[MB07]

I just purchased this car about a month ago, when I test drove it, it was on fumes so the salesman told me he would put gas in it, filling the tank half way with 89 octane (I found this out a few days later when he finally emailed me back). While driving home in my new car it started sputtering and misfiring and gave me a check engine light but the engine light would turn off after a bit. Took it took a guy locally who specializes in BMWs and gave the entire car a check and told me it was a super clean car but had a misfire on #4 which was probably due to the 89 fuel because the spark plugs still looked good.

I have since take 2 tanks of 91 through it and 1 bottle of Seafoam to clear everything out. The sputter is less frequent now but still happens. I have narrowed it down to when the car is in a higher gear and I have to get on it enough to where the engine needs to downshift where the seems to hesitate and sputter but after a second finally finds itself. When I am manually shifting this I do not have this problem at all. Only when I am in auto shift.

I have been look all over these forums to try and find an answer but no such luck. The only ideas I have are spark plugs need replaced, could be the fuel pump or it sounds like a Vanos issue but my engine is a N52 and I thought that was a N55 thing.

Car is a 2009 328i xDrive with 66,xxx miles. Only engine mods are carbon filter delete, K&N filter and Cyba scoops.

Appreciate any help given.

[NGEE]

You need to invest in a code reader. Not the Advance Auto kind, but a BMW code reader like the BavTech.

[monkeybingo]

hmm 89 gas shouldn't really cause that issue. may be it was a bad car to start with?

[07chupacabra]

Bluetooth OBD reader for ebay for $20, BMWhat app for $50. Peace of mind.

[AllBlackBimmer]

vacuum leak
Eccentric shaft sensor

I doubt it is the spark plugs or fuel pump.

[MB07]

Originally Posted by NGEE

You need to invest in a code reader. Not the Advance Auto kind, but a BMW code reader like the BavTech.

BMWhat Wifi adapter will be here Thursday.

[MB07]

Originally Posted by AllBlackBimmer

Eccentric shaft sensor

I hope thats not the case. I hear they are expensive and a bastard to change out. Ill unplug it tonight and hope for no oil.

[Bavarian Tech]

Plugs are due at 60k, suggest replacing them. Also replace ALL coils. Yes you can get away with doing one but the rest are following behind that failed one. BMW issued a updated SIB to replace all Bosch coils with Delphi. Just a friendly FYI

[thomas88162]

Technically plugs aren't due until 100k for N52's, but I wouldn't personally go that long without changing them. I am in complete agreement with the notion that you have bad coils, though. I would recommend replacing them.

[Bavarian Tech]

Originally Posted by thomas88162

Technically plugs aren't due until 100k for N52's, but I wouldn't personally go that long without changing them. I am in complete agreement with the notion that you have bad coils, though. I would recommend replacing them.

Technically thats half true. N51/N52 up to 3/09 are 100k after 3/09 its 60k.

[Douche]

I don't know who's right, and I don't care.

But my car requested me to change plugs when it turned 80000 km, and when I replaced them, I reset the thing and it now will request change with 160000km.

So just throwing a hard fact out there and people can choose to believe whatever they want

[thomas88162]

Originally Posted by Douche

I don't know who's right, and I don't care.

But my car requested me to change plugs when it turned 80000 km, and when I replaced them, I reset the thing and it now will request change with 160000km.

So just throwing a hard fact out there and people can choose to believe whatever they want

Well, yours is a 2007. SO I'm technically right . That doesn't really matter, though. You shouldn't wait that long to do spark plugs as that is an insanely long time.

Still, the OP likely needs new secondary ignition if its misfiring under load.

[Douche]

Originally Posted by thomas88162

Well, yours is a 2007. SO I'm technically right . That doesn't really matter, though. You shouldn't wait that long to do spark plugs as that is an insanely long time.

Still, the OP likely needs new secondary ignition if its misfiring under load.

How are you right though? Maybe I missed your post.

Some posts above are saying to replace plugs in 60 or 100 k miles. No plugs last that long.

[thomas88162]

Originally Posted by Douche

How are you right though? Maybe I missed your post.

Some posts above are saying to replace plugs in 60 or 100 k miles. No plugs last that long.

I am the one who said 100k, that was just always the spec BMW put out for their plugs for NA engines until they decided otherwise. I would agree that plugs are severely degraded by that point in time, although they usually still somewhat work. Its not really a matter of right or wrong, more like don't follow BMW's maintenance schedules, just like their lifetime fluids.

[MB07]

Originally Posted by thomas88162

Well, yours is a 2007. SO I'm technically right . That doesn't really matter, though. You shouldn't wait that long to do spark plugs as that is an insanely long time.

Still, the OP likely needs new secondary ignition if its misfiring under load.

I found the Delphi coils (GN10328) on Amazon for $32 each, that seems like a good deal from what Ive seen. While I am in there I might as well change the plugs.

[thomas88162]

Originally Posted by MB07

I found the Delphi coils (GN10328) on Amazon for $32 each, that seems like a good deal from what Ive seen. While I am in there I might as well change the plugs.

No doubt about it you should! You will be amazed at how much smoother the car will run in general with fresh plugs. I am merely stating that your sputtering (IE misfiring) problem under load is likely wonky coils or one that isn't clipped down all the way.