[cdavi060]

I have an issue with my 06 330i now that once the engine is warmed up, only at idle, I will have random misfires or idle hiccups. This issue does not seem to exist in the winter, and seems to be worst in summer where humidly is higher and when A/C is on. You can feel it in the car when it happens easily. The car performs fine when driving. This is only at idle. The issue will not produce a code. Any idea what could be going on??

Video 1 of idle blips

Video 2 of idle blips

[bimmerquick43321]

I had something similar, same it was worse with the A/C, after changing gaz it helped (ironicly I was running shell vpower 91 that everyone praises, however the car was much smoother with the 94 from petro canada even if ethanol...), but went completly away after changing ignition coils/spark plugs, now I can run the shell with no idle issues either.... not saying you need to change those, but it sur looks similar to what I had...

[VTECaddict]

One (or more) of the coils is going out. I had this go on for a long time before it finally threw a misfire code. Sadly you can't pinpoint which coil it is unless you get a code or you spend the time to test a new one in each cylinder until it stops. Or you can just replace all of them together (and the spark plugs since you're in there already).

[cdavi060]

I was leaning toward a bad coil but was not sure since it performs fine during actual driving. No chance of a faulty injector right?

[Three_thirty_I]

I would suggest having the "smooth running" checked via live data diagnostics to see if it is within spec. There may be a coil issue, but it is tricky to determine if it is not bad enough to throw an error code or actual misfire. If you have access to another car like yours, you can always swap try those coil packs in your car as a test before spending money replacing them.

[cdavi060]

Originally Posted by Three_thirty_I

I would suggest having the "smooth running" checked via live data diagnostics to see if it is within spec. There may be a coil issue, but it is tricky to determine if it is not bad enough to throw an error code or actual misfire. If you have access to another car like yours, you can always swap try those coil packs in your car as a test before spending money replacing them.

Sadly, I don't have access to another car and I hope to not have to pay a diag fee. That's what this forum and knowledgebase of people are for

[Three_thirty_I]

Unfortunately the best way to approach problems like this is to get it on a diagnostics machine, and I am sure there are good indy shops that can do this for a lot less than the dealerships. They will first check for any stored faults, but then with the engine running they can check the smooth running parameters which would pick up misfires and any other issues with each combustion chamber - I had some dirt in the fuel rail that was affecting the no.1 cylinder (basically that injector was not spraying properly) and in turn caused an over-corrected taking it out of spec. Luckily it was just some dirt, and after they cleaned the fuel rail and all injectors in an ultrasonic bath, all was fine and within spec. Not saying that this is what you have, but would let them check that just to be sure.

[Jashley73]

I'm intersted in this as well, as my car has an intermittent, lumpy idle now... I've started to notice it now that it's hotter outside, with the MAX A/C running especially. It will be idling fine, then go into a slow, oscillating idle, then calm down for a few moments. It's bad enough that I've seen it spike down around 400rpm, then up to 1000, and finally settle back down, but you can hear the cabin fan/blower sound change as the motor is hunting for the correct idle speed.

I'm pretty sure I've seen it do the quick blips too, and just yesteray, it actually died while I was clutch-in coasting around 20mph or so. I turned to my wife, and was like, "Did it really just die on us?:

[cdavi060]

Originally Posted by Three_thirty_I

Unfortunately the best way to approach problems like this is to get it on a diagnostics machine, and I am sure there are good indy shops that can do this for a lot less than the dealerships. They will first check for any stored faults, but then with the engine running they can check the smooth running parameters which would pick up misfires and any other issues with each combustion chamber - I had some dirt in the fuel rail that was affecting the no.1 cylinder (basically that injector was not spraying properly) and in turn caused an over-corrected taking it out of spec. Luckily it was just some dirt, and after they cleaned the fuel rail and all injectors in an ultrasonic bath, all was fine and within spec. Not saying that this is what you have, but would let them check that just to be sure.

I have purchased new coils and plugs. I will swap them in and see what happens. It has gotten worse and now under initial acceleration it shudders now. I am really thinking its coils/plugs. If the problem is still there, I'll move to paying a shop to diagnose. BMWhat OBD tool did not find any BMW codes.

Originally Posted by Jashley73

I'm intersted in this as well, as my car has an intermittent, lumpy idle now... I've started to notice it now that it's hotter outside, with the MAX A/C running especially. It will be idling fine, then go into a slow, oscillating idle, then calm down for a few moments. It's bad enough that I've seen it spike down around 400rpm, then up to 1000, and finally settle back down, but you can hear the cabin fan/blower sound change as the motor is hunting for the correct idle speed.

I'm pretty sure I've seen it do the quick blips too, and just yesteray, it actually died while I was clutch-in coasting around 20mph or so. I turned to my wife, and was like, "Did it really just die on us?:

I have what feels like a misfire or a engine kick. It's not so much a fluctuation in RPM as your describing.

[SPJR]

I started experiencing a similar issue on idle and having the A/C on. It almost feels like the engine is going to stall out. I also noticed it under heavy acceleration, there is a bit of a hiccup and jitter. It definitely feels like an issue with coilpacks/plugs. Would be interested if that would fix your problems once you swap them out.

[Three_thirty_I]

Originally Posted by cdavi060

I have purchased new coils and plugs. I will swap them in and see what happens. It has gotten worse and now under initial acceleration it shudders now. I am really thinking its coils/plugs. If the problem is still there, I'll move to paying a shop to diagnose. BMWhat OBD tool did not find any BMW codes.



I have what feels like a misfire or a engine kick. It's not so much a fluctuation in RPM as your describing.

My E46 had some coils that became weak or faulty, this was causing a noticeable stutter or misfire when moving on from yield stops in 2nd or 3rd gear, other than that the engine ran fine. But I then tried a set that came out of a Z4 3.0i with the same type of coils with three that had failed - the idea was to stick the tree that were marked (presumably as failed or not failed) and see what happens. They seemed to all be faulty and caused the engine to barely run! So definitely a case of completely failed coils versus ones that were just on the way out. At the end of the day, replacing coils and plugs is not at all a bad plan or a total waste of money, they do eventually need replacing.

Holding thumbs that this sorts the problem out!

[cdavi060]

Just wanted to provide everyone with an update. Replaced all 6 spark plugs and problem is completely gone.

[Three_thirty_I]

Originally Posted by cdavi060

Just wanted to provide everyone with an update. Replaced all 6 spark plugs and problem is completely gone.

That is good to hear! If possible, maybe post some pics of the old plugs?

[cdavi060]

Originally Posted by Three_thirty_I

That is good to hear! If possible, maybe post some pics of the old plugs?

Unfortunately 24 hours after I confirmed the plugs fixed the issue, I tossed them. For what it's worth, they looked exactly like the ones in the below article.

http://www.e90post.com/forums/showthread.php?t=174217

[Dylanize]

Originally Posted by cdavi060

Just wanted to provide everyone with an update. Replaced all 6 spark plugs and problem is completely gone.

Only the plugs? Not coils too?

[cdavi060]

Originally Posted by Dylanize

Only the plugs? Not coils too?

Correct. Only the plugs.

[Three_thirty_I]

Well, holding thumbs that this has solved the problem and lasts!

[VTECaddict]

I'm getting this problem again. My plugs only have about 25k on them. Probably another coil going out.

[Three_thirty_I]

Originally Posted by VTECaddict

I'm getting this problem again. My plugs only have about 25k on them. Probably another coil going out.

Always replace the entire set, because generally, if one fails, you can be sure the rest will follow soon enough.