Intermittant rough idle 330i

[M3 Saloon]

Hi guys, i've been reading through many similar posts on here and can find some answers but nothng that appears to be exactly like my problem.

I have only owned my 330 touring for a few weeks and and coming from my e36 M3 is nice and comfy and easy to drive.

What i noticed straight away was the throttle response delay. I have carried out the recalibration and throttle reset but being honest have not really noticed an improvement. might just take some getting used to.

After doing around 500 miles trouble free the emissions light came on with no warning or apparent bad running. Since then the idle has been on occasions slightly rough but not all the time.

Some mornings when i first start the car the idle can hunt for a few seconds and then settle at around 6-700 rpm. Sometines, not all the time when i go to pull off slowly its almost like ive not given enough revs and the revs can drop to the point where it feels like its going to stallso have to dip clutch and go again. I am giving enough initial revs because sometimes the revs jump to 2k. Almost like a splutter.

Once been driving for a bit (20 miles or so) with no issues i can stop at a junction and although wont stall, the idle again can hunt for a few secs before settling.

Then yesterday when picking kids up from my parents when i pulled away it felt like it was running on 5 cylinders. After a few hundred yards it sorted itself out and ran fine the rest of the way home.

Ive disconnected the MAF and it appears to idle better and today ive done 100 miles with no idles hesitations or issues.

Assuming MAF i replaced this tonight (albeit a ECP par NOT genuine) but idles as bad as before and the emissions light remained on.

Can anything else be causing this type of issue? I assume an air leak on the intake boot but i sprayed this with brake cleaner the other day and engine note stayed the same, no increase in revs

Are any other sensors used along with the MAF that stop being used when the MAF is disconnected that could be causing this?

Sorry for the long post, hopefully some of the very clued up guys on here can offer some advice from experience?

I am having the codes read first thing tomorrow but would like to get a heads up before hand if possible.

Thanks, Ashley

[B0B]

You seem to have looked in the usual places.

Inspect the lower intake boot, paying particular attention where it T's off to the idle control valve as that's where they tent to split.

You could clean the idle control valve because if its gummed up and sticking it will give an erratic idle.

Check the f connector on the I take boot the smaller pipe was perished on mine (it connects to the pressure regulator on the fuel filter) give it a gentle tug to see if it is connected to the fuel filter at the other end.

Worth checking the disa valve, whip it out and make sure the valve part is ok and if it is put it all back with a good dollop of I start gasket to make sure no air is testing in.

Failing all of the above and presuming the codes come back clear it could be a split vacuum hose on the CCV.

Hope that helps

Bob

[Chimp Choker]

Id personally do a physical check of both intake boots.

In regard to the MAF you say it ran better unplugged id return the new part as this could be faulty.

One other thing you could try is to clean the old MAF with electronic contact cleaner

Sent from my GT-N7100 using Tapatalk 2

[M3 Saloon]

Thanks you for the information guys.

Forgot to add that i did remove and clean the original MAF with electrical contact cleaner. The new ECP MAF is going back.

Had the car plugged in this morning and the following came back

Intake camshaft sensor

Lambda bank 1

Lambda bank 2

Inefficient catalytic converter

Sensor on cylinder 5

Fuel breather valve

Ignition range

I'm hoping most of the above are linked to the same fault.

For £35 i'm going to replace the camshaft sensor, could this be the route cause?

At the weekend i'll remove the intake boots and check them over properly.

Can you explain CCV? and F connector? just so i understand what they are and what i'm looking for.

The fuel pump is quite noisy on mine too, is it worth changing fuel filter to see if it helps?

Thanks again, appreciate the advice

Ash

[B0B]

Post #59 shows a pic of the F connector http://www.e46zone.com/forum/topic/43553-330ci-error-codes-10-of-them/page-3

CCV here http://www.e46zone.com/forum/topic/41420-how-to-replace-your-ccv-valve-m54-engine/

They may all be related its hard to tell

It looks like a cam sensor and fuelling issue of some sort,

I have had lean bank 1 and 2 codes (codes 227 228 or P0171 & P0174 IIRC) recently that turned out to be a soft fail of the MAF, meaning it was working most of the time.

I would put the code numbers into gooogle and see what it spits out.

Hope that helps

Bob

[M3 Saloon]

Thanks BOB, yes great help. The sensor is in stock so will do it tonight (weather permitting) or over the weekend.

If it does not sure it i may look into a genuine MAF and go from there.

The F pipe makes sense now lol The small connecting hose on mine looks a little perished but i soaked it in brake cleaner and didn't seem to notice a change in engine tone. I may have it all out and replace as well as a matter of eliminating the cheper parts.

Cheers again, i'll keep this updated. Any further advice or recomendations are welcomed

[quackers]

I'm not a 100% sure but the cam sensor fault may need to be cleared after you put a new sensor on.

[M3 Saloon]

I fittted the new cam sensor and in the process found the intake hose was perished on the underside where it flexes. Quite suprised i didn't notice it before and even when soaked in brake cleaner there was no evidence of an air leak.

