why do coilpacks fail???

[speedee911]

why do they fail? and is it normal for them to go all at once? three of mine failed in the last week.. is there something i can do to prevent future failures?

[Maverick]

because the stealership can make money out of this deal. they have a sh*t load instock for you to call and order some if you don't keep spare ones

[dougyfresh]

Maybe due to the heat? They are, effectively, ignition coils that are packaged into a small object that sits inside the cylinder head. Lots of heat in our engines. Heat and electrical devices typically don't fair too well in regards to long term durability.

As a result they (Audi/VW) continuously are updating the coil packs with new revisions. I am not sure what the most current revision is. I have revision "R" that I bought in late 2006. I bought mine from the VW dealership for around $30 a coil pack.

[MikTip]

Heat.

Cyclic heat.

The electronics inside the coils have to be able to withstand the heat, and high voltages
for many, many cycles.

[Tgr_Clw]

why do they fail?

Why do people die?

Just accept the fact that they do (can be applied to both people and coilpacks).

[PRY4SNO]

Heat.

Cyclic heat.

The electronics inside the coils have to be able to withstand the heat, and high voltages for many, many cycles.

This is a great question... never thought to ask so myself.

Can you explain cycles? As in duty cycle, from when it becomes energized to it being non-energized? Is that from the time when you turn the car over to the time you shut it down, or is it referring directly to each ignition within the cylinder?

Thanks!

[koolade9]

This is a great question... never thought to ask so myself.

Can you explain cycles? As in duty cycle, from when it becomes energized to it being non-energized? Is that from the time when you turn the car over to the time you shut it down, or is it referring directly to each ignition within the cylinder?

Thanks!

cycle = charge to discharge... so at idle, around 400-450 cycles/min.

This got me thinking about heat, and it's affect on coilpack failure (I have a 3.0 and don't necessarily care)...

but has anyone looked into any trends with this problem.

As a baseline, is everyone using healthy, properly gapped plugs?

How about geographic location/ambient temperature, do folks in AZ and NV go through more coilpacks then say, folks in MN or Canada?

Anyone looked into lowering under-hood temps? (I've never seen a vented hood for a B6.)

How about mods/additions... Obviously more boost is going to equal higher under-hood temperatures, amongst other things. Have these failures been more prevelant on the heavily modded vehicles? DSMs max out the stock ignition at pretty high boost/rpm levels. Are we reaching a relativly short limit to the oem ignition system? If so, is there potential for an aftermarket solution?

On the same topic, how solid is the tune on these modded cars? A lean condition &/or knock can raise temps. Does the OEM ecu have any control over the duration of ignition?

Is everyone still on the stock redline? How often are you frequenting the higher rpm ranges?

Perhaps an honest trend analysis is in order to provide better accuracy as to the cause/solution to this problem...thoughts?

[PRY4SNO]

cycle = charge to discharge... so at idle, around 400-450 cycles/min.

This got me thinking about heat, and it's affect on coilpack failure (I have a 3.0 and don't necessarily care)...

but has anyone looked into any trends with this problem.

As a baseline, is everyone using healthy, properly gapped plugs?

How about geographic location/ambient temperature, do folks in AZ and NV go through more coilpacks then say, folks in MN or Canada?

How about mods/additions... Obviously more boost is going to equal higher under-hood temperatures, amongst other things. Have these failures been more prevelant on the heavily modded vehicles? DSMs max out the stock ignition at pretty high boost/rpm levels. Are we reaching a relativly short limit to the oem ignition system? If so, is there potential for an aftermarket solution?

On the same topic, how solid is the tune on these modded cars? A lean condition &/or knock can raise temps. Does the OEM ecu have any control over the duration of ignition?

Is everyone still on the stock redline? How often are you frequenting the higher rpm ranges?

Perhaps an honest trend analysis is in order to provide better accuracy as to the cause/solution to this problem...thoughts?

- .034" gap

- altitude = ~ 3,750' or (~ 1,150m)

- tune = Unitronic = ROCK SOLID (except one niggling underboost issue)... no knock or lean conditions

- 7,000 rpm redline, seen about 1-3 times/month Over 5k rpm... LOL, daily.

