[Samster330]

Hi everyone, I have actually been a viewer of this forum for quite a while but never managed to make an account. This is the first time that I have not been able to find what I need on this forum soo here goes.

I drive a 2006 e90 330i.

I started to get random misfires about 2-3 weeks ago threw some Lucus fuel injector into my fuel tank then filled up a full tank and the problem seemed to go away. I dont know if it actually did or i just stopped noticing a few days later it started to come back. The misfires were very random had no direct correlation to how big of a load the engine was under. At the same time my MPG had dropped to an average of 15 mpg so i decided to change out my spark plugs and my air filter. This managed to bring me back to about 18.5 mpg, but the misfire continued to get worse and worse and eventually my "service engine soon" came on. At this point the misfires don't stop. They are continuous and very very annoying and probably beyond terrible for my motor mounts. So I went out and bought some MAF Sensor cleaner, and sprayed my MAF Sensor down, again no help at all. I got someone of craigslist to give me a OBD II read and got a P0301 reading which means "misfire in cylinder 1." I then swapped my cylinder 1 coil with my cylinder 2 coil and ran the test again and received the same code again.

I am now assuming it has to be my fuel injector but that is an expensive part for me to purchase and I'm not even sure thats the culprit. Does anyone have any advice? or idea of what it might/could be? I will post a video of the misfire in a bit!

thanks so much for the help!!!

[LegendGary]

Yea from the way it sounds you're going to have to replace that bad coil. Since the code said the missfire was on cylinder 1 thats the coil you will have to replace and everything should be fine again. Are you still on the original set of coils? if so it would be a good ideal just to swap all 6 coils. Good luck

[Samster330]

Originally Posted by LegendGary

Yea from the way it sounds you're going to have to replace that bad coil. Since the code said the missfire was on cylinder 1 thats the coil you will have to replace and everything should be fine again. Are you still on the original set of coils? if so it would be a good ideal just to swap all 6 coils. Good luck

I am on the original set of coils. Moving the coil from cylinder 2 to cylinder 1 gave me a p0301 code again which means misfire in cylinder 1. if the coil was bad it should have popped up a p0302 code which is misfire in cylinder 2. it did not so im pretty sure my engine coils are fine. I would change them but i am currently not floating in enough money to spend money on preventative maintenance.

In the last 2 weeks alongside this issue ive had
- Broken rear regulator $35
- Replaced air filter $25
- Rear view mirror snapped off and cracked my windshield $450
- Snapped passenger side stabilizer link $30
- Only realized this after a popped my passenger side tire and needed 2 new front tires $400
- New spark plugs $70
- I also have a malfunctioning driver side headlight that i have to replace

Basically as a college student i can't afford this shit lol.

[sunny]

remove the coil connector one at a time while engine is running and if you have a bad coil you won't get any difference in idle.
I also have 330i with 69K miles and I just replaced a bad coil.
ebay has em for $40.00 each.

[norsairius]

I had my car looked at for the same thing and they performed SIB 12-21-12 on it and it seems to be better. I unfortunately don't know any details about SIB 12-21-12. Anyone able to look it up? I can't find much on Google.

[Samster330]

Originally Posted by sunny

remove the coil connector one at a time while engine is running and if you have a bad coil you won't get any difference in idle.
I also have 330i with 69K miles and I just replaced a bad coil.
ebay has em for $40.00 each.

The misfire is only in cylinder one. I will try this but I'm pretty sure this is not the culprit. Thanks though!!!!

[3s4u2]

OP,

I am sure you did this..., but you did clear your DME adapts (codes)? It is kind of rare to have an injector fail on these cars. My 06 325 has over 200k on it and I have never had an injector failure. I have had a cam sensor fail which caused a misfire code to occur and the rough idle.

I hope you find the answer soon!

[Samster330]

Originally Posted by 3s4u2

OP,

I am sure you did this..., but you did clear your DME adapts (codes)? It is kind of rare to have an injector fail on these cars. My 06 325 has over 200k on it and I have never had an injector failure. I have had a cam sensor fail which caused a misfire code to occur and the rough idle.

I hope you find the answer soon!

I have not done this but through a little research i guess that means just pulling out the battery cable for overnight for my car to reset? If thats a fix to my issue i would be very happy!!!

Is that all i have to do is unplug the battery for 12 hours?

[3s4u2]

Originally Posted by Samster330

I have not done this but through a little research i guess that means just pulling out the battery cable for overnight for my car to reset? If thats a fix to my issue i would be very happy!!!

Is that all i have to do is unplug the battery for 12 hours?

Usually that requires and scan tool that has the capability to reset the codes, something like the PEAKE R5/FCX-3-16 or **************.com. BMW's store all codes and they must be reset to find out if the repairs completed have resolved the issues. Was the video you provided prior to getting a "service engine soon" warning?

