[alep85]

Hi all.....just an FYI for others dealing with plug/coil misfire issues, this might give you all some help in diagnosing your own car in the future!

My wife's '09 328i xDrive hit around 45k miles so I proactively replaced the plugs and coils.

So I replaced all 6 coils and plugs with Bosch coils and plugs from ECS Tuning (as usual, the experience in dealing with ECS was great, no complaints there). Really easy DIY, took less than 20-30 minutes tops.

What I found a bit weird is that although they looked exactly the same as the BMW factory-installed Bosch coils/plugs, I noticed that the connector clip on the top of the coil was a bit flimsier than the originals. Also, the connectors didn't seem to want to clip in as snugly as the originals.

After installing them with issues on initial startup, about a week or two later the car started idling REALLY hard after full throttle acceleration and then threw a check engine light. I figured a coil was bad because cylinder 5 showed a misfire, so I got a replacement.

After putting in the replacement, it idled even WORSE! So then I started to freak, thinking it was the injector or something.

So I hit full throttle with the engine cover off, and noticed several of the plugs' connectors slipped back about a millimeter or so. One slipped back so much, the clip popped up!

So I popped all the clips up, and noticed that unlike the original ones, many of them did not seat all the way into the connector when you closed the clip (which on the E90's, pushes the connector into the coil). So I put some force on the connector and got it seated before closing the clip, so there was no longer a 1mm or so gap.

Started it back up, voila, no more issues. Drove it hard around town for a couple of miles, no more issues.

Hope this helps anyone with random misfiring issues on their E90!

TL;DR......if your brand new coils are misfiring, double check the connectors and ensure there's no gap, and that the connector is all the way into the coil as far as it can go! Seems like the aftermarket Bosch coils look like the BMW originals, but the connector clips are shittier and don't seat the connector as tight without some elbow grease.

[The Nightman]

Thanks for the heads up. What is the part number of the coils? This is the second time I've seen this recently

http://www.e90post.com/forums/showthread.php?t=1401886

[El Cheapo Loco]

This is true for any brand/style coil. Pressing down the clip does not mean the connector is seated all the way. You have to press hard on the connector to ensure a good connection.

[alep85]

Originally Posted by El Cheapo Loco

This is true for any brand/style coil. Pressing down the clip does not mean the connector is seated all the way. You have to press hard on the connector to ensure a good connection.

Ehhhh......not like this.

I've replaced them before with BMW branded ones (ironically, still manufactured by Bosch) on my other 328i, and once you get it seated on the connector, the clip brings it all the way flush as far as it can go.

[alep85]

Originally Posted by freedomfries

Thanks for the heads up. What is the part number of the coils? This is the second time I've seen this recently

http://www.e90post.com/forums/showthread.php?t=1401886

They're Bosch brand, but not the Genuine BMW Bosch ones sold at the dealership.....they're aftermarket.

I don't have the part # handy because ECS Tuning's site is down, but once it's back up I'll pull the part.

I'll say that they work as good as the genuine ones now that I've got the connector on there properly, but this is more an FYI for those installing them that the connector is really finicky and you want to make sure it's shoved in there REALLY good. Otherwise, you're going to get issues that make it seem like you got a bad coil or plug.

[bimmerlove335]

This happened to me recently as well, but I got them from fcpeuro. Turns out 3 of the 6 had this issue. I sent them back for replacements which seemed to remedy this issue.

[123Britt]

Are Eldor not the latest improved coil packs?

[alep85]

Originally Posted by 123Britt

Are Eldor not the latest improved coil packs?

I don't know. My '09 had Bosch from the factory, so I replaced them with the ECS Tuning coil/plug set (Bosch, non-BMW branded). Eldor didn't pop up as an aftermarket option, for coils I only saw Bosch or Delphi.

[123Britt]

Found this:



http://www.e90post.com/forums/showthread.php?t=1202250

[alep85]

Originally Posted by 123Britt

Found this:



http://www.e90post.com/forums/showthread.php?t=1202250

Yeah, I see them, but those are not aftermarket. I didn't feel it was worth the dealer markup $$$$$, and now I've got these Bosch aftermarket ones working just fine.