I've only had two CPs go, one right after getting the car reflashed and again after a long, wintertime mountain road-trip. Since replaced all with STI coils and been running like a champ! And nearly 150,000 km on the clock!

Well, there's my two cents, who else wants to participate in the trend analysis?

[Tgr_Clw]

This got me thinking about heat, and it's affect on coilpack failure (I have a 3.0 and don't necessarily care)...

You think because you have a 3.0 you're immune from coilpack failures?
Ha.

[infernocl]

nearly everything on VAG vehicles fail for the same reason, poor outsourcing manufacturers.

quality control for VAG vehicles at the tier 1 and tier 2 manufacturing level is absolutely terrible. the parts are originally designed functionally more more show than go. although strict R&D take place in the designs, tier 2 and tier 3 manufacturers make terrible parts that gets passed off to final assembly. my friends asked the dutch/german engineers about the poor quality of german parts and reasons they keep them, sadly the answer is because "they're there".

having friends in the manufacturing business for multiple car companies including VW, MB, mitsu, they basically say VW parts are garbage and should be scrapped. in fact, the parts made in germany show lower casting qualities than their chinese counterparts, but chinese parts are poorly measured and tooled. so german parts are made of crap and chinese parts are made like crap.

that what happens when VAG picks their manufacturers because "they're there". really that is it, they don't care about who makes better parts, they give them business because it's convenient. everyday i wish my pretty audi electrics are made by denso.

[dougyfresh]

nearly everything on VAG vehicles fail for the same reason, poor outsourcing manufacturers.

quality control for VAG vehicles at the tier 1 and tier 2 manufacturing level is absolutely terrible. the parts are originally designed functionally more more show than go. although strict R&D take place in the designs, tier 2 and tier 3 manufacturers make terrible parts that gets passed off to final assembly. my friends asked the dutch/german engineers about the poor quality of german parts and reasons they keep them, sadly the answer is because "they're there".

having friends in the manufacturing business for multiple car companies including VW, MB, mitsu, they basically say VW parts are garbage and should be scrapped. in fact, the parts made in germany show lower casting qualities than their chinese counterparts, but chinese parts are poorly measured and tooled. so german parts are made of crap and chinese parts are made like crap.

that what happens when VAG picks their manufacturers because "they're there". really that is it, they don't care about who makes better parts, they give them business because it's convenient. everyday i wish my pretty audi electrics are made by denso.

Very nicely stated. Quality control for suppliers is a tough feat. The Auto industry isn't the only industry that this is noticeable within. One would think the aerospace industry is better given strict requirements and regulations. Well, scrap rates for non-conforming parts are excessively high. Good news is the manufacturers scrap the parts before they get out into the field. Well, 99.9% of the parts....





cycles.... I think he is referring to heat cycles as opposed to electrical energizing cycles. The simplest heat cycle is starting the car, running at operating temp, and cooling down.

[koolade9]

You think because you have a 3.0 you're immune from coilpack failures?
Ha.

thanks for jinx'ing me...

[PRY4SNO]

cycles.... I think he is referring to heat cycles as opposed to electrical energizing cycles. The simplest heat cycle is starting the car, running at operating temp, and cooling down.

Nice, thanks.

Now, just because I'm an anal sonofabitch, can someone please confirm this?

[Joesturbo]

Nice, thanks.

Now, just because I'm an anal sonofabitch, can someone please confirm this?

I posted this up this past weekend.... Gets me thinking what about putting a heat sink on top of them - like from a PC???

OK, a while back I had a coil pack blow when it was under warranty... I noticed that the coil pack had rust on it, like it was exposed to moisture. I do know the engine was steam cleaned when I purchased it, but did not think anything about it.

So visiting mom-in-law, driving to Home Depot to get some pluming supplies, the A4 starts to run funny (loss of power), then total melt down... Starts missing on a cylinder and check engine light (CEL) came on. So I luckily had my laptop and trusty vag-com cable with me. So checked it out, and sure enough bank 3 was toast - swapped it to number 2 and the code followed - Coil pack failure for sure.

