[Insane435]

Ever since I bough my 2011 328ix, I have noticed a rough idle when the car is not at operating temp. Once it reaches operating temp, I have never noticed this issue. The car never stalls or goes into limp mode but the rpms tend to just dip down to like 500 or a bit below and you can feel the car shake. When the weather is really cold, like 30 or below, the issue is much worse. I will also add, I have never had a problem starting the car, even in 10 degrees below zero.

I have got various misfire codes which led me to replace all of the plugs and coils. I am using the proper NGK plugs and delphi coils. While these always fixed my misfires, I have still notice the exact same idling issue.

Recently, I replaced my valve cover gasket and eccentric shaft sensor. I noticed that the eccentric shaft sensor gasket had oil seeping through and that it reached the electrical connection. I also replaced this gasket, as well as the valvetronic motor gasket and plug sleeves. I put the car back together, and it drives fine. It may actually be a bit more responsive with the new sensor, but that was never an issue.

However, after this install, the same type of rough idle before operating temperature is achieved persists. I do not believe this is related to a bad install because it didnt get any worse. I also made sure the gasket didnt get rolled. I can also confirm that the breather hose did not crack or break. I also cleaned both VANOS solenoids with compressed air.

What else could be causing this issue? This exact issue has been there from the moment i bought this car @54K miles. Should I maybe switch the VANOS solenoids or replace them altogether? I am unsure i want to replace these parts because they are about $130 a piece; if i knew they were the fix, however, then i would do it.

Recap of what I have replaced or tried:

Valve Cover Gasket
Eccentric shaft sensor
Eccentric shaft sensor gasket
Valetronic motor gasket
6 new NGK spark plugs
6 delphi coils
cleaned both vanos soleniods.
Pulled codes on 10/09/18 - no shadow codes stored.

EDIT: I need to clarify my statement about a rough idle. It doesn't idle rough, the RPMs dip down to like 500 when i come to a stop but then level back at the normal idle level which is 600-650. Then the car is smooth. That is my real issue.

[Biginboca]

Do you have an oiled air filter or the factory paper? If oiled I would try cleaning the MAF sensor.

Outside of that it really sounds like maybe a vacuum leak. Maybe a seal leaking somewhere when it’s cold and then as it heats expands and seals better. Are you getting lean codes? If so do a smoke test, there are ways shown online to make a diy smoke tester for around $20

[Insane435]

Originally Posted by Biginboca

Do you have an oiled air filter or the factory paper? If oiled I would try cleaning the MAF sensor.

Outside of that it really sounds like maybe a vacuum leak. Maybe a seal leaking somewhere when it’s cold and then as it heats expands and seals better. Are you getting lean codes? If so do a smoke test, there are ways shown online to make a diy smoke tester for around $20

I have the factory air filter still. Maybe I need to replace it? I am not sure when it was last done. I think I should do a fog test as well just to be safe.

[fravel]

Originally Posted by Insane435

I have the factory air filter still. Maybe I need to replace it? I am not sure when it was last done. I think I should do a fog test as well just to be safe.

How many miles are on car now? That's honestly one of the first things I would have done.

Have you tried scanning the car for codes? Not all of them will give you a check engine light.

I'd try running some Chevron Techron through it too.

[Insane435]

Originally Posted by fravel

How many miles are on car now? That's honestly one of the first things I would have done.

Have you tried scanning the car for codes? Not all of them will give you a check engine light.

I'd try running some Chevron Techron through it too.

68K

I should scan it, that is a good point and no i dont have any codes. I have tried the chevron at some point in the past but that didnt do anything major.

[fravel]

Originally Posted by Insane435

68K

I should scan it, that is a good point and no i dont have any codes. I have tried the chevron at some point in the past but that didnt do anything major.

So at least 14k miles since you've changed the air filter? I'd do that yesterday.

How about the engine oil?

[Insane435]

Originally Posted by fravel

So at least 14k miles since you've changed the air filter? I'd do that yesterday.

How about the engine oil?

I changed it about 4-5K miles ago.

[Insane435]

I need to clarify my statement about a rough idle. It doesnt idle rough, the RPMs dip down to like 500 when i come to a stop but then level back at the normal idle level which is 600-650. Then the car is smooth. That is my real issue.

Also, I pulled codes today and there are no shadow codes.

[Insane435]

Update, this car is cursed. I am now getting misfires on 2 cylinders. One of them just got a new coil 1 week ago (Delphi). I ordered 6 new plugs (NGKs) and 1 more new coil. I honestly do not know how this keeps happening. My plugs were replaced about 11 months ago and have about 15K miles on them.

What is wrong with my car...

[nsjames]

you need to start doing soe logging so you can look at what the DME is reacting too.

[Fritzer]

Originally Posted by Insane435

I changed it about 4-5K miles ago.

