Should coil packs be scheduled for replacement?
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Coil on my Corolla went bad on 240k, and 190k on my Integra. It is really hard to tell when would they go bad but I don't think they are "fatal" like interference engine timing belt.
Originally Posted by ragtoplvr
in my opinion, if you as a manufacturer routinely find it impossible to design and specify a coil pack that will last the life of the vehicle (or at least 200K miles) with a less than .1% failure rate then you are a total failure. The executive management needs fired, and the purchasing, engineering and testing departments need evaluated and the non-performing persons need fired. I will not be your customer unless you step up and pay for the repairs.
This is why I have my last BMW.
Rod
If those are your criteria for buying a new car...
I think your next car should be a bicycle.
in my opinion, if you as a manufacturer routinely find it impossible to design and specify a coil pack that will last the life of the vehicle (or at least 200K miles) with a less than .1% failure rate then you are a total failure. The executive management needs fired, and the purchasing, engineering and testing departments need evaluated and the non-performing persons need fired. I will not be your customer unless you step up and pay for the repairs.
This is why I have my last BMW.
Rod
If those are your criteria for buying a new car...
I think your next car should be a bicycle.
Nick1994
$100 site donor 2024
Originally Posted by rooflessVW
Originally Posted by ragtoplvr
in my opinion, if you as a manufacturer routinely find it impossible to design and specify a coil pack that will last the life of the vehicle (or at least 200K miles) with a less than .1% failure rate then you are a total failure. The executive management needs fired, and the purchasing, engineering and testing departments need evaluated and the non-performing persons need fired. I will not be your customer unless you step up and pay for the repairs.
This is why I have my last BMW.
Rod
If those are your criteria for buying a new car...
I think your next car should be a bicycle.
I agree. If a coil went bad on my Sonata, I'd shrug it off and throw a new $50 coil on it. Not a big deal.
Originally Posted by ragtoplvr
in my opinion, if you as a manufacturer routinely find it impossible to design and specify a coil pack that will last the life of the vehicle (or at least 200K miles) with a less than .1% failure rate then you are a total failure. The executive management needs fired, and the purchasing, engineering and testing departments need evaluated and the non-performing persons need fired. I will not be your customer unless you step up and pay for the repairs.
This is why I have my last BMW.
Rod
If those are your criteria for buying a new car...
I think your next car should be a bicycle.
I agree. If a coil went bad on my Sonata, I'd shrug it off and throw a new $50 coil on it. Not a big deal.
Its hard to avoid a knee jerk reaction, this is a difficult question. If a coil fails and you can get at the injector plug then its easy enough to unplug it and continue until you get the new coil.
On the other hand if you cant you have a real problem, the cat could be damaged in short order. On many of the cars and bikes I have owned coil failure is very common so yes I changed them at about 90-100K. Honestly when I think about the amount of work the coil(s) perform every minute and the fact they and the materials they are made from weaken with heat and age I wouldn't knock someone for swapping them out.
I do change the front O2 sensor at about 100K or a little sooner if its a bad one(s) to get at and the opportunity presents itself while doing another job.
On the other hand if you cant you have a real problem, the cat could be damaged in short order. On many of the cars and bikes I have owned coil failure is very common so yes I changed them at about 90-100K. Honestly when I think about the amount of work the coil(s) perform every minute and the fact they and the materials they are made from weaken with heat and age I wouldn't knock someone for swapping them out.
I do change the front O2 sensor at about 100K or a little sooner if its a bad one(s) to get at and the opportunity presents itself while doing another job.
I carry a spare with me.
My experience is not the same as some others here where the PCM detects and throws a code for a bad coil pack. I dont remember the last time that happened. It just doesnt happen unless the coil is unplugged or straight dead. Meanwhile everytime I ease into the throttle above steady state cruise I can feel the engine stuttering. So, I also have a OBDLink MX to pull Mode 6 data and see which cylinder has the highest misfire counts.
Previously I would move a new coil pack from cylinder to cylinder until the miss went away. Would take a long time to cycle it through all 8 cylinders and find which one fixes it.
I did notice they were becoming frequent on my 02 with 200k miles, so I think thats probably around the right time for that.
