[donmcpeters]

Hello, all...first time poster here!

I own a 2010 BMW E93 6-speed manual with 65k miles (N52B30 engine). A couple of months ago, the engine began "stumbling/missing/hesitating" a bit - but only when in higher gears (like 3rd through 6th), only at lower RPMs, and only with a greater than normal load or when I'm accelerating hard. The greater the load, or the harder I depress the accelerator, the worse the "stumbling/missing/hesitating" becomes. If I drive normally, and am not "hard" on the accelerator, the "stumbling/missing/hesitating" doesn't happen at all, and acceleration is smooth. Also, if the RPMs are already relatively high, I can accelerate hard without the "stumbling/missing/hesitating" issue.

The vehicle has never thrown a code or issued any kind of warning, which is why I have my fingers crossed that the problem is something simple and inexpensive.

After doing some research, it looks like I may have to clean/replace the MAF sensor; or clean/replace the VANOS solenoids.

I just wanted some opinions on the matter. Do you think a good starting point is cleaning the MAF sensor and/or the VANOS solenoids? If you think this problem may be caused by something other than the MAF sensor or the VANOS solenoids, please let me know what else you might think be causing this.

Thanks in advance for your help!

[GoRomeo]

Originally Posted by donmcpeters

Hello, all...first time poster here!

I own a 2010 BMW E93 6-speed manual with 65k miles (N52B30 engine). A couple of months ago, the engine began "stumbling/missing/hesitating" a bit - but only when in higher gears (like 3rd through 6th), only at lower RPMs, and only with a greater than normal load or when I'm accelerating hard. The greater the load, or the harder I depress the accelerator, the worse the "stumbling/missing/hesitating" becomes. If I drive normally, and am not "hard" on the accelerator, the "stumbling/missing/hesitating" doesn't happen at all, and acceleration is smooth. Also, if the RPMs are already relatively high, I can accelerate hard without the "stumbling/missing/hesitating" issue.

The vehicle has never thrown a code or issued any kind of warning, which is why I have my fingers crossed that the problem is something simple and inexpensive.

After doing some research, it looks like I may have to clean/replace the MAF sensor; or clean/replace the VANOS solenoids.

I just wanted some opinions on the matter. Do you think a good starting point is cleaning the MAF sensor and/or the VANOS solenoids? If you think this problem may be caused by something other than the MAF sensor or the VANOS solenoids, please let me know what else you might think be causing this.

Thanks in advance for your help!

Always start with the minimum cost solution and start from there. Yeah cleaning MAF sensor and Vanos is always a good start. Look for shadow codes as well.

[Three_thirty_I]

^^ This, and don't forget the Check Valves that work with the Vanos Solenoids - they are mounted into the side of the cylinder head near the forward exhaust manifold. These things get pretty gunked up and can be the cause for these issues, and be very similar to a stuck Vanos Solenoid (or contribute to them misbehaving).

[GoRomeo]

Originally Posted by Three_thirty_I

^^ This, and don't forget the Check Valves that work with the Vanos Solenoids - they are mounted into the side of the cylinder head near the forward exhaust manifold. These things get pretty gunked up and can be the cause for these issues, and be very similar to a stuck Vanos Solenoid (or contribute to them misbehaving).

which valves are you talking about? I am replacing my Vanos soon thats why. What do you do with these valves do you clean them?

[simon]

I had the exact same issue. Stumbling / hesitation ONLY during low RPM, high throttle situations and silk smooth at higher RPM.

Turns out it was a coil pack going out.

Simon

[W37V]

Originally Posted by donmcpeters

Hello, all...first time poster here!

I own a 2010 BMW E93 6-speed manual with 65k miles (N52B30 engine). A couple of months ago, the engine began "stumbling/missing/hesitating" a bit - but only when in higher gears (like 3rd through 6th), only at lower RPMs, and only with a greater than normal load or when I'm accelerating hard. The greater the load, or the harder I depress the accelerator, the worse the "stumbling/missing/hesitating" becomes. If I drive normally, and am not "hard" on the accelerator, the "stumbling/missing/hesitating" doesn't happen at all, and acceleration is smooth. Also, if the RPMs are already relatively high, I can accelerate hard without the "stumbling/missing/hesitating" issue.

The vehicle has never thrown a code or issued any kind of warning, which is why I have my fingers crossed that the problem is something simple and inexpensive.

After doing some research, it looks like I may have to clean/replace the MAF sensor; or clean/replace the VANOS solenoids.

I just wanted some opinions on the matter. Do you think a good starting point is cleaning the MAF sensor and/or the VANOS solenoids? If you think this problem may be caused by something other than the MAF sensor or the VANOS solenoids, please let me know what else you might think be causing this.

Thanks in advance for your help!

Replace your coils. Probably one of them is bad, but it is not that expensive to swap them all out ~$25 each.

Bosh or Denso (pt# 12138616153) are acceptable.

[iahawkeye]

Sounds like you're on the right track op.

Dont buy anything before you know it's bad... Check codes if you can first. If it's a misfire that points more to an ignition coil. If you get other codes (something regarding intake or exhaust being wacky... I forget exactly) then it's something else, likely a solenoid or check valve.

Either way pulling codes will direct you a bit hopefully. Then cleaning the maf/vanos solenoids won't hurt either.... Supposedly you can swap their position to help determine failure just like an ignition coil but please double check me there first. And use the appropriate cleaner for the maf

[JuniorB]

Agree also with coils and fresh plugs,sounds like it's missing under load