[Fc4rockstar]

Hello guys I NEED HELP. I own a 2007 BMW 328i and it has a constant misfire. I changed all of the spark plugs and coils and I still get a misfire in cylinder 4. The misfire used to come and go but now it doesn't leave at all. I have no idea what the problem could be. I even changed the fuel injector with a BMW OEM one. A few days ago the car didn't have it until one night I drove over a 110mph and when I came to a stop the car started misfiring. Ever since then it hasn't gone away.

[MTK24]

Check and connection on the wires/plugs. Did you try moving the plugs and wires around and see if the misfire changes cylinders?

After this I would check injectors. Could be a bad injector

[Fc4rockstar]

Originally Posted by Vampire335i

Check and connection on the wires/plugs. Did you try moving the plugs and wires around and see if the misfire changes cylinders?

After this I would check injectors. Could be a bad injector

I actually have tried moving the wires and plugs around and had no luck. I also replaced the injector with a new one from the dealership but I came to no luck as well. I've seen posts of people talking about that it could be the ecu. I googled it but I found extremely little information on that. By any chance, do you have any clue?

[tristanwrogers]

If you wouldn't mind me asking, what symptoms does the car have while driving?

I think my 328i may be misfiring but I don't have any diagnostic tools to confirm. Is that Carly?

[Fc4rockstar]

Originally Posted by tristanwrogers

If you wouldn't mind me asking, what symptoms does the car have while driving?

I think my 328i may be misfiring but I don't have any diagnostic tools to confirm. Is that Carly?

It pretty much shakes when I'm at a stop. The symptoms are pretty much the same as a normal misfire but this one will not go away. I've tried everything that I could think of. Yes that's Carly that I'm using. I even used a bmw dealership scan toon that my mechanic owns (certified mechanic for bmw) and it pretty much says the same error. I used a different app and the code came out to "injector circuit malfunction cylinder 4". To me it sounds the same as Carly but maybe you may have a idea what it could mean.

[Pladi]

Originally Posted by Fc4rockstar

It pretty much shakes when I'm at a stop. The symptoms are pretty much the same as a normal misfire but this one will not go away. I've tried everything that I could think of. Yes that's Carly that I'm using. I even used a bmw dealership scan toon that my mechanic owns (certified mechanic for bmw) and it pretty much says the same error. I used a different app and the code came out to "injector circuit malfunction cylinder 4". To me it sounds the same as Carly but maybe you may have a idea what it could mean.

So if the plugs are changed and the coils you are left with :

1 Injector Swap them see if it follows

2. You need to perform compression test on that cylinder.

[Fc4rockstar]

Originally Posted by Pladi

So if the plugs are changed and the coils you are left with :

1 Injector Swap them see if it follows

2. You need to perform compression test on that cylinder.

I will try to get a compression test done on the car. I have a question, what is the car fails the compression test? What could be a fix? And how is the failure caused?

[blackturbo]

Please don't take this as a insult, as I'm just your friendly neighbourhood spiderman trying to help.

Did you happen to check if the spark plugs are torqued properly? Are the coils seated properly? Double checked connections?

[Fc4rockstar]

Originally Posted by blackturbo

Please don't take this as a insult, as I'm just your friendly neighbourhood spiderman trying to help.

Did you happen to check if the spark plugs are torqued properly? Are the coils seated properly? Double checked connections?

Haha no problem, yes I did check all of those factors, but I did not torque them down to spec. I just made sure they were nice and firm without over tightening them. The misfire actually went away yesterday for the whole day and then came back today's morning. I did not touch the engine bay for about 1 and half now. Not sure how the misfire went it away and then came back

[Pladi]

I dont want to scare you but if your car fails the compression test on that cylinder its pretty bad news. Major head rework needed.

Another thing i would do is reset the ECU completely. So unplug a battery terminal and discharge the ecu/dme votlage. Its probably similar to adaptation reset. Maybe more.

[dmatre]

Originally Posted by Fc4rockstar

Haha no problem, yes I did check all of those factors, but I did not torque them down to spec. I just made sure they were nice and firm without over tightening them. The misfire actually went away yesterday for the whole day and then came back today's morning. I did not touch the engine bay for about 1 and half now. Not sure how the misfire went it away and then came back

This sounds like a loose connection. I had a misfire, troubleshot & found my coil 5 bad. Replaced all 6. Was perfect for 2 days, then misfire returned. Pulled it apart again and found that one of the coil latches that lock the connector to the coil was not fully engaged. Misfire would come & go for the hour it took for me to get home & dig into it.

Check this. Also, the connectors for coils 2-5 are very tight due to the tie wraps on the harness. Is it possible that you 'tweaked' one of these connectors during your past work?

[Fc4rockstar]

Originally Posted by dmatre

This sounds like a loose connection. I had a misfire, troubleshot & found my coil 5 bad. Replaced all 6. Was perfect for 2 days, then misfire returned. Pulled it apart again and found that one of the coil latches that lick the connector to the coil was not fully engaged. Misfire would come & go for the hour it took for me to get home & dig into it.

Check this. Also, the connectors for coils 2-5 are very tight due to the tie wraps on the harness. Is it possible that you 'tweaked' one of these connectors during your past work?

Very interesting, I will definitely check that out. Well the misfire actually started when I changed my valve cover the first time because it was cracked. Maybe I pulled something and the connection got loose. My car never misfired until the valve cover replacement. Thank you I will check it when I have free time to work on the car

[nsjames]

my misifre was a terminal on the injector that did not grip the spade tightly.

Pull the injector harness and use a pick to bend the center of the female terminals together.

Look on the injector male side for witness marks that are lighter than the others. That's how I finally found mine.

[Fc4rockstar]

Originally Posted by nsjames

my misifre was a terminal on the injector that did not grip the spade tightly.

Pull the injector harness and use a pick to bend the center of the female terminals together.

Look on the injector male side for witness marks that are lighter than the others. That's how I finally found mine.

Thank you, I'll try this tomorrow

[robygomez]

Hope not to repeat, but I´ve just had the same problema last weekend and it happened to be the coil number 4, just switch it to position 1 and the scanner told me the problem was now in cylinder 1 so I bought a new coil and voila!!!

[parkjake50]

Hi, when i come to a stop light, in D mode, it will start to randomly shake while foot being on the brake. Is this like the same symptom you were experiencing?