Ignition Coil Symptoms, Problems, Diagnosis and Replacement – EASY DIY!


it wasn’t on everybody its carofoley
here with FCP euro and today I’m gonna take you through the steps on how to
easily diagnose a basic cylinder misfire due to initial coil we have a perfect
example right here so let’s get started now there’s two ways to identify a
cylinder misfire you can either use a scan tool which we’ll just call it the
high-tech easy method basically just plug the scan tool in and it will tell
you exactly where cylinder is dead option number two is you can actually
disconnect the initial coils in the engine bay this is the low-tech approach
no scandal required but we’re going to show you both ways of doing it just so
you don’t have a scan tool or you do have a scan tool you know both ways and
we’ll get started on that now so we do have a check engine light illuminated
you can also hear the car definitely is not idling very smoothly currently we’re
showing a cylinder one misfire detected so that is actually the fault that is
triggered cylinder one misfire detected pending cylinder one misfire detected
permanent so clearly something was going wrong in cylinder one what can cause a
misfire could be mission coil could be wiring leading to the ignition coil
could be a defective coil could be a bad spark plug or it could be something
mechanically wrong in the cylinder number one it could also be fuel
injector two what we want to do is eliminate any possibilities quickly
without really going too deep into it there is another way that you can do
this manually in order to determine the misfire if you don’t have a scan tool I’m gonna pop the engine cover up now I already know it’s cylinder 1
that’s the problem but you can actually disconnect individual coils now I’ve
disconnected cylinder number 1 and nothing has changed in terms of how the
engine is running if you’ve disconnected coil and nothing
changes that’s pretty much a dead giveaway that something is going on in
cylinder number 1 if I were to plug this back in I plug it back in nothing changes now
you can go one more and will this disconnect number two and you can hear
audibly that it’s gotten worse and you could do that with the other coils all
the way down to see if the tone of the engine and the vibration changes but in
this one dead giveaway cylinder number one is
dead because disconnected that coil and nothing has changed the engine is still
running rough so that’s a manual way without a scan tool that you can go
about doing this so a quick and dirty way to pretty much isolate the failure
to the ignition coil is to swap the coil that you suspect is bad into a cylinder
that you know is good so basically I’m gonna swap coil number one into cylinder
number two and I’m going to take coil number two and swap it in cylinder
number one just to keep track I’ll just throw a little paint mark the coil that
I think is bad and we’re just gonna go ahead and pull it
these are easy you just basically pull the tab up it’s going to eject the
connector and then you’re just going to pull it up and out now this is cylinder
number two you can see the boot is in really good shape and if we look at this
one right here tiny little hole right there and that’s where our misfire is
probably coming from so you got the coil swapped see the paint mark is now on
cylinder number two verse number one and again you could start the car do it the
non electrical diagnosis route and just see how the engine sounds by
disconnecting and that way you can isolate it to you to the coil or
something else going on in that cylinder but we’ll also do the scan tool route
and see that the misfire follows that coil all right so the f30
that would just happen to be doing this on uses the Delphi ignition coil from
the factory it just happened to have a bunch of these Delphi coils in stock so
turns out to be kind of convenient and the Delphi coils are kind of a dead
giveaway because they have the silver protective sleeve on them there’s three
different coils in this style from BMW there’s the Bosch coil which is all
rubber all black there’s this Delphi one which has the silver protects protector
sleeve on it then there’s the El door coil which is newly introduced it has a
black plastic protection sleeve on it instantly enough technically you could
install any three of those coils and the work but I always kind of like to put
back in what came out that way you kind of keep everything consistent especially
if you’re only replacing one coil if you’re replacing all four you could
probably swap in whatever you want and it’ll be perfectly fine but if we’re
just swapping one I like to make sure all the coils are the same manufacturer before installing the new coil I’ll just
put a small dab of dielectric grease on the inside of the boot that’ll prevent
it from sticking to the spark plug and making life a real pain later on when
you go to remove it don’t want to put too much just just enough to coat the
inside go ahead and drop it down and since I did remove this coil I’ll do the
same just ferp in measure now some coils will come with a little bit of
dielectric grease in there if they if they have it
I wouldn’t recommend adding it but these are totally dry so it doesn’t hurt to
add some I’m gonna make sure the coils are fully seated
we know the connectors are fully seated because you wouldn’t be able to flip
that tab down if it wasn’t we’re gonna go ahead and start the car and see if
the idles moved out all right so as you could hear the idle is totally smooth
now hundred percent confident that that coil was defective plus it did have the
actual physical hole inside of the boot which is always gonna cause a misfire
instead of the electrical charge going into the plug and then going into the
engine it’s going to totally bypass the plug find the closest route to ground
which is gonna be the side walls of the cylinder head that’s just the reality so
I hope you learned something if you liked the video hit the like button you
want to see more like this definitely subscribe we’ll do more short videos
like this on basic diagnosis and also if you have any questions feel free to
leave a comment we’ll get back to you soon as you can on that alright while
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