[pizza_party]

I bought six of these (OEM) from my local dealer yesterday. Ordered off my VIN, part number I got was the same as the internet told me I should get, all seems well. Changing spark plugs too, using NGK ILZFR6D11s.

The issue I had is 5 of the 6 new coils don't fit properly. They don't seal fully between the rubber boot and valve cover (they are very easy to pop out, don't require much force at all) and the wiring connectors also don't engage fully, they can be forced to stay fully engaged (IE horizontal to the coil) but again, don't take much effort at all to pop them up. Anyway, I soldiered on, replaced everything, fired up the car, and it lit up like a christmas tree (4x4, dsc, brake, ses lights) and ran terribly.

I swapped the old coils back in (left the new plugs in there) and they installed back just like a coil should. Positive "thunk" upon inserting into the valve cover, the wiring connectors work just like they should, and the car ran beautifully. So I start troubleshooting replacing one coil at a time to figure out which ones are bad. Every time I install one that doesn't seem to fit properly, and start the engine (with 5 old but good coils) it runs rougher than it did. Only 1 of the new coils installed correctly, and I left that one in.

I call the dealer to again verify that the PN is correct for my VIN, and it is. I ask if they've ever heard of this and they say no. They say I can't return electrical parts, but I can pay them to put in the new coils I bought and diagnose what's going wrong. No thanks.

I compared an old and new coil, and the new one is slightly...just slightly...like half a mm longer (old one is on the right in pics)







Now I'm not above admitting "installer error" but I've done coils and plugs on BMWs plenty of times. And the fact that the original ones install so smoothly, run fine, and the new ones don't and run like crap, in addition to the slight difference in length, has me convinced there's something else going on. FWIW my build date is 06/06.

1) has anyone else noticed this or had trouble replacing coils on their N52?

2) knowing my original coils aren't going to last forever, what options do I have considering the official part simply doesn't work?

Those don't look right, for my 06 E90 330i, the newer coils are grey colored (updated PN) the originals were black.

When I look at realOEM it shows part number 12137594936 for cars built up to 04/2006, if your build date is before this looks like you have the wrong ones.


When you install them, they have to be aligned properly and you have to give them a strong push to seat them, you may not be pushing down hard enough, don't go crazy but its not a slight pressure.

If they still don't fit, I know there are a bunch of revisions to the spark plugs, maybe the newer plugs that go with those newer ignition coils are different length.

You should be replacing plugs/coils at the same time anyway (100k)
Make sure if your doing the spark plugs torque them to 30NM or 23 ft lbs dry.
Shot of compressed air into the tubes before you remove them is always a good idea.

Good luck.

[pizza_party]

Thanks for your thoughts. My build date is 06 of 2006. I've narrowed it down to the boot of the new coils is rejecting the plug, thus not maintaining solid contact between coil and plug (which also explains why it doesn't like to seat on the valve cover like it should). The boot is of a different design and that must be the difference. I can force the plug to make contact with the coil but as soon as I let go it pushes out 1/4" or so losing the contact. It is like this with the OEM ILZ plugs and the new ones (exact OEM P/N). Again, the old style boot allows the plug to maintain contact just fine.

I went to the auto parts store and tried out every iridium plug they had in stock for the N52, and the story was the same with all of them. According to realoem BMW ended a few different part numbers for the plugs, with the updated PN a 12-12-2-158-253. I will try these out and report back, but it seems the following plugs are not compatible with the ignition coils ending in 937 due to the boot rejecting the plug:

Denso SK20HR11
NGK LFR6AIX-11
NGK ILZFR6D11

[scotty_miller]

+1 on everything index1489 said. My 330 has a build date of 10/2005 and I used the ones in the picture above. I'm almost positive the dealer ordered you the wrong ones. Return them and order ones from ecs tuning they'll hook you up with the right ones

[.fLip.]

had this issue when getting coils from napa. advance auto and autzone. while they were similar they were a diff enough to not even click in. I ended up going to the stealership and it was actually cheaper, go figure lol.

but the dealer shouldn't get u the wrong one. they check by ur vin and go from there. when I ordered from the dealer it was EXACTLY the same. switched it right in the parking lot lol

[longnvu]

I would go back to the dealership and speak with a difference parts clerk or a manager. Especially if they refuse a return, when they made you buy the wrong parts...

[pizza_party]

My build date is 06 2006. I was sold the correct coils for my build date (according to realoem), which were apparently updated along the way. They are not compatible with the original NGK spark plugs which have been superseded with the PN in my other post above (I'm assuming in conjunction with the updated coil design). I'm confident this is the problem. Before buying new plugs I will test them at the parts counter with the new coils to ensure they make contact with the plug correctly. If for some reason they don't...then the dealer will have some explaining to do

[TRoN]

I own a 2006 323i(Canada) production 06/06. I just bought the same coils from a parts store, not dealer(also 6 new spark plugs). They are Bosch and look exactly like the ones you bought(the one on the left). My originals are also Bosch and they look exactly like the one on the right. I too had problems with theses coils. I don't think the exterior length is an issue. I noticed the original coil, when you look inside the opening, has a metal tab/clip close to the end(about 1" or so) that snaps onto the spark plug. The new one does NOT have this metal clip and the only metal I can see is much deeper in and smaller(diameter). When I insert the spark plug in the new coil, it doesn't seem to make contact with the electrode inside. Maybe there is something missing? Or different plugs are needed for this new coil(longer?)

