Could someone please explain how a coil can wear out?
Setting aside physical damage (cracks, etc.).

There are lots of folks saying that coil packs get weak or worn out, how does this happen?

Are there resistors or capacitors that change value over time?

What are these packs circuit design?
One can't tell as they are potted in epoxy and can't be opened for inspection or component measurement.

Its not rocket science, coils are one of the most basic circuits in electricity.

 

Mike?

 

Well, understand that this is just speculation, but I just changed mine on my '97 4.6l with 135,000 miles on it. Never been changed, and took about 15 min per bank.

The reason I changed them was the lousy gas milkeage I was getting and I figured it couldn't hurt toi put on Accels from Mike Troyer.

Best mileage I could get was 12-13 before the change. After doing the coils and a double treatment of Seafoam, I seem to have picked up about 2 mpg; avg 15.5 the last couple tankfulls.

 

It seems that your gains could be attributed to many factors, the decarbonisation, gas changing over from winter formulations, your superchip tune enjoying the warmer weather, etc...

You really didn't answer my question, which is:

How do coil packs get worn out?

There are vendors here pimping coil pack replacements with the implication that the OEM packs get weak and worn out, so I would think that there is some evidence to support his claim.

I have searched here, in other forums, on the internot and cannot find any evidence other than anecdotal claims such as the one that has been made in the post before this one.
As a matter of fact there are many sites that state that coil packs wearing out is a myth.

Is there an explanation to support the 'worn out' claim?

 

loudest

I'm no expert, but if I were to venture an opinion on "how coil packs wear out", I would offer this. It would seem too me that they would have to degrade over time simply from the harsh environment they are subjected to. I am thinking of first the under hood temperatures meaning the heat soak coming off the engine and/or from the radiator. Second, I am thinking of the 1,000s of volts the coils are producing must degrade the coil over time.

Of course playing Devil's advocate against my own arguement I then ask myself, "how much can a coil degrade before it should be replaced?" I don't know. I imagine coils would last many thousands of miles before they actually totally failed and tripped a cel.

The real trouble here, in my opinion, most lay folks aren't going to do sophisticated testing on their own coils or plug wires, then buy new ones, install them, and then conduct more testing just to see if new coils installed at 40,000 miles makes a difference--
a difference in mpg or horsepower.

In sum I believe we almost have to trust the vendor in which we are doing business, that they have done the testing for us and know what parts are worth replacing and what is simply 'banging the cash register'. Most vendors don't do any testing and simply resell anything that will turn a profit.

In my personal case I replaced my coil packs at 40,000 miles with MSD parts and noticed a smoothing out of idle and engine sound in general. I believe throttle response improved, but this certainly wasn't any huge change like spraying NOS, for instance.


ENB

 

ENB

There are Tesla coils built by Tesla himself that are still functioning on a daily basis. His coils produced MAJOR voltage and sparks that are measued in feet.
The basic coil hardware is original, The only non original parts are things that do change values over time (like condensers for instance).
This is why I asked if there are capacitors or resistors in those epoxy potted packs.

You experienced a difference when you upgraded to MSD coils which is typical because they produce more energy and possibly recover faster at higher rpm's (I am guessing) but one doesn't get that for free... the higher the spark energy means the shorter the life of the electrodes of the sparkplugs.

The difference wasn't worn out coils, it was a hotter coil replacement.

So far no one has explained how or why coils get weak or tired yet will tell you to get a new set based on that information.

 

Hello loudist,

This is way off topic for the Computer Chips section, I'm afraid................................

When we have the time, after taking care of our paying customers, the people that actually keep us in business - *then* I can think about trying to steal a few minutes to answer questions that are appropriate/related to the topic of this section - that's about as far as it goes here, my friend.

I agree, you raise an interesting question as to the actual deterioration of coil packs - and in our experience it varies - from one batch to the next sometimes, as well as based on what year of vehicle, the actual style of ignition coil, etc.

I really am not qualified to argue Tesla's work - but I do not believe one can use his work as "proof" that automotive ignition coils absolutely cannot and do not deteriorate - what we have seen does not bear that out.

Ever tried doing any hands-on measuring/testing of the actual output of these coil packs brand new (which isn't "good" to begin with), and then again after say, 3-4 years and 50K or 70K miles? Ever tested their saturation times/capability when brand new and again after some time/miles, etc?

We've done a bit of that over the years in our work with various ignition manufacturers, and I'd be the first to say that this is one area where I'd like to be able to spend a *lot* more time and R&D. In fact, it looks like we're going to be releasing a new COP ignition upgrade in the next few months (though it's going to be expensive, something really only appropriate for racers or those with $$$ to spare, etc.).