My experience is not the same as some others here where the PCM detects and throws a code for a bad coil pack. I dont remember the last time that happened. It just doesnt happen unless the coil is unplugged or straight dead. Meanwhile everytime I ease into the throttle above steady state cruise I can feel the engine stuttering. So, I also have a OBDLink MX to pull Mode 6 data and see which cylinder has the highest misfire counts.
Previously I would move a new coil pack from cylinder to cylinder until the miss went away. Would take a long time to cycle it through all 8 cylinders and find which one fixes it.
I did notice they were becoming frequent on my 02 with 200k miles, so I think thats probably around the right time for that.
Ummm ...keep in mind before replacing a coil that the problem can be more than just a bad coil. The very hi voltages require that Dielectric grease be applied to the boots as they are pushed on. Dont be stingy with that stuff!!!. It fills the voids like electrical tape and denies contaminants entry. If you're an engine washer clean freak you can get misfires from water getting near the boots and contaminating the Dielectric ...and guess what contamination is conductive. Once you get a few arcs going the carbon tracks created across the boot and the condition becomes permanent. Even if you are normal and don't spray wash your engine that dieelectric grease can dry out and be less effective. Check the coils with ohm meter and if within spec reapply dielectric and put em back in.
Fight the urge to spray wash your engine...
Fight the urge to spray wash your engine...
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In our GM fleet trucks the coils last about as long as a good iridium plug does. That has been over 250k miles in real world service, but not regularly. I've always felt the wires and plugs were a great influence on a coils lifespan.
I think the problem with modern coils is their size. In the old days the coil had a thick hard plastic case that was molded onto the coil wiring itself. Bulletproof physically and nearly bulletproof electrically except at the tower if contaminated would track. In most cases you could sand away the carbon track and lacquer the crack and have basically a rebuilt coil. Nowadays the coil on plugs are really tiny with no real physical space electrically and little mechanical resistance. I've had to change them on VW gassers but never so far on any of the Mopar stuff. The Mopar coils are much larger than the VW coils and that may have something to do with it.
Going back coils were oil filled, GM vertically mounted them on a slight angle but Ford mounted them horizontal and this made a difference, the horizontally mounted ones sometimes leaked and overheated causing all sorts of gremlins.
Also, look at the boots:
https://forum.ih8mud.com/threads/ignition-coil-boots-maintenance.1024086/#post-11327885
https://forum.ih8mud.com/threads/ignition-coil-boots-maintenance.1024086/#post-11327885
BMW doesn't have a 100K replacement recommendation, at least not in general.
BMW (Bremi and Bosch) coils typically last the life of the engine. I frequently see cars in the boneyard with a matching set of old date codes. My cars (100K, 250K and 340K miles) all have the factory sets.
Replacement coils, on the other hand, have a reputation for failing after a few years.
The connectors ("boots") do have a shorter lifetime and occasionally need to be replaced, especially if they have spent a few years soaked in oil. I suspect most coil replacements are due to failed connectors.
Of course there are always the bad batches, like a specific type installed in 2003-2005. But a bad batch is different than not being able to make reliable ones at all.
BMW (Bremi and Bosch) coils typically last the life of the engine. I frequently see cars in the boneyard with a matching set of old date codes. My cars (100K, 250K and 340K miles) all have the factory sets.
Replacement coils, on the other hand, have a reputation for failing after a few years.
The connectors ("boots") do have a shorter lifetime and occasionally need to be replaced, especially if they have spent a few years soaked in oil. I suspect most coil replacements are due to failed connectors.
Of course there are always the bad batches, like a specific type installed in 2003-2005. But a bad batch is different than not being able to make reliable ones at all.
The 2AZFE in my Camry ate coils. I just kept a spare in the trunk along with a 10mm wrench.
It would actually run bad for a while before popping a code. If I was off the gas (stick shift) and then got back on it there was a lag, almost like I had a tire on ice.
The factory Densos were long gone by the time I got it at 200k but I noticed no quality difference between various cheapo replacements. BTW if the Densos were that great they'd still be on the car, right?
It would actually run bad for a while before popping a code. If I was off the gas (stick shift) and then got back on it there was a lag, almost like I had a tire on ice.
The factory Densos were long gone by the time I got it at 200k but I noticed no quality difference between various cheapo replacements. BTW if the Densos were that great they'd still be on the car, right?