I was not near a dealer and made two quick painful stops.
1. Autozone $33
2. Advanced Auto $66

I ended up buying the one from Advanced Auto because they could get me a unit in 3 hours vs. 1 day - so no preference there...


It works fine, but what I did find interesting was the brand Hamburg-Technic www.hamburgtechnic.com - never heard of them before, and my brother who has been in aftermarket parts for 20 years has not either... maybe new?

Also curious to see what the Autozone part is.


Here is a pic, notice the glue and rust that is around the main portion of the coil pack (below the chrome gard)?

[Joesturbo]

oh ya - here is the post but no one replied... http://www.audizine.com/forum/showthread.php?t=219094

[speedee911]

Why do people die?

Just accept the fact that they do (can be applied to both people and coilpacks).

of course, i understand that.. but i was asking because they all (or three of them) failed in quick succession and i was wondering if i did something wrong.. if someone you know dies you say this is the cycle of life, but when three people you know die in a week you ask yourself, am I next??

[fbottone]

Since replaced all with STI coils and been running like a champ! And nearly 150,000 km on the clock!

STI coils? Please elaborate...

[gtimart]

I was also thinking about the plug gaps recently. If the gap is bigger, it's tougher for the current to bridge it. Could that add stress to the coils ? When plugs use up, the gaps get bigger. If you don't replace the plugs, don't coils take the toll ?
By the way, coil pack failure is not just for Audis. My 2005 Impreza had the same issue.
Why does Audi put the coils in the engine, where it's the hottest ? Doesn't a single coilpack solution + plug wires fare better against heat ?

[MikTip]

From what Bremi(OE manufacturer of VW/Audi coils) hinted at, their coils were made in Belgium, and it was a quality control issue.... Bremi would not elaborate any further....

I'm sure there's billionss of dollars(Euro's) at stake here, being the supplier to Alfa Romeo - Audi - Autobianchi - Bentley - BMW - Chrysler - CITROËN - Bugatti - Daewoo - Daihatsu - Fiat - Ford - Holden - Honda - Hyundai - Isuzu - Kia - Lada - Lamborghini - Lancia - Landrover - Lexus - Mazda - Mercedes - Mitsubishi - Nissan - Opel - Peugeot - Porsche - Renault - Rover - Rolls-Royce - Saab - Seat - Skoda - Subaru - Vauxhall - Volvo - VW, for every coil-pack in nearly every vehicle they make!


http://www.en.bremi.de/b

[AudiA4Turbo22]

check ur engine wirring harness mine was lunch in a few places and they kept burning out on a weekly basis, and well i fixed it and changed them out and wallah!

[MikTip]

Here's a picture of some STI coils-



Cant say for certain if they fit and function on an Audi....

[AudiA4Turbo22]

^^actually STI is a German company that makes factory reproduction parts and i have a set, and they work fine!

[diagnosticator]

why do they fail? and is it normal for them to go all at once? three of mine failed in the last week.. is there something i can do to prevent future failures?

Basically, the internal components are not able to withstand the stresses experienced during operation. It's a design related weakness as well as a material quality issue. The most frequent cause provoking failure, is chipping the ECU. Most (but not all,) coilpacks fail soon after chipping, but some stock engines have had coilpacks fail also.
The chipped ECU tuning software, uses mainly increased boost for the performance increase. When boost is raised, the dynamic compression pressure in the cylinders at the ignition point, or position of the crank/piston when the spark needs to jump the plug gap, is a lot higher than it is stock. The higher dynamic compression pressure increases the voltage needed to force a spark to jump the plug gap. Until a spark jumps the gap, the secondary voltage of the ignition coil increases until the voltage is high enough to overcome the higher resistance of the denser compressed cylinder charge air. (Or, the insulation break down resistance value is exceeded, whichever condition occurs first.) The required voltage varies with throttle angle and boost if present, and is directly related to cylinder pressure at the ignition point.
Sooner or later, the "break down voltage" of the coilpack's primary output electronics or secondary coil winding insulation is reached due to higher voltage induced stresses on the insulation of the internal parts, or the ability of the output drive electronics to control the primary coil current, is exceeded. When this limit is reached, the coilpack cannot deliver the high voltage required at the plug gap, so misfires occur. The relationship between throttle valve angle, resulting cylinder compression pressure and the required ignition voltage, is why the symptoms associated with ignition misfire are typically worse with larger throttle opening angles when coilpacks fail.
BTW, it's almost impossible for two or more coilpacks to fail simultaneously. But they can and do fail randomly once the conditions associated with pending failure exist. The latest version "R" coilpacks are much more durable and reliable parts. (In)Practical failure prevention would involve fitting high end ignition coils with higher secondary output voltage capabilities compared to stock coilpacks. Capisce?

