[Hybrid For Life]

Started my car at work today to get lunch and immediately notice shaking/vibrating from the engine along with a varying idle speed from about 500-800rpm. Drove car for a bit to see if it would clear out what seemed to be a missfire. Car sounded terrible and had very little power, shaking/misfire happening at all rpm ranges. Finally on the way back to work CEL light came on, after work I read the code with a code reader and heres what I got: P0304 Cylinder 4 Misfire Detected


I'm guessing its is directly related to me needing new plugs/coils as I'm still on the original set with over 112,000 miles. I plan on doing plugs first, what else could be causing this. Searched around a didn't find much specific to n52's

[MikeR1994]

At 112k I'd go ahead and change all 6 plugs. Start with that since it's relatively cheap and needs to be done anyway.
It could also be an ignition coil. To see if that is the problem, take the ignition coil from the cylinder that is misfiring and swap it with the one next to it. If the misfire is now in the cylinder that you moved the coil for cyl #4 to, that coil needs to be replaced.

[Johnny D]

You didnt search because if you did you would immediately find the answer.

[benzo23]

Originally Posted by Johnny D

You didnt search because if you did you would immediately find the answer.

+1 prob the most common failed part on a n52, guarantee its the ignition coil. I would replace all 6 plugs since you're over 100k and while you have everything opened up I would replace all 6 coils as preventative upkeep some will say to change them as they go out but what a pain in the ass every time just do it all in one shot. There really not that expensive anymore and the rest WILL fail eventually.

[MikeR1994]

Originally Posted by benzo23

+1 prob the most common failed part on a n52, guarantee its the ignition coil. I would replace all 6 plugs since you're over 100k and while you have everything opened up I would replace all 6 coils as preventative upkeep some will say to change them as they go out but what a pain in the ass every time just do it all in one shot. There really not that expensive anymore and the rest WILL fail eventually.

Aren't they still about $50-$60 per coil? Maybe I'm being overly frugal but I'd rather deal with doing them as they go out than drop $400 all at once for plugs and coils... Then again if I didn't have ongoing projects on my car I probably would. Maintenance is paramount though

[benzo23]

Ive seen them for less then 50. I just see it as convenient to do everything at once while youre under there. I mean do you want to take all the covers off 6 separate times and have 6 different misfires. If one is going the others aren't far behind. Just wise words of wisdom esp with 112k, Set it and forget it one less thing to worry about.

here is from ecs tuning, dbl check your part numbers this was just a quick search.,

http://www.ecstuning.com/BMW-E90-330....0L/ES1304983/

[Hybrid For Life]

Thanks guys, I was more wondering what else it would be if it doesnt turn out to be the coil or plugs?

[GoRomeo]

FYI I recently change my plugs at 100k miles and my coils look in good condition. If I were you just replace plugs first and go from there...

[Hybrid For Life]

Originally Posted by GoRomeo

FYI I recently change my plugs at 100k miles and my coils look in good condition. If I were you just replace plugs first and go from there...

thats the plan although I'm pretty sure its a coil also, doing plugs first and then seeing if the misfire is still happening, if so then i'll do the coil swap test

[GoRomeo]

Originally Posted by Hybrid For Life

thats the plan although I'm pretty sure its a coil also, doing plugs first and then seeing if the misfire is still happening, if so then i'll do the coil swap test

Cool bro... good luck and keep us posted. Cheers!

[monkey_wrench]

Originally Posted by Hybrid For Life

Thanks guys, I was more wondering what else it would be if it doesnt turn out to be the coil or plugs?

Lifter. Was there loud ticking as well?

[Hybrid For Life]

Originally Posted by monkey_wrench

Lifter. Was there loud ticking as well?

No, sounds like a misfire not lifter tick

[linlaoboo]

Hi there. My 328xi started getting cylinder 4 misfire around the same mileage as yours, 110k miles as of 2 days ago. We're have the coldest few days in the winter and the car shakes badly without any warnings during code start. SES light also came on when I started to drive it. I pulled a p0304 code, swapped #4 coil with #2 and got a new code p0302, however the p0304 code wouldn't go away. I then swapped it with #1 and wouldn't you know it, I then got all 3, p0304, p0302 and p0301 codes. Tried clearing the code from my cheap reader but couldn't. Yesterday I picked up a new coil from the dealer and put it into cylinder 1 and the misfire has gone away. However, all along I'm smelling a bit of gas or oil of some kind. Also noticed some metallic tapping or ticking sound at idle this morning. There's also a pending code p0107A that has something to do with some eccentric shaft sensor upon searching the net. From yesterday and today I was hoping for the codes and SES light to go away and luckily, after driving over 240 miles, the SES light finally turned off. I noticed the mpg dropped yesterday but it's back to normal today before the SES light turned off when I got home and restart the engine again to pull codes. Now things feels normal except I'm still getting the 3 misfire codes which don't make any sense. I don't feel any misfires and there were only 1 bad coil that caused the misfire in cylinder 4. The cylinder 2 and 1 misfire codes were generated after I put the bad coil into them. There's no more P0107A for now but I'm still able to hear the lifter tapping noise which never happened before the misfire started. I'm hoping the codes will only stay for so many cycles and go away like the SES light did but in my experience hoping isn't a good way to solve problems. This car's been running smooth with minimal work done including the VANOs sensor replacements during my ownership for the last 60k miles. Am I in for more surprises that'll cost a arm and a leg?

Have you come across more problems with yours?

[GoRomeo]

Originally Posted by linlaoboo

Hi there. My 328xi started getting cylinder 4 misfire around the same mileage as yours, 110k miles as of 2 days ago. We're have the coldest few days in the winter and the car shakes badly without any warnings during code start. SES light also came on when I started to drive it. I pulled a p0304 code, swapped #4 coil with #2 and got a new code p0302, however the p0304 code wouldn't go away. I then swapped it with #1 and wouldn't you know it, I then got all 3, p0304, p0302 and p0301 codes. Tried clearing the code from my cheap reader but couldn't. Yesterday I picked up a new coil from the dealer and put it into cylinder 1 and the misfire has gone away. However, all along I'm smelling a bit of gas or oil of some kind. Also noticed some metallic tapping or ticking sound at idle this morning. There's also a pending code p0107A that has something to do with some eccentric shaft sensor upon searching the net. From yesterday and today I was hoping for the codes and SES light to go away and luckily, after driving over 240 miles, the SES light finally turned off. I noticed the mpg dropped yesterday but it's back to normal today before the SES light turned off when I got home and restart the engine again to pull codes. Now things feels normal except I'm still getting the 3 misfire codes which don't make any sense. I don't feel any misfires and there were only 1 bad coil that caused the misfire in cylinder 4. The cylinder 2 and 1 misfire codes were generated after I put the bad coil into them. There's no more P0107A for now but I'm still able to hear the lifter tapping noise which never happened before the misfire started. I'm hoping the codes will only stay for so many cycles and go away like the SES light did but in my experience hoping isn't a good way to solve problems. This car's been running smooth with minimal work done including the VANOs sensor replacements during my ownership for the last 60k miles. Am I in for more surprises that'll cost a arm and a leg?

Have you come across more problems with yours?

I always recommend Chevron Techron fuel system cleaner before anything but is too late now. I ve seen many posts about this easy solution on cold starts. Also have you cleaned and swapped your VANOS solenoids? Research that. Keep us posted. Good luck

[linlaoboo]

Vanos solenoids were replaced around 80k miles

[linlaoboo]

sweet, I cleared codes again and it worked this time. Thanks.