'12 128i acceleration problem

[APC7654]

My 128i w/ 38,000 miles is intermittently is stuttering upon acceleration from start. It an auto tranny.

Got me puzzled,,, thought it was water in the fuel, but ruled that out. Even used different top tier fuels.

Being that it's intermittent, I don't think taking it in to the dealer will do any good.

Any ideas?

[jeddo45]

Code reader? Start checking the basics. Spark plugs and coils are usually the first place to start...

[Tarpon]

Clean or replace vanos solinoids.

[Lucky1]

Originally Posted by jeddo45

Code reader? Start checking the basics. Spark plugs and coils are usually the first place to start...

When it stutters does it make sort of a "rumbling" like vibration such as when you were to drive over rumble strips but coming from the engine instead of the tires? Thats how it felt when my plugs were bad and I was having cylinder misfires. Of course it never went away even after getting going and the car was only driveable at low rpms in any gear. Had to limp my way home at low revs.

[APC7654]

Lucky1,,,, it's nothing like you describe. It feels as if it is misfiring. It is extremely intermittent, and I'm trying to associate it with how I'm driving the car at that moment, but I'm not able to duplicate it.

Tarpon,,,, I know there was a recall on the vanos solenoids, but mine was not on the list.

Jaddo45,,,, does intermittent failure of coils or sparks show up on a code reader?

[jeddo45]

Originally Posted by APC7654

Jaddo45,,,, does intermittent failure of coils or sparks show up on a code reader?

Yes it does. I'm not sure if it will pop up on a generic code reader but for sure a BMW code reader. It will come up as cylinder misfires.

Does your check engine light come on and then go away?

[E91WAG3N]

Coils are a fairly common fail point on n51/52 and will cause idle to fluctuate. My car would almost die when coming to a stop and pushing the clutch in, I can't speak to how it might affect a slushbox. Code reader will confirm for sure.

[needexhaust]

Try resetting your adaptations

[APC7654]

Jeddo45 ,,,,, The check engine light has never come on.

No problem with the idle.

[WDE82]

Stop using commas instead of periods for your ellipses.

[APC7654]

UPDATE:

Filled up with top tier Shell and the problem when away. I was using a non top tier (cheapest gas), and now I'm wondering if they were putting in 87 octane in the 89 octane pump.

[WDE82]

Use 91-93 especially in FL. Hot environments make for hotter intake air which makes detonation easier. A higher AKI gasoline will prevent it.

[mackeroni]

Originally Posted by APC7654

UPDATE:

Filled up with top tier Shell and the problem when away. I was using a non top tier (cheapest gas), and now I'm wondering if they were putting in 87 octane in the 89 octane pump.

Glad to hear that your performance issue was solved so easily! In fact, it is a common problem which I struggle to understand. We spend top dollar for a well-engineered German sports car and then some of us fill the tank with substandard propellant. That's like forcing a professional athlete to perform at peak levels on a steady diet of fast food burgers and fries.

I apologize if it seems like I am flaming you personally. That is not my intent. I am sure you are a wonderful guy. And... you have lots of company. This specific problem pops up all too often. Please tell all your friends... cheap gas means poor performance. And worse, it can lead to expensive problems somewhere down the road.

Peace... Mack

[zx10guy]

Originally Posted by APC7654

UPDATE:

Filled up with top tier Shell and the problem when away. I was using a non top tier (cheapest gas), and now I'm wondering if they were putting in 87 octane in the 89 octane pump.

Originally Posted by APC7654

My 128i w/ 38,000 miles is intermittently is stuttering upon acceleration from start. It an auto tranny.

Got me puzzled,,, thought it was water in the fuel, but ruled that out. Even used different top tier fuels.

Being that it's intermittent, I don't think taking it in to the dealer will do any good.

Any ideas?

These two statements don't line up. So if in fact you were using cheap gas all along, you didn't help your cause by not presenting the facts correctly.

[MightyMouseTech]

Originally Posted by zx10guy

These two statements don't line up. So if in fact you were using cheap gas all along, you didn't help your cause by not presenting the facts correctly.

And why is he using 89 octane?

Not using the proper octane, let alone non top tier, and expecting the car the run properly are at odds with each other.

[zx10guy]

Originally Posted by MightyMouseTech

And why is he using 89 octane?

Not using the proper octane, let alone non top tier, and expecting the car the run properly are at odds with each other.

Exactly. The whole penny wise dollar foolish thing when people buy into cars like this. I'm as much as a tight wad with money as the next cheapskate. But won't try to pinch pennies on gas as it's not worth the risk...knock sensor or no knock sensor.