoid that type of failure.

I’m unsure if there was a change in liner spec or block casting / materials between uk built engines and AMEP, but the way the early DB9 liners wear oval for the little mileage used cannot be put down to normal wear and tear. But it’s pretty much futile to question why, the problem just needs fixing and move on.... it won’t happen again on a rebuilt motor on account the liner will most likely be replaced with the very best ductile material money can buy, and the little end will be evolved to the newer part.

The small ends would seem to me to be under an awful lot of strain to rely on splash lubrication, but drilled rods are a lot less common than I thought they were. I guess it works well enough in most applications.

I don't think it's futile to question why the liners go oval, if for no other reason than someone with an early DB9 that doesn't tick yet might be interested in taking steps to prevent it.

I sent an oil sample from my engine to be analyzed, and it came back with normal metal levels and no indication of abnormal wear. Could the ovality be a function of something other than wear? Warping from heat perhaps? The member who documented his trials with a ticking DB9 seemed to think overheating was a contributing factor.

[BamfordMike]

SFTWend said:

Wondering if these potential issues were rectified by the time of the 2009 MY 470bhp engine?

Ive not heard the dreaded DB9 tick on a 470 / 510 motor, so far. I think it’s more a case of either a material spec or a production process which caused the issue on early DB9’s (which was unknown to the factory at the time), was by chance ‘engineered out’ at the change over of production location / process / suppliers

[BamfordMike]

PrAston said:

The small ends would seem to me to be under an awful lot of strain....

..... might be interested in taking steps to prevent it.

I sent an oil sample from my engine to be analyzed, and it came back with normal metal levels and no indication of abnormal wear. Could the ovality be a function of something other than wear? Warping from heat perhaps? The member who documented his trials with a ticking DB9 seemed to think overheating was a contributing factor.

The rods aren’t under that much strain really. It’s a low revving way more than sub 100bhp per litre engine. I guess it’s more the case that the liner wear creates abnormal loading on the pin / little end which accelerates wear, hence my comment that I’ve not seen little end wear separate to ovality and it’s the ovality tick which causes the motor to be pulled, but I could be wrong.

It’s a bit futile to dissect the reasons why the problem occurs because the only preventive course of action is to either not drive or sell the car, which both are unnecessary and drastic moves when there are the vast majority of that same era car even with high miles which don’t exhibit the problem. Fix it and move on is pretty much the only course of action, and with a decent fix, the issue won’t reoccur.

I’d bet on warping from heat too (cars where the motor has had a hard life). But to research that further would need the liner carefully machining out of the parent bore, and signs of ovality measured in the block / parent bore which in turn distorted the liner. It’s a curious distortion because across one plain we see the liner wearing oversize, but another plain the liner significantly tightens, so it’s not normal thrust / anti thrust wear.

[BamfordMike]

paulrog1 said:

I'm trying to find out how common this is on the cosworth built DB9 engines.

Mike - How many DB9 cosworth built engines have you repaired? also the people which have contacted you about this ticking sound?

I'm guessing there's not alot of garages which would do this work, maybe McGurks, and Works? wonder how many DB9 engines they have replaced?, Plus the overseas cars (there are 2 USA cars on this thread with the ticking sound)

So looks like there were 1750 (ish) DB9 cars with the cosworth engines before the engines were built in Germany, be interested to know if this is rare or common issue.

Thanks.

Of the 1750, id guess approx 1000 were UK cars (soft launch put most cars into UK initially), if the problem effected even 25% of those cars, forums like this would no doubt report / complain of the issue much more frequently than current? But saying that, how many engines that were destined to tick didn’t suffer low oil level and fail, or had misfire and ingested catalysts and failed prior to developing a tick - we’ll never know.

But scrap paper calculations, we’ve rebuilt more engines due to catalyst ingestion and low oil level than correcting the dreaded tick, so if there is no sign of tick at pre purchase inspection, and mileage was less than, say, 30k over next 10 years, it’s not a problem which should trouble most owners.

Pretty much any garage can take the work on, because at the moment the factory sells a remanufactured engine for about £9k plus the dreaded (great value for money imho) making the repair an easy engine swap. That figure makes it pretty much impossible and not cost effective (for the owner) to rebuild the old motor for a lower price when significant new parts are required. No doubt one day the factory will stop supplying remanufactured engines, then will come the time that there will be no alternative to a rebuild and it will cost significantly more than the remanufactured engine route to repair.