[diagnosticator]

I was also thinking about the plug gaps recently. If the gap is bigger, it's tougher for the current to bridge it. Could that add stress to the coils ? When plugs use up, the gaps get bigger. If you don't replace the plugs, don't coils take the toll ?
By the way, coil pack failure is not just for Audis. My 2005 Impreza had the same issue.
Why does Audi put the coils in the engine, where it's the hottest ? Doesn't a single coilpack solution + plug wires fare better against heat ?

The benefit of direct coil on plug designs, is that the high voltage output of the coil is fed directly to the spark plug. Designs using distribution wires, will experience trouble eventually due to material aging in the ignition wires and leakage of high voltage from the wires. With coilpacks or Coil On Plug direct ignition setups, the heat of the engine is not an issue provided the coilpack parts are made with the required heat resistant materials.

[thechan]

so what happens when they do fail?
what kind of impact does it have on your car?

[dougyfresh]

Basically, the internal components are not able to withstand the stresses experienced during operation. It's a design related weakness as well as a material quality issue. The most frequent cause provoking failure, is chipping the ECU. Most (but not all,) coilpacks fail soon after chipping, but some stock engines have had coilpacks fail also.
The chipped ECU tuning software, uses mainly increased boost for the performance increase. When boost is raised, the dynamic compression pressure in the cylinders at the ignition point, or position of the crank/piston when the spark needs to jump the plug gap, is a lot higher than it is stock. The higher dynamic compression pressure increases the voltage needed to force a spark to jump the plug gap. Until a spark jumps the gap, the secondary voltage of the ignition coil increases until the voltage is high enough to overcome the higher resistance of the denser compressed cylinder charge air. (Or, the insulation break down resistance value is exceeded, whichever condition occurs first.) The required voltage varies with throttle angle and boost if present, and is directly related to cylinder pressure at the ignition point.
Sooner or later, the "break down voltage" of the coilpack's primary output electronics or secondary coil winding insulation is reached due to higher voltage induced stresses on the insulation of the internal parts, or the ability of the output drive electronics to control the primary coil current, is exceeded. When this limit is reached, the coilpack cannot deliver the high voltage required at the plug gap, so misfires occur. The relationship between throttle valve angle, resulting cylinder compression pressure and the required ignition voltage, is why the symptoms associated with ignition misfire are typically worse with larger throttle opening angles when coilpacks fail.
BTW, it's almost impossible for two or more coilpacks to fail simultaneously. But they can and do fail randomly once the conditions associated with pending failure exist. The latest version "R" coilpacks are much more durable and reliable parts. (In)Practical failure prevention would involve fitting high end ignition coils with higher secondary output voltage capabilities compared to stock coilpacks. Capisce?

Great Response! Makes perfect sense to me. I failed my coil packs with OEM tuning. The 'R' coil packs are working just fine with my BT set-up.

so what happens when they do fail?
what kind of impact does it have on your car?

The ECU is smart enough to recognize this and will go into 'safe' mode and your CEL will go on. All turbo boost is bypassed (ie: waste gate is open 100%). The car runs very rough. It is advisable to drive only what is necessary (to the store for new coil packs primarily).

[A4ringedONE8T]

One would think the aerospace industry is better given strict requirements and regulations. Well, scrap rates for non-conforming parts are excessively high. Good news is the manufacturers scrap the parts before they get out into the field. Well, 99.9% of the parts....

