rev up your engines here we got a 12 year old BMW that isn't running right no
surprise there it's running like crap the check engine light is on so let's scan it
hook the scanner up to the data port and what does it say P0306 cylinder #6
misfire detected now a misfiring in any one cylinder can be whole bunch of things can be the
ignition system the fuel system blowing head gasket a bad valve all
kinds of stuff but all we start basically we're gonna go to number six
let's see what's going on they'll be able to BMW you can't even see the spark plug so
we're gonna take this plastic crap off in this case it's a five millimeter hex
head touch these stupid things off oh it makes them look so great doesn't it
just makes it a pain to work on plain stupidity some of these designs you got to
take half of this stuff apart to access it to get it off another brilliant
German design yeah we'll take these clips off tomorrow over here get this
out of the way so we can slide to cover up they get to the spark plugs up here
the number six is hiding way back here so we'll check that first and now you
can see why I think so little of BMWs modern ones look all plastic crap this
is all plastic crap you gotta pull a little line off the coil and then it's
theoretically just pulls out but these are stuck cuz they're twelve years old
and they're gonna be cows to get out plastic old aged heat on the engine and
then the stupid cover on top of it to hold the he didn't even more so the
plastic retains heat and cracks even more let's hope nothing breaks when we
take it off but don't be surprised if a bunch of this plastic crap start
snapping off in your hands you'll just have to replace it then you got a pool
of coils up not an easy thing to do it's all plastic and it may crack and you
just gonna have to buy a new ignition coil if it does my trick is to get a big
pry bar start to pry them out cuz they're sitting in there there's no bolt
holding them in like a batter made Toyota where the coils are bolted on
these are just placed in butt and rubber and plastic hey it spun on it for 12
years so it's often real be hard to get off and you'll often
break stuff but here goes nothing we try some prying and pray pray and prying no
won't come out though now it is easy to work on the front one so I got the front
one out and there's a point to this if I ever do get the back number six one off
without breaking it what I'm gonna do is check the spark plug see the spark plugs
okay and then I'm gonna put the number two coil here on number six and number
six on number two and if the misfire moves to number two then we'll know it's
just an ignition coil it's as simple as that when you only have one misfire
for one cylinder can finally get the spark plug ignition coil off you'll see
they have weird spark plugs typical BMW crap you see they're not regular hex
heads they got these translations but fortunately if you have a fourteen
millimeter socket it does fit over it you do not have to go to BMW to buy a
fancy socket a plain old fourteen millimeter socket will work to get it
off course the crenulated one works better but here's a plain old regular
hex one you wiggle it it goes right on it'll hold it to take it off you don't
have to buy that special tool but you got to have a fourteen millimeter thin
wall deep socket do you'll never get the stupid thing out it's not a regular
sized spark plug now with a ton of wiggling and prying and then waiting to
get it off because of course there's no working room in the back of the engine
out comes the stupid number six ignition coil there it is now of course it could
be a bad spark look so I'm gonna take that spark plug out and put a new one in
just in case now even that's bad cuz theirs not much working room
and oh man I had to put three different sized extensions in and get it deep
enough but it seems to be coming loose and yes I can turn it with my bare hands
now a lot of work voila finally and as you can see here I had to have various
wiggling extensions so I put it in with just short one then when that falls in
you put this on top so you can get the socket and get your ratchet to take it
off but then when you pull it off it won't come out so you got to pull it off
partway then take off that and then get the rest with the spark plug now it
doesn't look horrendous but all the work on this I'm not
taking a chance maybe it's bad electrically inside so I'm just gonna replace it with
a new one just be sure to replace it with the same plug these are both bosch
plugs well tighten the new spark plug in no working room of course and this case
I'm using the stubby ratchet because there's more room for tightening up
where it still takes a while but you can see the stubby one you can turn fast
then for the final part use the peg one and now comes the logical part this is
the number six ignition club I'm gonna put that on number two to put number two
on number six then when we drive it if the cold goes to number two you'll know
it was the coil that caused a problem in the whole place you don't want to guess
with these things they're pretty expensive on BMWs so before I forget I'm
gonna put the number six on a number two right now and it goes they go in a lot
easier than they come out they're just plugging hole in the connector just
snaps in and you lock it with the top then we got to do it in the back I can't
film that there's no room but it's the same process
then we use a scan tool to erase the codes you can see codes remaining zero
and start it up just don't forget to put the air filter back on make sure
that's all tight well here goes nothing well hopefully something
now we'll take it for a spin and see what happens well that didn't take long
the check and you I had already come back on so let's see what the magic
computer says magical enough it now says code P0302 cylinder number two misfire
alright we didn't fix it yet but now we know it's the ignition coil cuz we put
the number six ignition coil on a number two and the misfire removed from number
six the number two so we know that coil is bad we'll put a coil in it so we get the
brand new coil and swap out number two again so this time we'll just move
this out of the way a little unplug it out it comes and there goes the new one
back in the hole plug it in make sure it's lined up right on snap it in place there
we go but the stupid bolts back on ridiculous
covers I don't know why they didn't bother and this time we should have
better lock sounds a lot better already no more of that backfiring
well we gotta check it for a road test anyway and as you can see now it's idling
smooth but watch when you step on the gas it goes no more hesitation so
the next time your BMW or any other car starts misfiring now you know how you can
fix it yourself, so if you never want to miss another one of my new car repair
videos, remember to ring that Bell