[G3ko]

Morning guys,

I have noticed a niggling issue with my BMW e90 330i . Basically at low RPM between idle at 2000 rpm in 2nd gear or above, if I press full throttle the car hesitate / jerks for a few seconds and then accelerates fine.

Now off some reading some people have had this and said coil packs could be the cause...

Does this sound likely? and could any tests be done to confirm the issue?

[Casca]

I'd try pulling the maf, clean it and reinstall. Pull both vanos, clean and reinstall swapping positionsaround. Very easy to do and cost is just for a can of maf cleaner.

[G3ko]

Sounds like an idea, but could they really cause that problem without fail ?

If I'm gentle accelerating I never get any stuttering

[gaza01]

Had this and it was the coil packs

[G3ko]

Originally Posted by gaza01

Had this and it was the coil packs

Seems like quite a common fault off reading a few posts over the internet. If I send it to my local bmw specialist wouldn't they most likely do the lot?

How much did it cost roughly to set right?

A new set of OEM coils online would run around $40-45 a piece times 6, you minus will do the spark plugs at the same time which are around $80 a set.

Cleaning the MAF with MAF sensor cleaner ONLY is always a good idea, have them pull your codes if your getting any Vanos codes, the best thing would be to remove the Vanos solenoids clean them and swapping the positions around.

Throwing in a can of Redline fuel system cleaner in the tank is also a good idea.

See what you get.

Your mileage would help, coil/plugs are around 100k intervals, is your check engine light on (SES)?

[Amini77]

Same it rarely happens though. I'll do it when I do my 100k mile tune up.

[Casca]

Originally Posted by G3ko

Sounds like an idea, but could they really cause that problem without fail ?

If I'm gentle accelerating I never get any stuttering

Yes, the MAF and/or VANOS can cause your car to hesitate on initial acceleration. And all you gotta do is pull them and clean them. Takes well under 30 minutes to accomplish if you take your time.

I drive my coil-packs to the ground and replace them when they actually fail. When they actually fail, you get misfire, motor runs rough, engine code. I didn't consider they can cause hesitation and not so sure that is true, but don't really know. What I do know is I had a hesitation as you described and it went away directly after cleaning the maf and repositioning and cleaning both vanos. Also, before that, I had already replaced all 6 coil-packs. 5 because they actually failed and the 6th just because.

[dtea604]

It could also just be that we have n52 engines and there's always that lag until you do a ecu remap and possibly one of the following scenarios bolt in cat back exhaust with an intake for the tune or tune, catless headers resonator delete intake work. A step up would be the intake manifold swap for guys without the 330i. But from what the other post are saying you do a full maintence from a reputable Indy and you will see the difference in your cars driving mechanics

[tigermack]

My car been having issues off cold-start. I have the BMS powerbox and the throttle response was lightning difference to stock, but now it takes more effort to get the rpm up after a cold-start. I reset the map and it'd be normal again... not sure if it's the BMS itself or something with the car? The car drives fine once I get it going... it's just first 2 gears is rough on taking off since input on throttle doesn't bring the rpm up much.

[G3ko]

Forgot to post this, the problem is gone... Darren wood BMW specialists just had to re-sit my throttle body. All is well now and has been for 2 months

[DaanBMW]

Originally Posted by G3ko

Forgot to post this, the problem is gone... Darren wood BMW specialists just had to re-sit my throttle body. All is well now and has been for 2 months

Can you give a bit more details ? What was it, what caused it, and how did he re-seat it ?

[cdgatti]

re-seat throttle body???? This is a new one. Find out what he did.

[Taskmaster]

Coil Pack was my issue.

[tigermack]

Not sure what re-seat means... lol

[DaanBMW]

Originally Posted by TheAxiom

Coil Pack was my issue.

Had codes ? If not, how did you figure it out ?

[Taskmaster]

Originally Posted by DaanBMW

Had codes ? If not, how did you figure it out ?

At first no, but I kept pushing to recreate the issue and eventually it caused a CEL which I had pulled. Depending on miles, I would look to replace the coils regardless.

[330xtrai]

Originally Posted by DaanBMW

Had codes ? If not, how did you figure it out ?

to find out which pack is bad just take off the engine cover and pull each coil pack one by one (disconnect one then reconnect it) with the engine on and see if it makes a difference in the idleing. if it does the coil is good if not its bad you could switch them to be sure about it. I think the channel BMtroubleU has a video on it.
edit: I found it.

[DaanBMW]

OK, so both axiom's and xtrai - you had hesitation but no codes ? how to trouble shoot I do understand, but what are the symptoms barring the appearance of codes ? at idle the engine should be 'chasing' or are the electronics that good nowadays that isn't the case anymore ?

I don't feel my idle is in any not smooth (to clear the double negation: idle is smooth), yet I feel upon acceleration there is a hesitation esp. if engine speed is a bit low when I step on it, like the car gets bogged down then all the sudden it wakes up - oh, you want me to speed up - kinda thing.

From all I've read replacing coils willy-nilly is not recommended, regardless of mileage.

[Taskmaster]

It happens exactly like that -

You try to accelerate from a lower RPM in a higher gear (like 1500-2000) in 2nd or 3rd and the car will stumble and then accelerate fine. It would consistently happen at the same rpm in the same gear, and I though it was a issue with the stock ECU just having hiccups.

When I installed my OE revised tune, the issue continued if not got worse. Now it's at the point now that it will actually trigger a CEL and cause the car to stumble at all RPM for a full cycle. It's not noticeable on WOT upshifts from 1st -4th, only on partial throttle/WOT in higher gears and lower RPM.

Be prepared for a coilpack replacement.

[DaanBMW]

Originally Posted by TheAxiom

It happens exactly like that -

You try to accelerate from a lower RPM in a higher gear (like 1500-2000) in 2nd or 3rd and the car will stumble and then accelerate fine. It would consistently happen at the same rpm in the same gear, and I though it was a issue with the stock ECU just having hiccups.

When I installed my OE revised tune, the issue continued if not got worse. Now it's at the point now that it will actually trigger a CEL and cause the car to stumble at all RPM for a full cycle. It's not noticeable on WOT upshifts from 1st -4th, only on partial throttle/WOT in higher gears and lower RPM.

Be prepared for a coilpack replacement.

Ok, thanks ! everything sounds like what I am experiencing. You got it throw a CEL/code by just keeping at it ? Did you replace all packs or just 1 (?) that caused it ?

[gudaev]

Hi! I'm currently experiencing something similar.
on 1.5-2K RPM upon moderate acceleration car starts jerking/hiccuping/shaking but eventually (after ~2 seconds) accelerating
I did some load testing and came to a conclusion that the issues deteriorates once the engine is warmed to a normal/above normal values. Eventually i think i made it to switch off one of the cylinders (i had a clear misfire on idle)
Yesterday i've checked the resistance of all 6 coils as it was suggested in one of the topics around here, but them all seemed fine (showing the same value). (however that is not the best way to test them as i understand)
During that procedure i also found some oil on the eccentric shaft sensor. The gasket there is clearly leaking...
I'm waiting for the ODB2 cable to get the codes checked and will keep you posted.