The reason I bought the new coils is because one original coil died. When I replace all 6, the engine mis-fired badly. I put back 5 originals and left one new one in(third from the front, I guess #3?) and It seems to be running fine. I confirmed that #3 is firing by disconnecting/reconnecting while engine is running, although I don't know how since the spark plug doesn't seem to reach the electrode inside the coil.

As for the build month, the parts store said there are 2 types, before 04 and after o4(month). The other type look the same but are grey and the power connector will not plug into these.

So what ended up being the issue new plugs?

[pizza_party]

Been very busy with work and some other maintenance on the car.

My experience is identical to what Tron posted (except that the only new coil in my car is on cylinder #6). I too noticed the inside of the new coil didn't have the metal sleeve to encase the spark plug, which is what I think gives the old plugs into the old coil such a positive engagement. Wonder why they changed...save a few cents per coil perhaps...

Since replacing the spark plugs (with the original P/N plugs) solved the misfire I was chasing this has become less of a priority. I ordered the "correct" updated number spark plugs, when they arrive I will try them with the new coils, and report back.

[TRoN]

I suspect the one new coil I used is not actually making contact with the new plug, but is close enough so the spark jumps to the top of the plug (which then obviously carries the high voltage to the plug gap). When I insert a plug into the new coil while holding in my hand, I can feel the plug is not reaching or contacting anything inside(by bending the coil pack at the supposed junction point). Maybe these Bosch coils require different plugs? Maybe there is something that can be inserted inside the coil opening?

My original BMW plugs(BMW stamped so I assume they are original) looked exactly the same length and shape as the new NGK iridium plugs I bought.

[mike-y]

The harness plug for the coils is slightly different. I had a similar issue with my '06 with a 5/06 build date.

when I bought a new set of coils, RealOEM, and all the parts suppliers said I needed the newer style coil, since my car was built after 4/06. When I finally had a coil go bad, the new coil didn't fit properly. The big difference was in the plug connector, where the new plugs require a centered slot on the car harness plug, and the older one is offset.

since I was in a bind, and none of the local stores carried the "old" style coil, I used a hacksaw to cut off the piece of plastic that kept the plug from fitting 100%.

I was able to contact the supplier on amazon to return the other 5 coils, and they insisted that I had the right PN based on my VIN. Luckily, their warehouse was about 10 minutes from my work, so I went there one day and confirmed that the older PN is what I needed to fit my car.

Everything says cars built after 4/06 get the new coils, but it seems that is not correct.

here is a pic of the coil with the center fin under the plug. This is designed for plugs with a center slot. If the slots on your plugs are offset to one side, you need the older style coil.

[TRoN]

To me both coils(on or before 4/06 and after 4/06)look the same, except for that slot preventing the harness from plugging in properly. The issue I and pizza_party have is inside the coil opening is different from the original coils(both made by Bosch). Mike-y, can you show is how that coil looks like looking in at the opening. Also are they Bosch?

Thanks

[GoRomeo]

Me to Ill be buying new coils soon. Interested on the outcome. I guess I need to check what month and year my car was built. I was going to buy these...but did not.

http://www.ebay.com/itm/271274636151...84.m1423.l2649

[mike-y]

both coils are made by Bosch. The "newer" coil I had looked like Pizza's pic in the OP (the coil on the left).

it worked perfectly fine after I cut off the fin, except that the plug didn't feel quite as tight with the tab locked down. I ran with the modified coil for about a week until I got the correct "old style" coils.

the distributor told me the coils are identical on the inside (voltage spec, etc). The length looked the same to me (though I didn't actually measure), and like I said, the new coil worked once I trimmed off that plastic fin.

[DRock3d]

I just used one of these new coils. Installed fine and works fine so far.

[bimmerquick43321]

you guys are scaring me, I need to buy coils and I'm not sure which ones I should buy anymore.... the more I'm thinking the more I'm going to buy them through my garage and have them change them, if they got the wrong ones, they'll have to deal with it.

[///M3NACE]

What's your production date just go by that you'll be fine. It's on the door jam

[mike-y]

Originally Posted by ihsanshaik

What's your production date just go by that you'll be fine. It's on the door jam

except we've been discovering that going by the build date is actually not correct, lol.


you can always just look at one of the wiring plugs for the coils and see where the slot is. if it's centered - new style. if it's offset - older style.

[bimmerquick43321]

Originally Posted by mike-y

except we've been discovering that going by the build date is actually not correct, lol.

you can always just look at one of the wiring plugs for the coils and see where the slot is. if it's centered - new style. if it's offset - older style.

The problem is that getting to the wiring plug, I have to take appart pretty much everything as I would if I actually change them and at -20Celcius, not really feeling it... is there an easier way to find out?

[mike-y]

Originally Posted by mecbain

The problem is that getting to the wiring plug, I have to take appart pretty much everything as I would if I actually change them and at -20Celcius, not really feeling it... is there an easier way to find out?

-20C?

ouch.


yes, you'd have to remove the cowl tray on top of the motor, and then then plastic cover over the engine. it's not hard at all, but at -20C, I don't think I'd be very motivated to do it either.

out of curiosity, what is the build date of your car?

[bimmerquick43321]

yeah pretty cold, last week it was close to -30 with the wind factor, good thing is that my car started with no issues.

For my production day it says 01/06 as per picture below, that means january 2006 right? not the 1st of June? lol just making sure

So in this case this should be a no brainer for me, I have to get the pre 03/06 ignition coils right? with the ILZFR6D11 NGK spark plugs?