Originally Posted by Kawiguy454
Ummm ...keep in mind before replacing a coil that the problem can be more than just a bad coil. The very hi voltages require that Dielectric grease be applied to the boots as they are pushed on. Dont be stingy with that stuff!!!. It fills the voids like electrical tape and denies contaminants entry. If you're an engine washer clean freak you can get misfires from water getting near the boots and contaminating the Dielectric ...and guess what contamination is conductive. Once you get a few arcs going the carbon tracks created across the boot and the condition becomes permanent. Even if you are normal and don't spray wash your engine that dieelectric grease can dry out and be less effective. Check the coils with ohm meter and if within spec reapply dielectric and put em back in.
Fight the urge to spray wash your engine...
I never use dielectric. Its only to make it easier to remove the boots after a few years. You dont want it so packed in there the coil doesnt make contact with the plug. Being that its dielectric and not conductive that can be a problem. If you're gonna use it, use a brush to wipe some onto the spark plug. Dont pack the coil boot with dielectric, thats not the proper way to use it.
Ummm ...keep in mind before replacing a coil that the problem can be more than just a bad coil. The very hi voltages require that Dielectric grease be applied to the boots as they are pushed on. Dont be stingy with that stuff!!!. It fills the voids like electrical tape and denies contaminants entry. If you're an engine washer clean freak you can get misfires from water getting near the boots and contaminating the Dielectric ...and guess what contamination is conductive. Once you get a few arcs going the carbon tracks created across the boot and the condition becomes permanent. Even if you are normal and don't spray wash your engine that dieelectric grease can dry out and be less effective. Check the coils with ohm meter and if within spec reapply dielectric and put em back in.
Fight the urge to spray wash your engine...
I never use dielectric. Its only to make it easier to remove the boots after a few years. You dont want it so packed in there the coil doesnt make contact with the plug. Being that its dielectric and not conductive that can be a problem. If you're gonna use it, use a brush to wipe some onto the spark plug. Dont pack the coil boot with dielectric, thats not the proper way to use it.
Originally Posted by StevieC
Nope... When they generate a code. Even a slight misfire will trigger a check engine light. My dad's 2012 Caravan has coil overs on his Pentastar V6 and they are original at 300K
I am in the same boat. 241k miles and no change in coils. From what I've heard is that keeping good plugs in does save the coils.
Nope... When they generate a code. Even a slight misfire will trigger a check engine light. My dad's 2012 Caravan has coil overs on his Pentastar V6 and they are original at 300K
I am in the same boat. 241k miles and no change in coils. From what I've heard is that keeping good plugs in does save the coils.
I do change my plugs early. My new Highlander calls for plug replacement at 192,000km Yeah they are getting done at 100,000. PERIOD. And using exactly the type that came out. Which are the Iridium Denso with the 3 grounds.
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OEM coils that come new on the vehicle have a great reliability, that wouldn't necessarily be true even if you got OEM coils.
If the vehicle calls for replacing new plugs at a specific interval, they if one has the money why not change the coils as well.
Coils fail randomly in warranty and out of warranty and they don't fail at all for some reason (the lucky ones).
If the vehicle calls for replacing new plugs at a specific interval, they if one has the money why not change the coils as well.
Coils fail randomly in warranty and out of warranty and they don't fail at all for some reason (the lucky ones).
I must be super lucky. I've never had a coil fail. Even on the old saturns i have had. I do use dielectric grease. I also slightly undergap my spark plugs when i install. That is an old carry over from the old days to account for wear. I have a round type wire gapper. If the spec is say .045. I'd gap so the .045 did not fit, but the .040 was clear with no drag at all. I especially did that on the engines that spec'd an .060 gap.
I wonder if the slightly smaller gaps were easier on the coils.
I wonder if the slightly smaller gaps were easier on the coils.
Originally Posted by spasm3
I wonder if the slightly smaller gaps were easier on the coils.
For sure it is. A wider gap gives a smoother idle but puts more stress on the coil. When I was in school back in the points, condenser, rotor days they demonstrated the effects of plug gap, first a smaller gap then a wider gap to show the effects.
These were larger differences not just a couple of thou. the closer gap ran a little rougher and the wider much smoother but anymore it would misfire.
Modern coils produce much more energy than the old ones so wider gaps without misfire as the age are possible but it does stress the coils.