[Samster330]

Originally Posted by 3s4u2

Usually that requires and scan tool that has the capability to reset the codes, something like the PEAKE R5/FCX-3-16 or **************.com. BMW's store all codes and they must be reset to find out if the repairs completed have resolved the issues. Was the video you provided prior to getting a "service engine soon" warning?

the video was after the engine light came on. The person that ran the OBD 2 scan cleared it for me so i guess it just hasn't been triggered again.

A member told messaged me telling me that even if i move the coil it does not mean the code will move to p0302 which is cylinder two so im going to try pulling plugs out one at a time to see if that makes an effect on the roughness of the idle. I will try that tomorrow and keep you guys updated thanks for all the help!!!

[petelazro]

Hey OP do let us know what the solution is if you figured it out. I am trying to fix the EXACT same problem for 3 months now. I am going to the dealer for the 3rd time in about 3 weeks to get it looked at again. They thought it was a software issue and did an update. I thought it had gone away but its back again. Its about +25C in toronto and the problem still persists in the morning after a cold start. The car shakes and the rpms go up and down 100-200 then level out after about 20seconds. there seems to be a lag on acceleration as well. Ill post back if they actually end up fixing it. Also they said no soft or hard codes were thrown so they are saying everything is normal.

[Munkee128]

Hi,

idk if this will help but my engine was shaking pretty bad during idle and I've been searching for the last few days and found this:

Although it was for a M3, I used the same method and it helped me diagnose the bad coil. Went and got a new one that same day and swapped it out and now it no longer shakes.

Hope this can help ya!

[Chriztofor]

Originally Posted by petelazro

Hey OP do let us know what the solution is if you figured it out. I am trying to fix the EXACT same problem for 3 months now. I am going to the dealer for the 3rd time in about 3 weeks to get it looked at again. They thought it was a software issue and did an update. I thought it had gone away but its back again. Its about +25C in toronto and the problem still persists in the morning after a cold start. The car shakes and the rpms go up and down 100-200 then level out after about 20seconds. there seems to be a lag on acceleration as well. Ill post back if they actually end up fixing it. Also they said no soft or hard codes were thrown so they are saying everything is normal.

I am getting tired of saying this, but if no codes are being thrown use Chevron Techron fuel injector cleaner (concentrate).

[jokers_greg]

update!

[irishfiend]

Update on this from anyone?? Sorry to necro - but I'm having this problem as well on cylinder 5-6. Replaced the coils with some minor improvement, same codes on same coils and essentially the same rough idle and misfiring occurring.

[bomorgan123]

For anyone trying to figure out this issue, give this thread a read: http://http://www.e90post.com/forums...d.php?t=922076

[riso1988]

Bump

Anyone ever resolve this? I’m having the same issue with a cylinder 4 misfire.

So far I’ve:
-replaced spark plugs
-replaced coils
-ran Techron through, 2 bottles
-replaced oil filter cage and oil cap
-replaced vanos solenoids
-cleaned vanos filters
-checked eccentric shaft sensor connector for oil (was clean)
-cleaned MAF

I’m at a loss here, thinking maybe a bad fuel injector? Figured that would throw a code specific though.

Additionally, I have a 2AA9 code which I believe is for the DISA #2 valve. But I’m pretty sure I’ve had that forever and never had any idle issues.

Any ideas would be appreciated! It’s an 06’ 330xi. Thanks!

[ZGator]

This was my experience with a persistent misfire:

https://www.e90post.com/forums/showthread.php?t=1674584

-did most things you did, replacing injector did not help either, I hope this is not your problem, I assume it was rare but who knows!

[Pilite]

A new set of coils seems in order.

[ro881e]

I had exact same symptoms on my 07 330i. Tried a few of the same fixes but the one that worked permanently was to replace the CCV system. Bitch to remove the manifold but issue never came back. Years stories of people chasing coil failures etc and wanted to try this first, glad I did!

[riso1988]

Thanks ZGator, nice post. Hoping that isn't my issue but glad to know it's a possibility.

Thanks Pilite but I tried that already and no luck unfortunately.

Thanks ro881e - I'm thinking this might be it. Although I changed the plastic CCV hoses when I replaced my starter 2 years ago. I guess it's possible that the diaphragm failed or one of the hoses brows or came loose. Going to try a smoke test tomorrow.

Tried replacing injector #4 today - no difference.

Other thought is maybe the vanos solenoids I bought are garbage? They were the doorman ones, thinking of swapping with oem as another test.

[riso1988]

Solved!

I performed the smoke test and ruled out a vacuum leak. Frustrated, I pulled the throttle body. It looked pretty clean (cleaned it probably 40k ago) but under the valve it was dark/dirty. Also I had a leaking valvetronics motor gasket so I replaced that.

Put it back together and have a steady idle! No more hiccups/surges during idle. Assume it was the throttle body cleaning but maybe the leaking gasket was influencing oil pressure?

Only issue now is it's still a little rough on a complete cold start for a second or two. Can live with it for now, going to try and replace the oil filter and see if that changes anything.