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Multiple coil problems with 2011 Accent

22K views 43 replies 23 participants last post by  jkw017 
#1 ·
My 2011 Hyundai, at 34,000 mi., has had all 4 coils "go bad" one after the other over the past 12,000 miles. All coils were replaced under warranty at the Long Beach CA dealership. Now the first replaced coil has failed and the dealership says the only fix is to keep replacing them. Does anyone know if there is an underlying problem?
 
#4 ·
I've had the same problem - the coils went twice, and I'm taking it into the dealer tonight for what is probably the third time. First and second were at ~40k and 50k miles, now it has 61.5k. They blamed it on the plugs, but had new ones put in at 50k too. Did you find out what caused your problems?
 
#7 ·
I wonder how they break. Do they "burn out" like light bulbs all of a sudden or is it more progressive, and then past a certain point their activity isn't strong enough to do anything? If it is progressive maybe they can be periodically checked how hmaservice says to check them.
 
#8 ·
the coils are really just a transformer - converts current into voltage. you get low voltage and 'high' (ha) current coming in and then very low current and very high voltage coming out. the net energy has not changed minus a small amount lost due to the efficiency. its actually very very small.

so to answer the question of is it fast or not, it really depends on the failure. if insulation on the windings is breaking down, i'd imagine it would happen bit by bit until it his that complete failure point.

if you're getting moisture in there...well i think everyone can figure that one out.
 
#9 ·
my car run up to today 147K kilo and thanks that no problem in the coil...
but my friend called me up today, he said that his car had some misfires symptoms, i said to him to change the fuel filter(cause i change mine already when i have the same problem) but again he still have the same symptoms, let us try to change the coil or the SP wire...
 
#11 ·
I too have a 2011 accent and it has 54k miles on it. I am taking it in for the fourth time for the coils. They replaced three already all different ones. I said also while its in replace the last on too cause you know it will go bad. They would not do it because it didn't have a check engine light. Now of course the check eng lite on and I know its the last of the coil packs gone bad. What the **** I have a 2002 accent with 190k on it and no coils packs ever went bad... wats going on. I also don't like the fact that some posts say the replaced ones are going bad too.
 
#13 ·
Vendor issues with part longevity issues..

Another problem is hyundai dont pull all previous edition part off shelf, they sell them out until new parts falls in line to be shipped to dealer as dealer order.. but that should have went away a few yr back with all the misfire concern we have..


We have had pretty good luck here, dont seem to have repeat offenders here, just maybe 1 coil here, 2 coil there, another with one and so on.

Those that been show up with misfire DTC and run fine, other than MIL, usually get the PCM upgrade Hyundai put out for updating PCM to revise DTC logic for various codes, plus what ever else they slide in and not tell us about.
 
#14 ·
Other than manufacturing problems coils just don't 'go bad' by themselves for no reason. If you feel missfire problems investigate before more damage is done. Two most likely causes for missfire are bad plugs, excessive gaps, fouled electrodes, just worn out. Or moisture that has gotten down into the HV well around the plug. Both of these will be obvious if you spend 15 Minutes and take the plugs out, if there's rust, white oxide looking deposits or nasty gunky snot down there get out your bottle of we call it Methylated Spirits, I think it's wood alcohol (maybe IPA?) in the US and clean like no tomorrow. The alcohol won't hurt the coil so don't be shy, clean every crease and mould line that could be holding dirt. If the plugs have large amounts of deposits on them just ditch them and fit new correctly gapped plugs. I worked on large industrial gas engines (Jenbacher) these lean burn engines ran 25 - 35 KV firing voltages, it only takes a clumsy mechanic with an oily hand to ruin a $700 spark plug.
 
#15 ·
2011 accent. 32,000Km on it. Coil went bad, dealer replaced under warranty. They said expect another failure soon. "Known problem, they keep lots in stock".

Symptoms... misfire, no power, unburnt fuel into exhaust, smells bad. CEL on. I didn't have a code scanner at the time, I do now.
 
#18 ·
the coils are a well known problem with this particular car. would be good if someone were to take a dead one and try to figure out the root cause....if moisture is getting in this is something that could easily be fixed so that it doesn't happen again. or another thought, how different are coils off another car? ie. the LC accent which does not have this problem...wonder if they could be adapted to work? maybe i'll look up the specs once i get my computer back.

iridium does take less voltage to fire due to the much finer tip. problem is the cost...and i would be concerned that it would be a band-aid fix. replacing a faulty coil would make much more sense.

copper plugs can last longer than 30k :p clean with wire brush, regap and toss back in. i replace them when the electrode is going round and worn down to the nub.
 
#19 ·
Im getting ready to do 1st plug change at a little after 30k miles this weekend with the oem ngks and was wondering if any sort of mishandling of the coils during removal can cause this. I plan on just going by the hyundai maintenance website for procedure, but still makes me nervous since this part seems to cause a good amount of issues.
 
#20 ·
Be sure to twist them loose from the plug before pulling up on them. Your new plugs too should get a thin coating of silicone grease on the porcelain.

I had a Ford that the model had a history of bad coils. They would develop tiny cracks in the hard outer plastic. Seems the aftermarket coils were all OK but the OE ones were not.

I have had the coils off of my 2008 Accent 4 or 5 times and no problems. Seems to be a quality issue withe OE coils on the newer years?
 
#23 ·
I changed out the plugs 1st time yesterday and things went alright, hope I tightened them up right. Anyways, I put a little of the grease around the rubber lip that goes around outside on top of the coil, thought that seemed logical to keep moisture out. The original plugs were champion and had some whiteness to them (1st manual so there was some stalling and laboring the engine, dont know if that had anything to do with it). I put in ngks, car seems to run a little quieter at low rpms, everything else same. Hope the coils hold!
 
#24 ·
6 months on from my previous post in this thread, car started running rough and lost power. Trapped a p0302 error, misfire #2.

I tried cleaning the factory coil, no change. Swapped in a replacement, problem gone. Both new and old coil measured about 0.96 ohms. No apparent carbon tracks, cracks or anything.

I'll probably order up a spare for next time... I see rock has them for about $45.
 
#26 ·
I have an '08 - it's one coil per cylinder, likely the same in the '11.

My wife, bless her, had the car for 75K miles before we met and never had it tuned up. Car started misfiring and running like crap. Changed plugs (they were completely burned out), tried a few other things (cleaning throttle body, checking MAF sensor, etc), then discovered some info that indicated that not replacing plugs in a timely fashion can indeed cause the coils to fail - replaced the coils and the car runs great now.

Make sure you're tuning it up on time, is all I got to say...
 
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