So £17 later and a new intake hose fitted and i thought all was well.

The codes were cleared, emission light off and away i went.

Much smoother at idle and drives great but after 30 miles the emissions light has returned...... bugger

So hoping to get it plugged in again soon to see what it shows now.

Bit pissed to be honest because it drives spot on and thought i'd found the issue, obviously ticked one fault off the list but still more gggrrrrrrrr

[FAB_BMW]

Did you change both Camshaft sensors? As there is an inlet and exhaust sensor. It's usually worth changing the pair. One other 'test' you can perform is unplugging the VANOS solenoid on the inlet side, it's the one on the right hand side as you look at the engine. This will put the VANOS into default mode, effectively deactivating it, this way you can discount the VANOS from causing it. Go for a drive, the car will feel dull below 3k but that's normal.

[M3 Saloon]

I think i read that the inlet is for the low doewn power and exhaust for top end?

When foot to the floor there is a definate kick around 3.5K so i think the top end is certianly pulling ok.

When i left home today the car felt lumpy and was possibly only running on 5 cylinders for a mile or so before clearing and running fine again.

I wonder if this could be the cylinder 5 sensor fault that was on the original fault list? Does anyone know what the cylinder sensor is? i asked if it was likely to be a coil pack but was told there may be some sort of sensor on each cylinder. not something ive heard of before though.

The other thing i'll check when i get a chance is the lower intake hose. I suppose if the top hose nearesd the MAF was perisherd, maybe the lower one is too. Bit more of a pig to get to though.

FAB_BMW, by disconnecting the VANOS solenoid, is this the connector that goes to the cylindrical solenoid that i removed to access the inlet cam sensor? to the left of the oil filter?

Edited May 26, 2013 by M3 Saloon

[B0B]

Defineatley check the lower intake boot as it is the one prone to slitting at the junction where it t's off the the ICV.

If the think a coil pack maybe on the way out on cylinder 5 then swap it with cylinder 6 and see if the misfire changes cylinders.

Yes it's the connector on the solonoid you had to remove to,replace the inlet cam sensor.

[M3 Saloon]

Cheers again B0B, is it ok to drive with the Vanos solenoid disconnected?

had a couple of small misfires today when pulling away from junctions.

getting the codes read again in the morning.

See what shows up this time. Good idea about swapping the coil pack, if the cylinder 5 fault is there again i'll try that.

Cheers

[B0B]

I think fab just meant disconnect the vanos, go for a drive see if its a any different, for diagnostic purposes.

Getting the codes read is always the way to go

Let us know what they say

[M3 Saloon]

Well had the codes read this morning and the list is getting smaller.

To be honest quite pleased only 2 codes showing currently.

228 Lambda regulation bank 2

241 Ignition circuit cylinder 4

As mentioned the car had definately had a slight miss from time to time.

Is this likely to be a coil pack on 4 and causing the lambda code?

When i had the codes read first time it was cylinder 5 but this has not returned.... yet.

What do you think guys? likely to be coilpack related or not?

As always suggestions welcome.

EDIT: having just read up on the fault code 241 i found this

Crankshaft speed/acceleration is

monitored by crank sensor. Time for

each cylinder combustion is

compared against avg. of others. If

time for cylinder 4 is longer, fault will

set

Does this mean it could be a crank sensor? would this explain why both cylinder 5 and 4 have shown at separate occasions?

Ash

Edited May 29, 2013 by M3 Saloon

[Quiksilver_TR]

A miss-fire from a dodgy coil or spark plug will bring up the lambda error as the reading at the lambda wont be right due to the incorrect burn from the cylinder with the dodgy spark plug or coil.

Id be inclined to pop the spark plugs to check their condition.

Then clear the fault codes, run the car to get the fault code back.

See what cylinder the fault relates to.

Then firtsly swap the spark plug for another one without an error code present, eg cylinder 4 to cylinder 1.

Clear codes then fire car up to get codes back, read code to see where the error is now.

If the error moves to cylinder 1 then the issue is with the spark plug.

If the error stays at cylinder 4 then id swap the plugs back and repeat the process with the coil pack.

That should identify if is coil or spark plug.

If the error doesnt move with either of these then you may want to investigate the wiring to make sure thats not the cause.

Edited May 29, 2013 by Quiksilver_TR

[B0B]

Yep, as has been said it looks like a dodgy coil pack or plug.

The 228 code is registering a bad fuel/air mix pre cat for bank 2 (cylinders 4-6) which it will if you have a missfire, because of the unburnt fuel.

The 241 code is just saying the ignition timing on cylinder 4 is out, which it will be if its not giving a big fat spark

[M3 Saloon]

Thanks guys, much appreciated.

Think i'll replace plugs along with oil change anyway as general serviceable items that are probably due.

I'll then look into the possible coilpack. So unlikely the crank sensor causing the 241 code?

Ash