Ignition coils generally fail due to heat either generated internally from poor mechanical connection, shorts or loss of cooling oil in the case of old style coils or external due to their position on the engine, cracks or damage to the housing will also cause the coil to act up
There is no actual mechanical failure, static wire doesn't wear out but the insulation can be damaged by over stressing the coil causing internal temperature increase.
Some coil units like the 4 post coil packs, waste spark coils and some COP units fail early and regularly due to heat breaking the winding insulation down, if you have a car that is known for this its prudent to swap them out before they act up or fail. Others seemingly go on forever.
the best thing is to inspect them when doing a service, if it has cracked or burned boots in the case of COP coils there is a good chance it could fail sooner than later. Any coil with a crack or burn marks should be changed.
These will tell you almost everything you wanted to know about coils.
https://www.hella.com/techworld/uk/Technical/Car-electronics-and-electrics/Ignition-coil-2886/
https://www.autoserviceprofessional...ils-What-every-tech-needs-to-know?Page=1
I wonder if the slightly smaller gaps were easier on the coils.
For sure it is. A wider gap gives a smoother idle but puts more stress on the coil. When I was in school back in the points, condenser, rotor days they demonstrated the effects of plug gap, first a smaller gap then a wider gap to show the effects.
These were larger differences not just a couple of thou. the closer gap ran a little rougher and the wider much smoother but anymore it would misfire.
Modern coils produce much more energy than the old ones so wider gaps without misfire as the age are possible but it does stress the coils.
Ignition coils generally fail due to heat either generated internally from poor mechanical connection, shorts or loss of cooling oil in the case of old style coils or external due to their position on the engine, cracks or damage to the housing will also cause the coil to act up
There is no actual mechanical failure, static wire doesn't wear out but the insulation can be damaged by over stressing the coil causing internal temperature increase.
Some coil units like the 4 post coil packs, waste spark coils and some COP units fail early and regularly due to heat breaking the winding insulation down, if you have a car that is known for this its prudent to swap them out before they act up or fail. Others seemingly go on forever.
the best thing is to inspect them when doing a service, if it has cracked or burned boots in the case of COP coils there is a good chance it could fail sooner than later. Any coil with a crack or burn marks should be changed.
These will tell you almost everything you wanted to know about coils.
https://www.hella.com/techworld/uk/Technical/Car-electronics-and-electrics/Ignition-coil-2886/
https://www.autoserviceprofessional...ils-What-every-tech-needs-to-know?Page=1
I'm in the "change them when they have a problem" camp.
On engines like the old 4.6L Modular, access is easy enough that I do them as they fail. On other vehicles where access is poor, I usually do them all when one goes.
Someone commented on them not lasting as long as old single coils. I suspect part of that is due to them being "buried" in the engine where they are subject to higher temperatures and more vibration as compared to having them mounted on the fender or wherever. With that said, failure of a single coil system can be aggravating because it's the last part you suspect in the ignition system(maybe second to last after the condenser, although in my little corner of the old car world condensers went from being effectively a lifetime part to a "carry a spare with you" part thanks to poor quality and questionable construction). The one coil failure I had was a bit baffling as it was sparking out of the coil but I suspect was weak enough that it was getting "lost" in the distributor or wires. I actually had a complete spare ignition system in the car(distributor, cap, rotor, and wires) and had to conclude it was the coil after changing out every other part. On testing, the 3Ω(rated) coil was 4.5Ω...
On engines like the old 4.6L Modular, access is easy enough that I do them as they fail. On other vehicles where access is poor, I usually do them all when one goes.
Someone commented on them not lasting as long as old single coils. I suspect part of that is due to them being "buried" in the engine where they are subject to higher temperatures and more vibration as compared to having them mounted on the fender or wherever. With that said, failure of a single coil system can be aggravating because it's the last part you suspect in the ignition system(maybe second to last after the condenser, although in my little corner of the old car world condensers went from being effectively a lifetime part to a "carry a spare with you" part thanks to poor quality and questionable construction). The one coil failure I had was a bit baffling as it was sparking out of the coil but I suspect was weak enough that it was getting "lost" in the distributor or wires. I actually had a complete spare ignition system in the car(distributor, cap, rotor, and wires) and had to conclude it was the coil after changing out every other part. On testing, the 3Ω(rated) coil was 4.5Ω...
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