Automotive coil packs like modern FoMoCo units have to function in everything from 60 below 0 (F) to 220 above under the hood - dry to soaking wet, liquid to ice - constant shock & vibration any time the vehicle is being operated, with COP units mounted recessed in a well where they are constantly being "cooked," using raw materials sourced from the lowest bidder, being "pushed" by the PCM as the coil packs, plug wires & spark plugs on the older pre-COP ignitions age, etc. - especially the spark plug wires on the 1997-1999 4.6 F-150's, for example.
Their output and saturation times do not always remain a set constant over time. They vary - some deteriorate significantly while others deteriorate very little, just as you might imagine - and this is usually related to the coil design and it's direct proximity to heat (and just how much), vibration, contaminants, etc.

I replace the COP coil packs in my 2001 Lightning at least twice a year - and immediately see improved idle quality & throttle response as a result. Depending on how long I leave them in, we'll also see a bit more power & fuel mileage - some of the changes (particularly mpg when changing 4 month old coil packs) are small enough that it would really take truly repeatable lab conditions to identify/quantify properly.

Overall, with as long as most owners keep the stock ignition components in these Ford trucks & SUV's, there's easily enough difference there for us to see noticeable improvements in 1/4 mile times, throttle response & fuel mileage, for example, just from replacing the coil packs alone.

You might want to try talking with companies like MSD, Accel, etc. - the actual manufacturers of high-performance ignition components, and see what they have to say - assuming you can actually get a real engineer on the phone who is willing to take the time, and second, actually share some meaningful data - but it's worth a phone call just to get up to speed on their view of "the basics."

Good luck!

 

Yah, it might also cut into the time you spend spamming sales-pitches in this forum....

 

I can only give you a theory based on my electronics experience. I do not know for a fact that the windings in the coils get hot and short out but that is common problem with electrical devices with windings. If the coil insulation is a varnish type then extreme heat can case the insulation to melt and they begin to short out. You would see less resistance in the primary or secondary windings if this occurs which would result in less voltage or current produced for the spark. Another thing that happens in electrical components is that resistance can change when a component is heated but I do not think this applys to wire unless the diameter of the wire was reduced because of extreme heat.

I would be willing to say that the quality of manufacture would be different between 10 coils off the assembly line and only some of the coils would fail in extreme conditions because of this.

Food for thought.

Some of the insulation characteristics that are tested:

http://www.astm.org/cgi-bin/SoftCart...535+1085034230

 

Thanks to everyone who has posted on this.

I used the Tesla reference as an example of high energy discharge coils and the time mileage that has been seen as they are the oldest ones in existance.

I am suspect of anything that is potted in epoxy, as it serves to hide things, like the simplicity of the circuit, while making it impossible to correct a problem, like a pooped out capacitor (condensors in mechanical distributors).
This makes the end user have to buy a whole new pack for the 10 cent part that failed or went out of spec.

Griffin, yea Mike is a pimp and does bark his wares every chance he gets, but he does share knowledge while doing the pimping, so I guess it evens out in the end.
No insult intended BTW.

 

"Griffin, yea Mike is a pimp and does bark his wares every chance he gets, but he does share knowledge while doing the pimping, so I guess it evens out in the end.
No insult intended BTW."

Mike is one of the most respected posters on this board. He knows more about these trucks than most posters ever will. If, while imparting some of his vast knowledge, he chooses to remind people of the products and services he offers that makes him a good salesmen not a "pimp".

Calling someone a "pimp" is not the way to "win friends and influence people" here or anywhere else. Trying to cover with "No insult intended" just don't cut it.

 

Whatever... at the end of the day he is here pimping his wares.
Every answer turns into a product placement.
Coil packs every 4 mos?
Please spare me...

You are fireing on the exhaust stroke, perspectivewise...
I believe you have it backwards.... he is here to sell and wraps that in helpful opinion, not here to be the answerman with a little sales pitch thrown in...

Sorry, I don't kiss *** as well as you...
Or demigod a 'salesperson' on the internot.

 

Couldnt have said it better myself.

 

I took Mikes advice and called MSD ignition tech line.

They said that the coils for my truck (not COP) do not 'wear out' although they do not put out their full potential, which is 40,000 volts.
They said from day one of the engines life it was typically putting out 15k - 20k volts.
They also said changeing coil packs alone will not raise the voltage... one must install a driver amplifier for a hotter spark (which the original ford coil packs can handle up to 40k volts).

I would imagine the operating temps of the coil pack would go up significally with double the voltage output, so if there were a manufacturing or design weakness, it could show up and fail with the hotter driver amplifier.

 

Griffin (and others),

Mike is a Supporting Vendor and an advertiser here. That means he is one of the people that helps pay the bills and he has purchased the right to talk about his products on the forums. That also means that he is one of the people that enables you and others to utilize these message boards for free. If you have a problem with one of his posts, ignore it and move on.