This is why I hate airplanes, thanks for making me even more nervous. Ill take a failed automobile part anyday

[A4ringedONE8T]

Basically, the internal components are not able to withstand the stresses experienced during operation. It's a design related weakness as well as a material quality issue. The most frequent cause provoking failure, is chipping the ECU. Most (but not all,) coilpacks fail soon after chipping, but some stock engines have had coilpacks fail also.
The chipped ECU tuning software, uses mainly increased boost for the performance increase. When boost is raised, the dynamic compression pressure in the cylinders at the ignition point, or position of the crank/piston when the spark needs to jump the plug gap, is a lot higher than it is stock. The higher dynamic compression pressure increases the voltage needed to force a spark to jump the plug gap. Until a spark jumps the gap, the secondary voltage of the ignition coil increases until the voltage is high enough to overcome the higher resistance of the denser compressed cylinder charge air. (Or, the insulation break down resistance value is exceeded, whichever condition occurs first.) The required voltage varies with throttle angle and boost if present, and is directly related to cylinder pressure at the ignition point.
Sooner or later, the "break down voltage" of the coilpack's primary output electronics or secondary coil winding insulation is reached due to higher voltage induced stresses on the insulation of the internal parts, or the ability of the output drive electronics to control the primary coil current, is exceeded. When this limit is reached, the coilpack cannot deliver the high voltage required at the plug gap, so misfires occur. The relationship between throttle valve angle, resulting cylinder compression pressure and the required ignition voltage, is why the symptoms associated with ignition misfire are typically worse with larger throttle opening angles when coilpacks fail.
BTW, it's almost impossible for two or more coilpacks to fail simultaneously. But they can and do fail randomly once the conditions associated with pending failure exist. The latest version "R" coilpacks are much more durable and reliable parts. (In)Practical failure prevention would involve fitting high end ignition coils with higher secondary output voltage capabilities compared to stock coilpacks. Capisce?

Did you type that out of a book, copy/paste, or write from your mind/memory? If the last, holy shit!

[dougyfresh]

This is why I hate airplanes, thanks for making me even more nervous. Ill take a failed automobile part anyday

Its still safer than anything. Like I said, you should see how many parts we scrap due to the smallest non-conformances. It'll blow your mind. Those non-conformances will go unnoticed in the automobile industry yet are a show-stopper in the aerospace industry.

The problem us, as consumers, face is the decreasing profit margins of the public airline companies. Its becoming more and more costly to run an airline and thus they choose to cut corners. The FAA is slow in reacting therefore you run into issues like what some of the major airlines are faced with right now. To maximize profits they are also cutting flights which makes availability more and more difficult for us, the end users. Lack of flights and and increase in delays creates frustrations for the end users like you and I.

I can vouch from a propulsion standpoint (ie: engines) we are not cutting any corners and still doing things to strict requirements. I can not vouch for other companies though.

/end threadjack

[gtimart]

diagnosticator, thanks for the excellent response as always. I guess big plug gaps can also lead to premature coil failure as that also adds resistance.

[B6 Dude]

From an electronics perspective, I'll confirm that heat takes a serious toll on electonic components, and thermal cycling (cooling then heating then cooling etc.) makes it worse. The heat comes from both the outside (engine) and the inside (the electronics generate heat). The black epoxy filler you typically see on these parts is a thermal insulator (and moisture insulator) for this purpose, but running the car harder makes for more internally-generated heat.

What I wonder though is why don't they put proper heatsinks on these coils? I see some fins on the coils, but I heard that the B6's have the amps built into these coils, so I'd think it would need much more heatsinking. The B5 had the ignition amps in a separate housing, which was heatsinked (heatsunk?) and cooled in the airbox.

BTW, aircraft, even the small ones, take care of the problem with redundancy.

