[dangeris]

So, like the subject says, there are times when the car is in the drive mode, and when I step on the gas, the car hesistates then the check engine light comes on. When I step on the gas, it seems like the choke is on as the car loses power and "tries" to get up to speed. If I lay off the gas and drive modestly, the CEL lights sometimes goes off. Other times when it happens, I pull off to the side of the road, turn off the car then restart it and all is good again., It never did this before and it seems to start happening a couple of months ago.

Has this happened to anyone else out there? If so, what could be causing it? throttle position sensor?

[Tim603]

Did you run the code?

[dangeris]

No I haven't. When it happens Im no where near a shop that can run the code and when I do the code clears..

[bhmax16]

Even if your light turns back off the code should still be stored in your history. BT tool and the like can pull history codes

[Casca]

I'd start by cleaning out the mass airflow sensor with http://www.amazon.com/CRC-05110-Mass...sensor+cleaner . Search on this site for how to do it, very easy and takes 5 minutes or so.

[bimmerquick43321]

I had very similar problem when ignition coils/sparkplugs needed replacement.

[dangeris]

How many miles was on the clock when that starting happening? I have 83K on mine

[GoRomeo]

I sometimes I experience some hesitation. I did replace my spark plugs but NOT my coils. Still running on originals at 117k miles. I think I am due for new coils hopefully the hesitation will go away.

[GoRomeo]

I noticed that when turning on a curve at low speeds I experience a little jerk in speed and hesitates. I tested my coils by unplugging each one with car running and they are all are good. I will do a bottle of Chevron to clean my injectors. I will also clean my MAF sensor. It has been about 2 yrs since I cleaned it. Anyone else experiencing this...?

[Volasko]

It could be your vanos solenoids. Do you have situations were the RPM needle seems to have a mind of its own and fluctuates up and down? Sometimes the solenoid valve gets clogged and causes the engine to run sluggish and throws a code. Do a search, it is an easy fix.

[GoRomeo]

Originally Posted by Volasko

It could be your vanos solenoids. Do you have situations were the RPM needle seems to have a mind of its own and fluctuates up and down? Sometimes the solenoid valve gets clogged and causes the engine to run sluggish and throws a code. Do a search, it is an easy fix.

I see situations only at times were my RPMs are higher than normal even when engine warm, but I thought this is caused by my open thermostat I have had for over 2 years. I cleaned and swapped my vanos solenoids about 2 yrs ago. I get no codes or anything. Maybe I need to replace them now? I will read more on these... Thanks

[Delta0311]

Could be any of the following
dirty MAF
bad ignition coil
worn out spark plugs
bad VANOS solenoid

[GoRomeo]

Originally Posted by Delta0311

Could be any of the following
dirty MAF
bad ignition coil
worn out spark plugs
bad VANOS solenoid

thanks, I will start by cleaning my MAF, I already changed my spark plugs last year so I dont think this is the issue. I tested Coils and all are good.

Vanos? maybe, I cleaned them and swapped them once, still on originals but I get not codes though... how do I test these suckers...

[Delta0311]

Originally Posted by GoRomeo

thanks, I will start by cleaning my MAF, I already changed my spark plugs last year so I dont think this is the issue. Vanos? maybe, I cleaned them and swapped them once, still on originals but I get not codes though... how do I test these suckers...

If you get no codes then I doubt is the VANOS, you can test by swapping them around but again if you don't get codes then it's point less. There is also the possibility of the eccentric shaft sensor going bad. But most likely you have a faulty ignition coil.. Start with the MAF and work your way down.

[GoRomeo]

Originally Posted by Delta0311

If you get no codes then I doubt is the VANOS, you can test by swapping them around but again if you don't get codes then it's point less. There is also the possibility of the eccentric shaft sensor going bad. But most likely you have a faulty ignition coil.. Start with the MAF and work your way down.

thanks again. Yeah i get no ECL or anything. Eccentric shaft sensor, dont think so. I checked the connector few months back and is completely dry no oil. Like I mentioned earlier, I tested each coil by disconnecting each one and all make difference when I unplug them so coils are good. I will start with cleaning the MAF I guess. I do have a K & N oiled air filter since I did charcoal delete few years ago, maybe my MAF sensor is dirty now...

[dangeris]

At idle I can feel the motor shutter a little. Off and on awhile ago but now more than ever. Again if I put the gas on at a light or even at cruising speed, the motor would actually hesitate then the rpm would kick in and the then CEL comes on and the power goes down hill from there. On a side note, I did replaced the stock airbox with a BMW performance box. I'm sure the MAF is dirty.

[markus037]

instead of throwing parts at it, get the car scanned. the car is telling you something is wrong.

[dangeris]

I did get it scanned and the only thing that came up was a small evap code.

[KenM302]

When's the last time you changed your oil?

[GoRomeo]

Actually, I need to change mine. Last time I changed mine was last December 2013. I dont drive much but still I need to change it. I will do it before this month ends.

[KenM302]

Friend of mine said my issue could be in not having changed the oil in 9k miles. Said the vanos solenoids are most likely clogged and or stuck. I have the same issues as the op but my cel comes on steady and does not flash with only dtc p0304. If driving lightly it will clear itself and shut the light off and drive normal until I lay into the gas a little bit. All of this mayhem typically starts right before the shift at or around 3k rpms which points in my case towards vanos solenoids. Any techs have any input? 2011 328i xDrive coupe n52 engine. All stock 59k miles.

[KenM302]

Just an update. Ran some liqui moly engine flush. Changed oil with M1 Euro 0w-40 and napa/wix filter. Plan to change oil every 5-6k from here on out. Anyway vanos solenoids both appeared to be clean. The oil was rather dirty seeing it was done at the local BMW dealer at 50k (March '14) now at 59k. I wanted to check the eccentric shaft sensor at this point so off came the engine cover and all the bs with it. Pulled the plug on the sensor and thankfully dry as a bone. Went back to the cylinder 4 misfire code. Pulled the coil and appeared to be no physical signs of damage or white marks. Pulled the plug and it was toast. Rounded off electrode. Proceeded to pull the rest of the coils and plugs. All the coils appeared to be in good shape. All the plugs like cylinder 4 were toast. Picked up a set of Denso Iridium Power plugs as NGKs weren't available locally (bs!!) and I personally don't like Bosch plugs. Drove the car home and first thing I noticed the onboard computer was showing my nearly 27mpg on the highway normal driving around 70-73mph. In the past I've never seen over 24mpg and anything higher was extremely rare. One thing I noticed the car seems to run hotter. The temp gauge is now nearly to the middle at 250 but never spiked or even crosses that middle line. All in all I would like to say misfire fixed but id like to give it a couple days for the computer to learn and readapt. If you read this whole post thanks for sticking it out. Sorry got long winded. Any feedback or recommendations? Thanks!