[Iamstig335]

Guys, hoping for some advice from experiences you may have had.

My 2007 335xi has 51k miles on it.
Have been running Cobb Stage 1 aggressive for 3 weeks now but otherwise 100% stock.

I've always run Shell 93 oct in my car so I know that's not the issue. Also my plugs were changed @5,000 miles ago.

I have an auto trans and when the car is in 2nd and 3rd gear WOT around 3-4k rpms the car starts hiccuping/hesitating.

It only last a fraction of a second and I can only relate it to feeling like your breaking traction but your not.

This is extremely annoying and it's not causing any lights to come on or codes to be stored so does that rule out coil packs or injectors?

Any advice would be great from those that have had this issue in the past.

[6MTE92]

Originally Posted by Iamstig335

Guys, hoping for some advice from experiences you may have had.

My 2007 335xi has 51k miles on it.
Have been running Cobb Stage 1 aggressive for 3 weeks now but otherwise 100% stock.

I've always run Shell 93 oct in my car so I know that's not the issue. Also my plugs were changed @5,000 miles ago.

I have an auto trans and when the car is in 2nd and 3rd gear WOT around 3-4k rpms the car starts hiccuping/hesitating.

It only last a fraction of a second and I can only relate it to feeling like your breaking traction but your not.

This is extremely annoying and it's not causing any lights to come on or codes to be stored so does that rule out coil packs or injectors?

Any advice would be great from those that have had this issue in the past.

Sounds like throttle closures from overboost condition. Try switching to the beta version 402 maps as they have massaged PID tables for better boost control. Also, this post is somewhat useless without logs. Get some logs see what can see what is occuring during these hiccups.

[Iamstig335]

Thanks for the quick response. I'm still pretty new to the Cobb AP but I'll try to pull a data log this weekend. What specific variables would I be looking at besides boast and rpms to shed some light?

I think I'll take your advice and try the beta version map also.

Have people had better luck with that update?

[enrita]

Originally Posted by Iamstig335

Thanks for the quick response. I'm still pretty new to the Cobb AP but I'll try to pull a data log this weekend. What specific variables would I be looking at besides boast and rpms to shed some light?

I think I'll take your advice and try the beta version map also.

Have people had better luck with that update?

there is a thread in how to log, search for it.

[rader1]

Originally Posted by Iamstig335

Thanks for the quick response. I'm still pretty new to the Cobb AP but I'll try to pull a data log this weekend. What specific variables would I be looking at besides boast and rpms to shed some light?

I think I'll take your advice and try the beta version map also.

Have people had better luck with that update?

Here's the thread on logging(i wish they would sticky that damn thing lol)
http://www.e90post.com/forums/showth...talogging+cobb

Post up the log in that thread, the cobb info thread, here or email it to Cobb for analysis.

More than like it's just boost oscillations and 4.02 should take care of it.

[Iamstig335]

Perfect thanks rader1 that's exactly what I was looking for.

Really appreciate the help all.

[pimple]

Misfire. Replace coils.

[BlueBimmer]

Originally Posted by 6MTE92

Sounds like throttle closures from overboost condition. Try switching to the beta version 402 maps as they have massaged PID tables for better boost control. Also, this post is somewhat useless without logs. Get some logs see what can see what is occuring during these hiccups.

I think the latest beta maps for stage 1 are 4.01, I'm running them with no problems though.

[MDORPHN]

I wouldn't rule out gunked-up intake valves, either.

Neil

[Iamstig335]

Originally Posted by BlueBimmer

I think the latest beta maps for stage 1 are 4.01, I'm running them with no problems though.

Did you notice any major difference when you switched to the beta map?

[Iamstig335]

Wow guess I should have knocked on wood when I posted this. Was out for a quick drive on my afternoon break and all of a sudden under throttle had multiple hiccups and then check engine light. Shut off car and cycled it back on and it's still there.

So when I get home from work I'll pull the code. Hopefully nothing too major :-/

[Iamstig335]

Just pulled the 2 codes:

P2DC3 monitoring terminal 15
P29CE misfire cylinder 2

Little help guys.

[6MTE92]

Originally Posted by Iamstig335

Just pulled the 2 codes:

P2DC3 monitoring terminal 15
P29CE misfire cylinder 2

Little help guys.

Either plugs or coils. Move coil for cylinder #2 to another cylinder and see if the misfire follows it. If it does then change the coil. If not change your plugs.

[Jeff@TopGearSolutions]

http://www.e90post.com/forums/showthread.php?t=631829

[Iamstig335]

Originally Posted by 6MTE92

Either plugs or coils. Move coil for cylinder #2 to another cylinder and see if the misfire follows it. If it does then change the coil. If not change your plugs.

Ya since the plugs were just changed at the dealership <5,000 miles ago I guess I'll start with coil packs and hope.

Am I doing my engine any harm in the meantime til I get the parts shipped and put it? Would switching to stock map be better?

[taylors335]

Mine does it too sometimes with jb4 , make sure your DTC is all the way off sometimes that helps

[Iamstig335]

Just finished flashing to map0 (stock) and went out for a drive. No hesitation or check engine light but seriously missing the powerrrrrrrr of the tune.

Gonna place an order tomorrow for a coil pack, is it strange though that cylinder 2 is perfectly fine?

If the coil pack is toast shouldn't it still reflect that even though I'm pushing less boost through?

Forgive me in advance for the newb questions.

[pimple]

Save yourself some headache later. Replace all 6 coils at the same time.

[Iamstig335]

Originally Posted by pimple

Save yourself some headache later. Replace all 6 coils at the same time.

Personal history with this issue I'm guessing? Can you recap how replacing them went for you?

Did you replace one, only to find out a few weeks later another one was bad and so on?

[skinrock]

Originally Posted by pimple

Save yourself some headache later. Replace all 6 coils at the same time.

If you like throwing away $300 without troubleshooting, go right ahead. It doesn't make a lot of sense to replace all of them if there is only a misfire in one cylinder.

OP, you should follow Jeff's sticky and swap the pack to see if the misfire moves. If it doesn't, it's something else with that cylinder - i.e. plug or injector. Even if you "just" replaced the plug, that doesn't rule it out - while it would be unlikely, you could just have a bad one or it wasn't gapped or installed properly, anything's possible.

[pimple]

Originally Posted by Iamstig335

Personal history with this issue I'm guessing? Can you recap how replacing them went for you?

Did you replace one, only to find out a few weeks later another one was bad and so on?

Yup. Also own an '07 AT. 3 coils within about 2k miles at around 50k total miles. Same early symptom as yours, WOT midrange RPM hiccup, each time. No CEL until the third time, but only after a few days. 2 times replaced by the dealer. 3rd time, just out of warranty, replaced all coils and plugs myself. No issues since.

[Iamstig335]

Update: I followed the coil pack swap DIY process that you guys linked.

Sure enough the misfire followed the pack so I just swapped it out.

Hopefully it will be many problem free miles until the next pack goes.

Thanks everyone for the input on this forum. Saved me a lot of $$.