0W or 5W?

Did you change your engine air filter yet? Clear out the whole box and system up to the filter, often leaves and other unwanted debris can get inside.

Originally Posted by Insane435

Update, this car is cursed. I am now getting misfires on 2 cylinders. One of them just got a new coil 1 week ago (Delphi). I ordered 6 new plugs (NGKs) and 1 more new coil. I honestly do not know how this keeps happening. My plugs were replaced about 11 months ago and have about 15K miles on them.

What is wrong with my car...

Replace entire coil pack at the same time imo. I recommend Bosch coils personally. NGKs are great for N52. Definitely follow what nsjames says as well, gotta see the data for more conclusive diagnosis.

[rick100]

some guys were having issues with the delphi coils , something about them not fitting right or not seating right

I went ahead with bosh coils and everything is fine. Maybe read a little bit on that

Also make sure the coils connectors are seated right , take a look at the connectors on the cylinders that are not misfiring and compare. It could be something as easy as that.

[Insane435]

How to i data log the car?

Also, I cant remember if it was 0w30 or 5w30, either way i am due now for a change. Which mixture is better?

I will read up on the bosch coils because i wouldnt doubt the delphis fitment issues, they do seem really lose. Its also very odd my black top delphis are the ones that keep messing up. I still do not understand the difference between the white v black top Delphi coil. May they were different production runs? Ether way, the 3 i had to replace when i bought the car are the ones that are messing up every time..\

[Insane435]

bump

[Needbmwpartzz]

did you manually gap plugs and carefully insert them?
plugs get banged up easily...dont assume new means correct gap.
also i would put dielectric grease between coil and plug.
also check all air filter plumbing/clamps/screws/bolts/maf and intake manifold.

[Yangorang]

I have Delphi coils on NGK plugs in my 2008 328xi with no problems. The Delphi parts seem to fit pretty tight for me. I used a little bit of dielectric grease when installing but not much. I also checked gaps on the plugs before installation but they were all good already.

Did you swap/inspect parts to determine whether the new misfires move with the spark plugs or coils?

After you fix the misfires you can see if replacing VANOS solenoids or cleaning the MAF would help you any. Some people also have issues with the vanos check valves (11367541692) and the PCV integrated into the valve cover being clogged up. Unfortunately rough idle can be caused by a million different things.

[nsjames]

Originally Posted by Yangorang

I have Delphi coils on NGK plugs in my 2008 328xi with no problems. The Delphi parts seem to fit pretty tight for me. I used a little bit of dielectric grease when installing but not much. I also checked gaps on the plugs before installation but they were all good already.

Did you swap/inspect parts to determine whether the new misfires move with the spark plugs or coils?

After you fix the misfires you can see if replacing VANOS solenoids or cleaning the MAF would help you any. Some people also have issues with the vanos check valves (11367541692) and the PCV integrated into the valve cover being clogged up. Unfortunately rough idle can be caused by a million different things.

as do I. I checked all the plugs as they came out of the box and they were all bang on for the gap as well.

as for logging, do you have any diagnostics software/hardware? Ista?
as the engine controls air intake with valvetronic, a dip at idle indicates that either the DME is responding to something, or the valvetronic may not be responding properly.

[Insane435]

1) Logging, I do not have any of those programs, nor the obd2 cable or whatever i would need. I will look into doing this though in the coming weeks.

2) Oil, which brand, weight & viscosity should i use for winter to help the cold idle?

3) Plugs & Coils: I have 6 new NGK plugs coming from FCP euro (lifetime warranty), I plan on making sure i install these correctly. I think the gap is 0.044"? Coils, i will replace with the one new unit coming and make sure all 6 are sitting correctly with the plug in right. If this doesnt work, i plan on ordering 6 new bosch units. l

4) VANOS: I have cleaned both, but may consider replacing the soleniods. I would get brand new OE units if i do this.

5) Possibility of a Vacuum leak: may fog test the car, MAF has been cleaned before as well.

[Yangorang]

I use the BimmerGeeks ProTool BT adapter and app with android and it seems to work great.

[Insane435]

I replaced all 6 plugs again. They look pretty worn which seems extreme for 15K-20K miles on them. All of the gaps were at least .070", probably because of the wear. Not sure how this is happening.

[nsjames]

mine looked similar with 40K on them.

car still ran fine. I only replaced them because I was doing the alve cover, and it's just too easy not too.

[bluewater328]

Originally Posted by Insane435

I replaced all 6 plugs again. They look pretty worn which seems extreme for 15K-20K miles on them. All of the gaps were at least .070", probably because of the wear. Not sure how this is happening.

That isn't that bad. Buildup seems fairly minimal. And while the gap is worth consideration, the rest of it looks decent.