[335iOnATuesday]

So I've had this problem since before installing my jb4, since then all plugs and coils have been replaced. Also did a recent tranny flush and water pump battery etc.

2007 335i sedan 05/07 build
89k miles

From a cold start only, if I start and go, and by go I mean only going 10 mph or so down my street, my engine feels like it's coughing almost ? hard to explain, you can feel it softly jerk forward or something.

But after it does it a handful of times and the engine is more warmed up, the problem disappears.

If I cold start, and wait a few minutes (I usually wait for my tpms error light to stop blinking as a timer lol) it doesn't happen at all 100% of the time.

During just idle and not moving my RPM aren't bouncing everything sounds perfect. Only under acceleration and when in gear does this happen.

It doesn't bother me so much im just worried it's pointing out something worse. I've thought maybe a walnut blast? Someone suggested clean my solenoid...

Any advice or ideas are helpful

[335iOnATuesday]

Bump

[tampaturbom3]

how many miles do you have? and have you done a walnut blast yet?
I'm at 55k miles and just did the walnut/soda blast and I would highly recommend it if you haven't already and you're anything north of 40k miles.

[TheYuriPanda]

Offtopic. How did you get the tmps blinker for a timer?

[Mike@N54Tuning.com]

Why not datalog it with the JB4 since you have it. Might shed more light on the issue.

Mike

Originally Posted by 335iOnATuesday

So I've had this problem since before installing my jb4, since then all plugs and coils have been replaced. Also did a recent tranny flush and water pump battery etc.

2007 335i sedan 05/07 build
89k miles

From a cold start only, if I start and go, and by go I mean only going 10 mph or so down my street, my engine feels like it's coughing almost ? hard to explain, you can feel it softly jerk forward or something.

But after it does it a handful of times and the engine is more warmed up, the problem disappears.

If I cold start, and wait a few minutes (I usually wait for my tpms error light to stop blinking as a timer lol) it doesn't happen at all 100% of the time.

During just idle and not moving my RPM aren't bouncing everything sounds perfect. Only under acceleration and when in gear does this happen.

It doesn't bother me so much im just worried it's pointing out something worse. I've thought maybe a walnut blast? Someone suggested clean my solenoid...

Any advice or ideas are helpful

[BMW_drei]

In order of difficulty:
- Look at logs to see what's different
- Fuel system cleaner
- Clean/swap VANOS solenoids
- Clean intake valves

[enrita]

injectors leaking

[335iOnATuesday]

Originally Posted by enrita

injectors leaking

more explanation of why? wouldn't that cause problems post warming up also?

[shawntech]

nope, mine did exactly like this before injector replacement. hasn't happened since... walnut blasting did not resolve it either.

it did go away once warm even with bad injectors, but bank trims were ~15% apart at all times which alerted me to injectors.

[335iOnATuesday]

Originally Posted by ls3c6

nope, mine did exactly like this before injector replacement. hasn't happened since... walnut blasting did not resolve it either.

it did go away once warm even with bad injectors, but bank trims were ~15% apart at all times which alerted me to injectors.

Did you replace all 6 or just the problematic one?

Recently after replacing plugs, my dme mosfets fried (for cylinders 1-3), fixed that and replaced all 6 coils. Now I misfire on WOT for cylinders 1 and 3. I was suspecting the dme messed with my new spark plugs. Hmm..

[shawntech]

Originally Posted by 335iOnATuesday

Did you replace all 6 or just the problematic one?

Recently after replacing plugs, my dme mosfets fried (for cylinders 1-3), fixed that and replaced all 6 coils. Now I misfire on WOT for cylinders 1 and 3. I was suspecting the dme messed with my new spark plugs. Hmm..

replaced all, new index 11+ (mine are index 12) are not compatible with older versions in the same bank. This was after troubleshooting with new plugs, walnut blasting, cleaned vanos solenoid etc etc etc etc etc etc

for the record I never received a fault code / misfire under idle/load warm/cold or otherwise. Just ran like crap cold for no reason and jerked under light throttle cold, seemed to resolve warm with some stutter warm in the 40-50mph range in top gear (6AT)

runs perfect now, nice mpg gains too.... maintaining ~19mpg with a tuned E90 XI 6AT with 7mi trips to work in sub 0 weather!

[335iOnATuesday]

Exact same situation as me.. now I need to find the right Injectors for the cheapest possible

[spxxx]

Btw someone is selling a set of index 12 injectors on the forums for cheap NIB $700 I think...

[Chocolatethunder]

I would deff replace all of your injectors at once you don't wana have more of the same problems when you least ecpect it.

[335iOnATuesday]

Originally Posted by spxxx

Btw someone is selling a set of index 12 injectors on the forums for cheap NIB $700 I think...

Where ? Link ?

[jazredgt]

Mine is doing this in cold weather as well. But i just replaced my injectors nt even 3,000 miles ago with index 12! Once the car warms up it will run fine.

[TrollToll]

The op lost me at softly jerk