[F16HTON]

Basically, the internal components are not able to withstand the stresses experienced during operation. It's a design related weakness as well as a material quality issue. The most frequent cause provoking failure, is chipping the ECU. Most (but not all,) coilpacks fail soon after chipping, but some stock engines have had coilpacks fail also.
The chipped ECU tuning software, uses mainly increased boost for the performance increase. When boost is raised, the dynamic compression pressure in the cylinders at the ignition point, or position of the crank/piston when the spark needs to jump the plug gap, is a lot higher than it is stock. The higher dynamic compression pressure increases the voltage needed to force a spark to jump the plug gap. Until a spark jumps the gap, the secondary voltage of the ignition coil increases until the voltage is high enough to overcome the higher resistance of the denser compressed cylinder charge air. (Or, the insulation break down resistance value is exceeded, whichever condition occurs first.) The required voltage varies with throttle angle and boost if present, and is directly related to cylinder pressure at the ignition point.
Sooner or later, the "break down voltage" of the coilpack's primary output electronics or secondary coil winding insulation is reached due to higher voltage induced stresses on the insulation of the internal parts, or the ability of the output drive electronics to control the primary coil current, is exceeded. When this limit is reached, the coilpack cannot deliver the high voltage required at the plug gap, so misfires occur. The relationship between throttle valve angle, resulting cylinder compression pressure and the required ignition voltage, is why the symptoms associated with ignition misfire are typically worse with larger throttle opening angles when coilpacks fail.
BTW, it's almost impossible for two or more coilpacks to fail simultaneously. But they can and do fail randomly once the conditions associated with pending failure exist. The latest version "R" coilpacks are much more durable and reliable parts. (In)Practical failure prevention would involve fitting high end ignition coils with higher secondary output voltage capabilities compared to stock coilpacks. Capisce?

Bullshit answer with far to many words.

The coilpacks fail because there is a shitload of energy going through them and the only thing that seperates it from the path of least resistance is the insulator between the electrode and the head.

Unfortunately the insulator cracks, the reason most coilpacks go out after chipping is because every single software company recommends that you go with a plug that has on heat range colder. So what do we do? We change the plugs...in order to do this we remove the coilpacks and crack the insuating material when we do.

There is an actual coilpack removal tool the dealers and high quality shops have.

There is a design flaw in the coilpack, this has been proven by the fact that VAG and their suppliers are constantly revsing them to make them better...

[PRY4SNO]

STI coils? Please elaborate...

Subaru Technica International... no I'm kidding.

It stands for Spark Transfer International. I actually didn't want this brand, but after I'd chipped my car and promptly blew a CP my tech provided a Bremi brand replacement. When I got home the week following after my ensuing mountain road-trip/test I blew another. So I ordered one from the Lexus dealership I was working at and even though the manifest said Bremi, the STI brand came in. So I ordered another three just because I'm OCD that way. Nice to have spares, too... just in case.

But they work great so far, no special tools used to replace plugs at oil changes and no problems... 20,000 km and counting.

[PRY4SNO]

Bullshit answer with far to [sic] many words.

The coilpacks fail because there is a shitload of energy going through them and the only thing that seperates [sic] it from the path of least resistance is the insulator between the electrode and the head.

Unfortunately the insulator cracks, the reason most coilpacks go out after chipping is because every single software company recommends that you go with a plug that has on heat range colder. So what do we do? We change the plugs...in order to do this we remove the coilpacks and crack the insuating [sic] material when we do.

There is an actual coilpack removal tool the dealers and high quality shops have.

There is a design flaw in the coilpack, this has been proven by the fact that VAG and their suppliers are constantly revsing [sic] them to make them better...

Not to start a flame war... I do respect your contribution to the communities and vast experience. Seriously.

But perhaps for some of us, yours was the bullshit answer... one with too many gross generalizations intended for a non-technically inclined audience. (I myself read the Globe & Mail or Wall Street Journal... not the Sun or the NYPost/USA Today.) A technical answer has all the details and I can choose for myself what to filter out, which is immeasurably better.

I know of at least three techs (two of whom own their own shops) who never use a CP removal tool on their personal cars yet have no issues with VAG coils, modified or not. Talk about rolling the dice.

And John's answers are NEVER BULLSHIT . I learned that the hard way, costing me thousands because I didn't heed his advice. JMO, though... take it or leave it.

[BARRY]

400hpa4...

i'm sorry but your answer was absurd.

[diagnosticator]

Did you type that out of a book, copy/paste, or write from your mind/memory? If the last, holy shit!

I typed/composed just for this reply, from memory. Sometimes my replies are a bit long, but in order for the information to make sence, background is needed also.